| Please add updates@feedmyinbox.com to your address book to make sure you receive these messages in the future. | |
| Photomodulatable fluorescent proteins for imaging cell dynamics and cell fate.
April 2, 2010 at 6:04 AM
|
| | Photomodulatable fluorescent proteins for imaging cell dynamics and cell fate. Organogenesis. 2009 Oct;5(4):135-44 Authors: Nowotschin S, Hadjantonakis AK An organism arises from the coordinate generation of different cell types and the stereotypical organization of these cells into tissues and organs. Even so, the dynamic behaviors, as well as the ultimate fates, of cells driving the morphogenesis of an organism, or even an individual organ, remain largely unknown. Continued innovations in optical imaging modalities, along with the discovery and evolution of improved genetically-encoded fluorescent protein reporters in combination with model organism, stem cell and tissue engineering paradigms are providing the means to investigate these unresolved questions. The emergence of fluorescent proteins whose spectral properties can be photomodulated is one of the most significant new developments in the field of cell biology where they are primarily used for studying protein dynamics in cells. Likewise, the use of photomodulatable fluorescent proteins holds great promise for use in developmental biology. Photomodulatable! fluorescent proteins also represent attractive and emergent tools for studying cell dynamics in complex populations by facilitating the labeling and tracking of individual or defined groups of cells. Here, we review the currently available photomodulatable fluorescent proteins and their application in model organisms. We also discuss prospects for their use in mice, and by extension in embryonic stem cell and tissue engineering paradigms. PMID: 20357970 [PubMed - in process] | | |
| AID-induced T-lymphoma or B-leukemia/lymphoma in a mouse BMT model.
April 2, 2010 at 6:04 AM
|
| | AID-induced T-lymphoma or B-leukemia/lymphoma in a mouse BMT model. Leukemia. 2010 Apr 1; Authors: Komeno Y, Kitaura J, Watanabe-Okochi N, Kato N, Oki T, Nakahara F, Harada Y, Harada H, Shinkura R, Nagaoka H, Hayashi Y, Honjo T, Kitamura T Activation-induced cytidine deaminase (AID) diversifies immunoglobulin through somatic hypermutation (SHM) and class-switch recombination (CSR). AID-transgenic mice develop T-lymphoma, indicating that constitutive expression of AID leads to tumorigenesis. Here, we transplanted mouse bone marrow cells transduced with AID. Twenty-four of the 32 recipient mice developed T-lymphoma 2-4 months after the transplantation. Surprisingly, unlike AID-transgenic mice, seven recipients developed B-leukemia/lymphoma with longer latencies. None of the mice suffered from myeloid leukemia. When we used nude mice as recipients, they developed only B-leukemia/lymphoma, presumably due to lack of thymus. Analysis of AID mutants suggested that an intact form with SHM activity is required for maximum ability of AID to induce lymphoma. Except for a K-ras active mutant in one case, specific mutations could not be identified in T-lymphoma; however, Notch1 was constitutively activated in mo! st cases. Importantly, truncations of Ebf1 or Pax5 were observed in B-leukemia/lymphoma. In conclusion, this is the first report on the potential of AID overexpression to promote B-cell lymphomagenesis in a mouse model. Aberrant expression of AID in bone marrow cells induced leukemia/lymphoma in a cell-lineage-dependent manner, mainly through its function as a mutator.Leukemia advance online publication, 1 April 2010; doi:10.1038/leu.2010.40. PMID: 20357822 [PubMed - as supplied by publisher] | | |
| Disparate Companions: Tissue Engineering Meets Cancer Research.
April 2, 2010 at 6:04 AM
|
| | Disparate Companions: Tissue Engineering Meets Cancer Research. Cells Tissues Organs. 2010 Apr 2; Authors: Tilkorn DJ, Lokmic Z, Chaffer CL, Mitchell GM, Morrison WA, Thompson EW Recreating an environment that supports and promotes fundamental homeostatic mechanisms is a significant challenge in tissue engineering. Optimizing cell survival, proliferation, differentiation, apoptosis and angiogenesis, and providing suitable stromal support and signalling cues are keys to successfully generating clinically useful tissues. Interestingly, those components are often subverted in the cancer setting, where aberrant angiogenesis, cellular proliferation, cell signalling and resistance to apoptosis drive malignant growth. In contrast to tissue engineering, identifying and inhibiting those pathways is a major challenge in cancer research. The recent discovery of adult tissue-specific stem cells has had a major impact on both tissue engineering and cancer research. The unique properties of these cells and their role in tissue and organ repair and regeneration hold great potential for engineering tissue-specific constructs. The emerging body of evidence! implicating stem cells and progenitor cells as the source of oncogenic transformation prompts caution when using these cells for tissue-engineering purposes. While tissue engineering and cancer research may be considered as opposed fields of research with regard to their proclaimed goals, the compelling overlap in fundamental pathways underlying these processes suggests that cross-disciplinary research will benefit both fields. In this review article, tissue engineering and cancer research are brought together and explored with regard to discoveries that may be of mutual benefit. PMID: 20357428 [PubMed - as supplied by publisher] | | |
| Parallel Effects of Cations on PNIPAM Graft Wettability and PNIPAM Solubility.
April 2, 2010 at 6:04 AM
|
| | Parallel Effects of Cations on PNIPAM Graft Wettability and PNIPAM Solubility. ACS Appl Mater Interfaces. 2010 Feb 24;2(2):452-8 Authors: Fu H, Hong X, Wan A, Batteas JD, Bergbreiter DE Stimuli-responsive surfaces grafted with thermoresponsive polymers switch from hydrophilic to hydrophobic thermally, making these surfaces attractive in applications such as in microfluidics devices, as antifouling surfaces, and in cell culture and tissue engineering. These materials exhibit changes in wettability as the polymer undergoes a phase transition above its lower critical solution temperature (LCST). Because the presence of salts affects LCSTs in accordance to the Hofmeister series, salt effects on the wettability of these thermoresponsive surfaces will dramatically impact device performance. Prior studies of such effects have focused on the influence of anions. Detailed studies of the effects of cations have not been carried out. Here, the influence of varying cation identity in a series of mono-, di-, and trivalent sulfate salts on the wettability of a stimuli-responsive grafted surface was investigated by measuring advancing water contact angle (Theta! (a)) changes. The cation-induced changes in Theta(a) were correlated with corresponding changes in surface morphology examined by AFM. The results showed that the effects of varying cations on surface wettability are as large as the effects of varying anion identity and concentration (i.e., Theta(a) changes of up to 90 degrees). Parallel studies of the effects of varying the cation identity and concentration for these same cation sulfate salts in solution show that cation variation also has a large effect on the LCST of PNIPAM, the stimuli responsive polymer component of the nanocomposite grafts that were studied. Moreover, analyses of the Theta(a) and LCST data using activity showed that the Theta(a) or LCST versus cation activity/concentration could be readily grouped by charge. Such differences are not seen in similar studies where anion identity, charge, and concentration are changed. PMID: 20356191 [PubMed - in process] | | |
| Micropatterning of proteins and Mammalian cells on indium tin oxide.
April 2, 2010 at 6:04 AM
|
| | Micropatterning of proteins and Mammalian cells on indium tin oxide. ACS Appl Mater Interfaces. 2009 Nov 25;1(11):2592-601 Authors: Shah SS, Howland MC, Chen LJ, Silangcruz J, Verkhoturov SV, Schweikert EA, Parikh AN, Revzin A This paper describes a novel surface engineering approach that combines oxygen plasma treatment and electrochemical activation to create micropatterned cocultures on indium tin oxide (ITO) substrates. In this approach, photoresist was patterned onto an ITO substrate modified with poly(ethylene) glycol (PEG) silane. The photoresist served as a stencil during exposure of the surface to oxygen plasma. Upon incubation with collagen (I) solution and removal of the photoresist, the ITO substrate contained collagen regions surrounded by nonfouling PEG silane. Chemical analysis carried out with time-of-flight secondary ion mass spectrometry (ToF-SIMS) at different stages in micropatterned construction verified removal of PEG-silane during oxygen plasma and presence of collagen and PEG molecules on the same surface. Imaging ellipsometry and atomic force microscopy (AFM) were employed to further investigate micropatterned ITO surfaces. Biological application of this micropa! tterning strategy was demonstrated through selective attachment of mammalian cells on the ITO substrate. Importantly, after seeding the first cell type, the ITO surfaces could be activated by applying negative voltage (-1.4 V vs Ag/AgCl). This resulted in removal of nonfouling PEG layer and allowed to attach another cell type onto the same surface and to create micropatterned cocultures. Micropatterned cocultures of primary hepatocytes and fibroblasts created by this strategy remained functional after 9 days as verified by analysis of hepatic albumin. The novel surface engineering strategy described here may be used to pattern multiple cell types on an optically transparent and conductive substrate and is envisioned to have applications in tissue engineering and biosensing. PMID: 20356132 [PubMed - in process] | | |
| Immobilization of biomolecules on the surface of electrospun polycaprolactone fibrous scaffolds for tissue engineering.
April 2, 2010 at 6:04 AM
|
| | Immobilization of biomolecules on the surface of electrospun polycaprolactone fibrous scaffolds for tissue engineering. ACS Appl Mater Interfaces. 2009 May 27;1(5):1076-85 Authors: Mattanavee W, Suwantong O, Puthong S, Bunaprasert T, Hoven VP, Supaphol P To make polycaprolactone (PCL) more suitable for tissue engineering, PCL in the form of electrospun fibrous scaffolds was first modified with 1,6-hexamethylenediamine to introduce amino groups on their surface. Various biomolecules, i.e., collagen, chitosan, and Gly-Arg-Gly-Asp-Ser (GRGDS) peptide, were then immobilized on their surface, with N,N'-disuccinimidylcarbonate being used as the coupling agent. Dynamic water contact angle measurement indicated that the scaffold surface became more hydrophilic after the aminolytic treatment and the subsequent immobilization of the biomolecules. The appropriateness of these PCL fibrous scaffolds for the tissue/cell culture was evaluated in vitro with three different cell lines, e.g., mouse fibroblasts (L929), human epidermal keratinocytes (HEK001), and mouse calvaria-derived preosteoblastic cells (MC3T3-E1). Both the neat and the modified PCL fibrous scaffolds released no substances in the levels that were harmful to these! cells. Among the various biomolecule-immobilized PCL fibrous scaffolds, the ones that had been immobilized with type I collagen, a Arg-Gly-Asp-containing protein, showed the greatest ability to support both the attachment and the proliferation of all of the investigated cell types, followed by those that had been immobilized with GRGDS peptide. PMID: 20355894 [PubMed - in process] | | |
| Functional Assessment of Cross-Linked Porous Gelatin Hydrogels for Bioengineered Cell Sheet Carriers.
April 2, 2010 at 6:04 AM
|
| | Functional Assessment of Cross-Linked Porous Gelatin Hydrogels for Bioengineered Cell Sheet Carriers. Biomacromolecules. 2010 Mar 31; Authors: Lai JY, Li YT An efficient carrier for corneal endothelial cell therapy should deliver and retain the cell sheet transplants at the site of injury without causing adverse effects. Here we introduced a simple stirring process combined with freeze-drying (SFD1) method for the development of gelatin hydrogels with enlarged pore structure that can improve the aqueous humor circulation. Samples fabricated by air-drying (AD) or freeze-drying method were used for comparison. After cross-linking with 1 mM 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC), the discs were investigated to assess their functionality. The simultaneous presence of ice crystals and gas bubbles resulted in large pore size (461 +/- 85 mum) and high porosity (48.0 +/- 1.9%) of SFD1 carriers. Among all of the samples studied, the SFD1 hydrogels showed the most appropriate swelling characteristics without squeezing effect on the anterior segment tissues of the eye. The enlarged pore structure also allowed carr! iers to contain the highest fraction of mobile water and exhibit the lowest resistance to the glucose permeation. In comparison with AD samples, the SFD1 materials had better cytocompatibility and biocompatibility and more effectively prevented a drastic change of intraocular pressure. Rheological measurements showed that the SFD1 hydrogels behaved like an elastic solid and had a tough (rigid and deformable) texture. As a temporary supporter, the biodegradable gelatin hydrogel could facilitate cell sheet transfer and avoid long-term residence of foreign carriers in the body. Our findings suggest that the gelatin discs with enlarged pore structure have potential as cell sheet carriers for intraocular delivery and corneal tissue engineering. PMID: 20355704 [PubMed - as supplied by publisher] | | |
| Psychometric validation of the Manual Ability Measure-36 (MAM-36) in patients with neurologic and musculoskeletal disorders.
April 2, 2010 at 6:04 AM
|
| | Psychometric validation of the Manual Ability Measure-36 (MAM-36) in patients with neurologic and musculoskeletal disorders. Arch Phys Med Rehabil. 2010 Mar;91(3):414-20 Authors: Chen CC, Bode RK OBJECTIVES: To evaluate the psychometric properties of the Manual Ability Measure-36 (MAM-36), a new hand function outcome measure, and to examine differences in manual abilities and item parameters in patients with neurologic and musculoskeletal conditions. DESIGN: Convenience sample from 2 time periods, cross-sectional. SETTING: Outpatient rehabilitation units and private hand clinics. PARTICIPANTS: Patients (N=337; mean age, 50.3+/-14.9y) with a variety of neurologic and musculoskeletal (orthopedic) diagnoses. Most of these individuals were community dwelling, and all had residual functional limitations in the hand(s). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Rasch analysis was performed on MAM-36 data to evaluate both scale structure and psychometric properties, which include rating distribution, step measures, item fit, separation, and dimensionality. A t test was performed to examine the differences in manual abilities in patients with the 2 con! ditions. Uniform differential item functioning (DIF) between neurologic and musculoskeletal groups was examined. (DIF occurs when subgroup members within the sample with the same level of the underlying trait being measured respond differently to an individual item.) Manual ability estimates were recalibrated with step and common item anchoring; they were compared with those derived from the original analysis. RESULTS: The 36 items measured a single construct with no misfitting items. The scale was used as intended. The items can reliably separate the participants into 5 ability strata. Neurologic patients had a significantly lower mean manual ability than musculoskeletal patients. Fourteen items exhibited DIF. However, DIF had no effect on either scale quality or calibration of manual ability. We decided that a single rating scale is appropriate for both groups. CONCLUSIONS: This study showed that the MAM-36 has more than adequate psychometric properties and can be used as! a generic outcome measure for patients with a wide variety of! clinica l diagnoses. PMID: 20298833 [PubMed - indexed for MEDLINE] | | |
| In vivo monitoring of function of autologous engineered pulmonary valve.
April 2, 2010 at 6:04 AM
|
| | In vivo monitoring of function of autologous engineered pulmonary valve. J Thorac Cardiovasc Surg. 2010 Mar;139(3):723-31 Authors: Gottlieb D, Kunal T, Emani S, Aikawa E, Brown DW, Powell AJ, Nedder A, Engelmayr GC, Melero-Martin JM, Sacks MS, Mayer JE OBJECTIVES: Clinical translation of tissue-engineered heart valves requires valve competency and lack of stenosis in the short and long term. Early studies of engineered valves showed promise, although lacked complete definition of valve function. Building on prior experiments, we sought to define the in vivo changes in structure and function of autologous engineered pulmonary valved conduits. METHODS: Mesenchymal stem cells were isolated from neonatal sheep bone marrow and seeded onto a bioresorbable scaffold. After 4 weeks of culture, valved conduits were implanted. Valve function, cusp, and conduit dimensions were evaluated at implantation (echocardiography), at the experimental midpoint (magnetic resonance imaging), and at explant, at 1 day, and 1, 6, 12, or 20 weeks postoperatively (direct measurement, echocardiography). Histologic evaluation was performed. RESULTS: Nineteen animals underwent autologous tissue-engineered valved conduit replacement. At implant! ation, valved conduit function was excellent; maximum transvalvular pressure gradient by Doppler echocardiography was 17 mm Hg; most valved conduits showed trivial pulmonary regurgitation. At 6 postoperative weeks, valve cusps appeared less mobile; pulmonary regurgitation was mild to moderate. At 12 weeks or more, valved conduit cusps were increasingly attenuated and regurgitant. Valved conduit diameter remained unchanged over 20 weeks. Dimensional measurements by magnetic resonance imaging correlated with direct measurement at explant. CONCLUSIONS: We demonstrate autologous engineered tissue valved conduits that function well at implantation, with subsequent monitoring of dimensions and function in real time by magnetic resonance imaging. In vivo valves undergo structural and functional remodeling without stenosis, but with worsening pulmonary regurgitation after 6 weeks. Insights into mechanisms of in vivo remodeling are valuable for future iterations of engineered heart ! valves. PMID: 20176213 [PubMed - indexed for MEDLINE] | | |
| Hypoxia inducible factors in cancer stem cells.
April 2, 2010 at 6:04 AM
|
| | Hypoxia inducible factors in cancer stem cells. Br J Cancer. 2010 Mar 2;102(5):789-95 Authors: Heddleston JM, Li Z, Lathia JD, Bao S, Hjelmeland AB, Rich JN Oxygen is an essential regulator of cellular metabolism, survival, and proliferation. Cellular responses to oxygen levels are monitored, in part, by the transcriptional activity of the hypoxia inducible factors (HIFs). Under hypoxia, HIFs regulate a variety of pro-angiogenic and pro-glycolysis pathways. In solid cancers, regions of hypoxia are commonly present throughout the tissue because of the chaotic vascular architecture and regions of necrosis. In these regions, the hypoxic state fluctuates in a spatial and temporal manner. Transient hypoxic cycling causes an increase in the activity of the HIF proteins above what is typical for non-pathologic tissue. The extent of hypoxia strongly correlates to poor patient survival, therapeutic resistance and an aggressive tumour phenotype, but the full contribution of hypoxia and the HIFs to tumour biology is an area of active investigation. Recent reports link resistance to conventional therapies and the metastatic poten! tial to a stem-like tumour population, termed cancer stem cells (CSCs). We and others have shown that within brain tumours CSCs reside in two niches, a perivascular location and the surrounding necrotic tissue. Restricted oxygen conditions increase the CSC fraction and promote acquisition of a stem-like state. Cancer stem cells are critically dependant on the HIFs for survival, self-renewal, and tumour growth. These observations and those from normal stem cell biology provide a new mechanistic explanation for the contribution of hypoxia to malignancy. Further, the presence of hypoxia in tumours may present challenges for therapy because of the promotion of CSC phenotypes even upon successful killing of CSCs. The current experimental evidence suggests that CSCs are plastic cell states governed by microenvironmental conditions, such as hypoxia, that may be critical for the development of new therapies targeted to disrupt the microenvironment. PMID: 20104230 [PubMed - indexed for MEDLINE] | | |
| [Long-term observation of prefabricated urethra with buccal mucosa in expanded capsule]
April 2, 2010 at 6:04 AM
|
| | [Long-term observation of prefabricated urethra with buccal mucosa in expanded capsule] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Dec;23(12):1487-90 Authors: Li P, Cai M, Li Z, Zhan S, Jin H, Wang S, Wang Q, Xu L, Shi B OBJECTIVE: To investigate the histological and keratinous variation of prefabricated urethra in the capsule with micro-mucosa and gelatin sponge compound graft. METHODS: Five 8-week-old Guizhou miniature pigs (2 females and 3 males) weighing 20-25 kg were used. Eight tissue expanders were bilaterally inserted into subcutaneous position on the dorsal thorax of each pig. Forty inserted expanders were randomized into two groups (n=20 per group). For the experimental group, the free buccal mucosa was cut into particles less than 1 mm in diameter, spread onto the gelatin sponge (3 cm x 2 cm) and then transplanted to the capsule; the area expansion ratio of autogenous micro-mucosa was 8 : 1. For the control group, soft tissue expander without mucosa graft was implanted. The pressure in inserted expander was about 40 mm Hg (1 mm Hg=0.133 kPa). Inflation should be stopped when the injected saline volume reached 15 mL. The animals were killed 1 and 2 weeks and 1, 2, and 4 ! months after the implant to receive examination. Microscope, histology, and immunohistochemistry changes were observed. RESULTS: All the animals survived to the end of the experiment and the wounds healed by first intention. There was no obvious degeneration of gelatin sponge, and some of the mucosa survived 1 week after implant. The gelatin sponge was partly absorbed, most of the mucosa survived 2 weeks after implant. Visual examination showed complete epithelialization of the entire cavity 1 month after implant. The experimental group at 2 and 4 months were similar to that of at 1 month in gross observations. The neo-mucosa was not found in the control group at different time points after implant. Histology examination revealed that compound implant was mainly infiltrated by inflammatory cells and the micro-mucosa survived well 1 week after implant in the experimental group. The stratified squamous epithelium presented obvious polarity and the submucous neovascularization! was abundant 2 weeks after implant. The compound implant achi! eved com plete epithelialization 1 month after implant. The epithelium degeneration occurred 2 months after implant. The stratified squamous epithelium presented no abovious polarity 4 months after implant. No neo-mucosa was evident in control group at different time points. The experimental group was positive for the pan-cytokeratin staining at 1, 2 weeks, and 1, 2 months after implant, but negative at 4 months after implant. The pan-cytokeratin staining was negative in the control group at different time points. CONCLUSION: The buccal micromucosa and gelatin sponge compound graft can grow well on the expanded capsule 1 month after implant and the epithelium degeneration is evident 2 months after implant. Environment of implanted mucosa has great influence on epithelium mucosa. PMID: 20073316 [PubMed - indexed for MEDLINE] | | |
| Cellular therapy of kidney diseases.
April 2, 2010 at 6:04 AM
|
| | Cellular therapy of kidney diseases. Semin Dial. 2009 Nov-Dec;22(6):629-35 Authors: Imai N, Kaur T, Rosenberg ME, Gupta S The understanding of cellular sources of kidney regeneration has rapidly evolved in the last decade. It is now believed that regeneration occurs predominantly from cells that reside within the injured kidney, with minimal contribution from extra-renal cells. We now know that improved kidney regeneration seen following exogenous administration of stem cells occur predominantly by noncellular paracrine mechanisms. Of all extra-renal stem cells, mesenchymal stem cells (MSC) are the most promising stem cell type for treating kidney diseases. There is an ongoing clinical trial evaluating safety and efficacy of MSC in treating acute kidney injury (AKI). Results of this trial are expected to bring use of MSC closer to the clinical realm. An improved understanding of the small molecules that facilitate kidney regeneration and are secreted by MSC will likely result in the development of new therapies for treating AKI. Identification of adult stem cell markers will result i! n improved understanding of pathophysiology of kidney diseases and could lead to the development of new cellular therapies. Directed differentiation of stem cells into desired cell types such as erythropoietin producing cells will allow selective replacement of lost kidney function. Cell-based therapies for patients with chronic kidney disease are presently in proof-of-principle stage and are expected to evolve in the coming years with improved understanding of stem cell biology. Technological advancement in cellular therapy is expected to provide improved therapeutic options for patients with kidney diseases in the near future. PMID: 20017833 [PubMed - indexed for MEDLINE] | | |
| Electrophysiological properties of human induced pluripotent stem cells.
April 2, 2010 at 6:04 AM
|
| | Electrophysiological properties of human induced pluripotent stem cells. Am J Physiol Cell Physiol. 2010 Mar;298(3):C486-95 Authors: Jiang P, Rushing SN, Kong CW, Fu J, Lieu DK, Chan CW, Deng W, Li RA Human embryonic stem cells (hESCs) can self-renew while maintaining their pluripotency. Direct reprogramming of adult somatic cells to induced pluripotent stem cells (iPSCs) has been reported. Although hESCs and human iPSCs have been shown to share a number of similarities, such basic properties as the electrophysiology of iPSCs have not been explored. Previously, we reported that several specialized ion channels are functionally expressed in hESCs. Using transcriptomic analyses as a guide, we observed tetraethylammonium (TEA)-sensitive (IC(50) = 3.3 +/- 2.7 mM) delayed rectifier K(+) currents (I(KDR)) in 105 of 110 single iPSCs (15.4 +/- 0.9 pF). I(KDR) in iPSCs displayed a current density of 7.6 +/- 3.8 pA/pF at +40 mV. The voltage for 50% activation (V(1/2)) was -7.9 +/- 2.0 mV, slope factor k = 9.1 +/- 1.5. However, Ca(2+)-activated K(+) current (I(KCa)), hyperpolarization-activated pacemaker current (I(f)), and voltage-gated sodium channel (Na(V)) and voltage! -gated calcium channel (Ca(V)) currents could not be measured. TEA inhibited iPSC proliferation (EC(50) = 7.8 +/- 1.2 mM) and viability (EC(50) = 5.5 +/- 1.0 mM). By contrast, 4-aminopyridine (4-AP) inhibited viability (EC(50) = 4.5 +/- 0.5 mM) but had less effect on proliferation (EC(50) = 0.9 +/- 0.5 mM). Cell cycle analysis further revealed that K(+) channel blockers inhibited proliferation primarily by arresting the mitotic phase. TEA and 4-AP had no effect on iPSC differentiation as gauged by ability to form embryoid bodies and expression of germ layer markers after induction of differentiation. Neither iberiotoxin nor apamin had any function effects, consistent with the lack of I(KCa) in iPSCs. Our results reveal further differences and similarities between human iPSCs and hESCs. A better understanding of the basic biology of iPSCs may facilitate their ultimate clinical application. PMID: 19955484 [PubMed - indexed for MEDLINE] | | |
| Gene expression profile of mouse masseter muscle after repetitive electrical stimulation.
April 2, 2010 at 6:04 AM
|
| | Gene expression profile of mouse masseter muscle after repetitive electrical stimulation. J Prosthodont Res. 2010 Jan;54(1):36-41 Authors: Ono T, Maekawa K, Sonoyama W, Kojima S, Tanaka T, Clark GT, Kuboki T PURPOSE: To examine gene expression profile changes in the mouse masseter muscle tissue after repetitive electrical stimulation by using a DNA microarray technique. METHODS: Nine male ICR mice aged 10 weeks were used. Each anesthetized mouse was secured on a platform in a supine position and the masseter muscle tissues on both sides were exposed. Bipolar electrodes were set on the right masseteric fascia to electrically stimulate the masseter muscle (8 V, 10 Hz, 20 ms) for 30 min. After cessation of stimulation bilateral masseter muscle tissues were sampled at 0 h (n=3), 1h (n=3), 2h (n=3). Total RNA was isolated from the homogenized muscle tissues and purified mRNA samples (50 microg) were processed and hybridized with microarray slides. Probe arrays were then scanned and analyzed to calculate the signal density. Gene expression profiles were compared at each time point between the right (stimulation side) and left (control side) masseter. When the gene expressio! n levels were different more than 2-fold, the difference was regarded as positive. RESULTS: Of the 6400 genes assessed, 1733 genes were up-regulated and 515 genes were down-regulated in the stimulation side at least once during the experimental time course. These up- or down-regulated genes were associated with autoimmune/inflammatory disease (28/114), cardiovascular disease (17/61), neuroscience (12/50), apoptosis (27/93), diabetes/obesity (9/28), signal transduction (66/250) and others. 28 genes were up-regulated and 25 genes were down-regulated at all time points. CONCLUSIONS: Dramatic gene expression changes were induced by the repetitive electrical muscle stimulation in mouse masseter. PMID: 19819208 [PubMed - indexed for MEDLINE] | | |
| [Preparation and physicochemical property of carboxymethyl-chitosan/hyaluronic acid poly(vinyl alcohol) blend membrane]
April 2, 2010 at 6:04 AM
|
| | [Preparation and physicochemical property of carboxymethyl-chitosan/hyaluronic acid poly(vinyl alcohol) blend membrane] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Aug;23(8):1012-6 Authors: Liu W, Li S, Chang J, Han B, Liu W OBJECTIVE: To prepare carboxymethyl-chitosan/hyaluronic acid/poly(vinyl alcohol) (CHP) blend membrane, evaluate its physicochemical properties and intraocular biocompatibility and to investigate its feasibility to be applied to glaucoma filtering surgery. METHODS: CHP blend membrane was prepared using solution casting method after blending carboxymethyl-chitosan, HA and poly(vinyl alcohol) in a proportion of 5 : 4 : 1 (M/M). Its water absorption rate, swelling rate, permeability, and mechanical properties were detected. Subconjunctival fibroblasts separated from subconjunctival tissue of New Zealand white rabbits were cultured, and the cells at passage 4 were cultured on cell culture plate with or without the CHP blend membrane, serving as the experimental group and the control group, respectively. Effect of the CHP blend membrane on the subconjunctival fibroblasts was tested by MTT method 24, 48, and 72 hours after culture. Six New Zealand white rabbits were rand! omly divided into two groups (n = 3 rabbits per group), and the CHP blend membrane and SK gel were implanted into the rabbits' subconjunctival space and anterior chamber in the experimental group and the control group, respectively. Slit lamp observation and binocular reaction record were conducted 1, 3, 5, 9, 11, 20, 30, 45, and 60 days after operation. Corneal tissue harvested from the experimental group was observed using scanning electron microscope 15 days after operation to study ophthalmic biocompatibility and biodegradability. RESULTS: The water absorption rate and the swelling rate of the CHP blend membrane was 83.8% +/- 1.3% and 3.59 +/- 0.50, respectively. The tensile strength of the dry and the wet CHP blend membrane was (20.59 +/- 1.73) and (0.51 +/- 0.13) MPa, respectively. The breaking elongation rate of the dry and the wet CHP blend membrane was 10.69% +/- 1.16% and 53.15% +/- 2.46%, respectively. The CHP blend membrane had good permeability to NaCl and L-ty! rosine. Absorbance (A) value of the experimental group 24, 48,! and 72 hours after breeding was 0.207 +/- 0.083, 0.174 +/- 0.080, and 0.181 +/- 0.048, respectively, while the A value of the control group was 0.284 +/- 0.011, 0.272 +/- 0.083, and 0.307 +/- 0.056, respectively. Significant difference was evident between two groups (P < 0.05). In the experimental group, a small amount of floccus was exuded around the implanted membrane 1 day after operation; the floccus was absorbed on the third day, and there was no obvious inflammatory reaction occurring on the eleventh day. Most of the membrane degraded on the sixtieth day. Scanning electron microscope observation showed that the hexagonal morphology of the corneal endothelial cells was intact, and no degradation particles adhered to the surface. In the control group, the implantation of SK gel into anterior chamber was unsuccessful because the SK gel was quite soft and easily broken. In the experimental group, mild hyperemia emerged around the implanted membrane 1 day after the subconjuncti! val implantation of the membrane, and it became normal on the ninth day. No corneal edema and inflammatory reaction of anterior chamber occurred till the sixtieth day. The results in the control group and the experiment group were similar. CONCLUSION: Due to its good physicochemical properties and biocompatibility, the CHP blend membrane has potential applications in glaucoma filtering surgery. PMID: 19728624 [PubMed - indexed for MEDLINE] | | |
| [Preparation of three-dimensional porous scaffold of PLGA-silk fibroin-collagen nanofiber and its cytocompatibility study]
April 2, 2010 at 6:04 AM
|
| | [Preparation of three-dimensional porous scaffold of PLGA-silk fibroin-collagen nanofiber and its cytocompatibility study] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Aug;23(8):1007-11 Authors: Wu G, Dong C, Wang G, Gao W, Fan H, Xiao W, Zhang L OBJECTIVE: To develop three-dimensional (3D) porous nanofiber scaffold of PLGA-silk fibroin-collagen and to investigate its cytocompatibility in vitro. METHODS: Method of electrostatic spinning was used to prepare 3D porous nanofiber scaffold of PLGA-silk fibroin-collagen (the experimental group) and 3D porous nanofiber scaffold of PLGA (the control group). The scaffold in each group was observed by scanning electron microscope (SEM). The parameters of scaffold fiber diameter, porosity, water absorption rate, and tensile strength were detected. SC harvested from the bilateral brachial plexus and sciatic nerve of 8 SD suckling rats of inbred strains were cultured. SC purity was detected by S-100 immunohistochemistry staining. The SCs at passage 4 (5 x 10(4) cells/mL) were treated with the scaffold extract of each group at a concentration of 25%, 50%, and 100%, respectively; the cells treated with DMEM served as blank control group. MTT method was used to detect abs! orbance (A) value 1, 3, 5, and 7 days after culture. The SC at passage 4 were seeded on the scaffold of the experimental and the control group, respectively. SEM observation was conducted 2, 4, and 6 days after co-culture, and laser scanning confocal microscope (LSCM) observation was performed 4 days after co-culture for the growth condition of SC on the scaffold. RESULTS: SEM observation: the scaffold in two groups had interconnected porous network structure; the fiber diameter in the experimental and the control group was (141 +/- 9) nm and (205 +/- 11) nm, respectively; the pores in the scaffold were interconnected; the porosity was 87.4% +/- 1.1% and 85.3% +/- 1.3%, respectively; the water absorption rate was 2 647% +/- 172% and 2 593% +/- 161%, respectively; the tensile strength was (0.32 +/- 0.03) MPa and (0.28 +/- 0.04) MPa, respectively. S-100 immunohistochemistry staining showed that the SC purity was 96.5% +/- 1.3%. MTT detection: SC grew well in the different con! centration groups and the control group, the absorbance (A) va! lue incr eased over time, significant differences were noted among different time points in the same group (P < 0.05), and there was no significant difference between the different concentration groups and the blank control group at different time points (P > 0.05). SEM observation: in the experimental group, SC grew well on the scaffold, axon connection occurred 4 days after co-culture, the cells proliferated massively and secreted matrix 6 days after co-culture, and the growth condition of the cells was better than the control group. The condition observed by LSCM 4 days after co-culture was the same as that of SEM. CONCLUSION: The 3D porous nanofiber scaffold PLGA-silk fibroin-collagen prepared by the method of electrostatic spinning is safe, free of toxicity, and suitable for SC growth, and has good cytocompatibility and proper aperture and porosity. It is a potential scaffold carrier for tissue engineered nerve. PMID: 19728623 [PubMed - indexed for MEDLINE] | | |
| [Effects of platelet-rich plasma on BMSCs differentiation into SC in vitro]
April 2, 2010 at 6:04 AM
|
| | [Effects of platelet-rich plasma on BMSCs differentiation into SC in vitro] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Aug;23(8):997-1001 Authors: Xia C, Chen Y, Sun K, Tian S, Yang X, Hong G OBJECTIVE: To explore effect of platelet-rich plasma (PRP) on rabbit BMSCs differentiation into SC in vitro and to detect secretory function of the differentiated cells. METHODS: BMSCs isolated from 5 mL bone marrow of 2-month-old New Zealand white rabbit were cultured using density gradient centrifugation and adherence screening methods. A total of 5 mL femoral vein blood was obtained from rabbits to prepare PRP using modified Appel method. The BMSCs at passage 3 were divided into three groups: the combined induction group, in which the cells were cultured with complete medium containing PRP after beta-mercaptoethanol and retinoic acid inductions; the simple induction group, in which the cells were cultured with L-DMEM complete medium without PRP after beta -mercaptoethanol and retinoic acid induction; the control group, in which the cells were cultured with L-DMEM complete medium. Growth condition of the cells in each group was observed using inverted microscope! . cell identification was conducted at 4, 7, 9, and 11 days after culture using immunofluorescence staining method, and NGF content was detected by ELISA method. NGF mRNA expression was assayed by RT-PCR 11 days after culture. RESULTS: Most cells in the combined induction and the simple induction group were out of BMSCs typical cell morphology 4 days after culture; cells in the combined induction group were out of BMSCs typical cell morphology and changed into cells resembling SC in terms of morphology and contour 9 days after culture. The cells in the control group showed no obvious morphological changes. S-100 protein expression in the cells was evident in the combined induction and the simple induction group at each time point after induced culture; the positive expression rate of cell in each group was increased over time, and significant differences were evident between the combined induction group and the simple induction group 7, 9, and 11 days after culture (P < ! 0.05). Control group was negative for the expression. There we! re signi ficant differences when comparing the control group with the combined induction group or the simple induction group in terms of NGF content at each time point (P < 0.01). Significant difference was evident between the combined induction group and the simple induction group 7, 9, and 11 days after culture (P < 0.05), and no significant difference was noted 4 days after culture (P > 0.05). Relative intensity of NGF mRNA expression in the combined induction group was greater than that of the simple induction group 11 days after culture (P < 0.05). CONCLUSION: Rabbit BMSCs can differentiate into SC excreting NGF under certain induction condition in vitro. PRP can remarkably promote BMSCs differentiation into SC. PMID: 19728621 [PubMed - indexed for MEDLINE] | | |
| [Primary culture of sinoatrial node cells from suckling pigs and its co-culture with Col I fiber scaffold]
April 2, 2010 at 6:04 AM
|
| | [Primary culture of sinoatrial node cells from suckling pigs and its co-culture with Col I fiber scaffold] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Aug;23(8):980-4 Authors: Wan J, Zhong X, Liao B, Wang M, Deng M OBJECTIVE: To locate sinoatrial node (SAN) in suckling pigs, to develop a reliable method for isolation, purification and cultivation of SAN cells and to observe the compatibility of SAN cells and Col I fiber scaffold. METHODS: Five newborn purebred ChangBaiShan suckling pigs (male and female), aged less than 1-day-old and weighing 0.45-0.55 kg, were used. Multi-channels electrophysiological recorder was applied to detect the original site of atrial waves. Primary SAN cells harvested from that area were cultured by the conventional culture method and the purification culture method including differential velocity adherent technique and 5-BrdU treatment, respectively. Atrial myocytes isolated from the left atrium underwent purified culture. Cell morphology, time of cell attachment, time of unicellular pulsation, and pulsation frequency were observed using inverted microscope. The purified cultured SAN cells (5 x 10(5) cells/mL) were co-cultured with pre-wetted Col ! I fiber scaffold for 5 days, and then the cells were observed by HE staining and scanning electron microscope (SEM). RESULTS: The atrial waves occurred firstly at the area of SAN. The purified cultured SAN cells were spindle, triangular, and irregular in morphology, and the spindle cells comprised the greatest proportion. Atrial myocytes were not spindle-shaped, but primarily triangular and irregular. The proportion of spindle cells in the conventional cultured SAN cells was decreased from 73.0% +/- 2.9% in the purified cultured SAN cells, to 44.7% +/- 2.3% (P < 0.01), and the proportion of irregular cells increased from 7.0% +/- 1.7% in the purified cultured SAN cells to 36.1% +/- 2.6% (P < 0.01) . The proportion of the triangular cells in the purified and the conventional cultured SAN cells was 20.0% +/- 2.1% and 19.2% +/- 2.5%, respectively (P > 0.05). At 5 days after co-culture, HE staining displayed lots of SAN cells in Col I fiber scaffold, and SEM demonstrat! ed conglobata adherence of the cells to the surface and latera! l pore w all of scaffold, mutual connections of the cell processes, or attachment of cells to lateral pore wall of scaffold through pseudopodia. CONCLUSION: With accurate SAN location, the purification culture method containing differential velocity adherent technique and 5-BrdU treatment can increase the proportion of spindle cells and is a reliable method for the purification and cultivation of SAN cells. The SAN cells and Col I fiber scaffold have a good cellular compatibility. PMID: 19728618 [PubMed - indexed for MEDLINE] | | |
| [Experimental study of repairing full-thickness articular cartilage defect with chondrocyte-sodium alginate hydrogel-SIS complex]
April 2, 2010 at 6:04 AM
|
| | [Experimental study of repairing full-thickness articular cartilage defect with chondrocyte-sodium alginate hydrogel-SIS complex] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Aug;23(8):974-9 Authors: Mo X, Deng L, Li X, Xie H, Luo J, Guo S, Yang Z OBJECTIVE: To explore the effect of tissue engineered cartilage reconstructed by using sodium alginate hydrogel and SIS complex as scaffold material and chondrocyte as seed cell on the repair of full-thickness articular cartilage defects. METHODS: SIS was prepared by custom-made machine and detergent-enzyme treatment. Full-thickness articular cartilage of loading surface of the humeral head and the femoral condyle obtained from 8 New Zealand white rabbits (2-3 weeks old) was used to culture chondrocytes in vitro. Rabbit chondrocytes at passage 4 cultured by conventional multiplication method were diluted by sodium alginate to (5-7) x 10(7) cells/mL, and then were coated on SIS to prepare chondrocyte-sodium alginate hydrogel-SIS complex. Forty 6-month-old clean grade New Zealand white rabbits weighing 3.0-3.5 kg were randomized into two groups according to different operative methods (n = 20 rabbits per group), and full-thickness cartilage defect model of the unila! teral knee joint (right or left) was established in every rabbit. In experimental group, the complex was implanted into the defect layer by layer to construct tissue engineered cartilage, and SIS membrane was coated on the surface to fill the defect completely. While in control group, the cartilage defect was filled by sodium alginate hydrogel and was sutured after being coated with SIS membrane without seeding of chondrocyte. General condition of the rabbits after operation was observed. The rabbits in two groups were killed 1, 3, 5, 7, and 9 months after operation, and underwent gross and histology observation. RESULTS: Eight rabbits were excluded due to anesthesia death, wound infection and diarrhea death. Sixteen rabbits per group were included in the experiment, and 3, 3, 3, 3, and 4 rabbits from each group were randomly selected and killed 1, 3, 5, 7, and 9 months after operation, respectively. Gross observation and histology Masson trichrome staining: in the experime! ntal group, SIS on the surface of the implant was fused with t! he host tissue, and the interface between them disappeared 1 month after operation; part of the implant was chondrified and the interface between the implant and the host tissue was fused 3 months after operation; the implant turned into fibrocartilage 5 months after operation; fiber arrangement of the cartilage in the implant was close to that of the host tissue 7 months after operation; cartilage fiber in the implant arranged disorderly and active cell metabolism and proliferation were evident 9 months after operation. While in the control group, no repair of the defect was observed 9 months after operation. No obvious repair was evident in the defects of the control group within 9 months after operation. Histomorphometric evaluation demonstrated that the staining intensity per unit area of the reparative tissue in the defect of the experimental group was significant higher than that of the control group at each time point (P < 0.05), the chondrification in the experimental gro! up was increased gradually within 3, 5, and 7 months after operation (P < 0.05), and it was decreased 9 months after operation comparing with the value at 7 months after operation (P < 0.05). CONCLUSION: Constructed by chondrocyte-sodium alginate hydrogel-SIS in complex with surficial suturing of SIS membrane, the tissue engineered cartilage can in-situ repair cartilage defect, promote the regeneration of cartilage tissue, and is in line with physiological repair process of articular cartilage. PMID: 19728617 [PubMed - indexed for MEDLINE] | | |
| [Advances of nucleus pulposus cells for treating intervertebral disc degeneration]
April 2, 2010 at 6:04 AM
|
| | [Advances of nucleus pulposus cells for treating intervertebral disc degeneration] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Jul;23(7):864-7 Authors: Wang F, Wang Y, Wu X OBJECTIVE: To introduce the research of nucleus pulposus cells for treating intervertebral disc degeneration. METHODS: The original articles in recent years about nucleus pulposus cells for treating intervertebral disc degeneration were extensively reviewed, and retrospective and comprehensive analysis was performed. RESULTS: Nucleus pulposus cells are not only simply a remnant of embryonic notochordal cells, but have also an important influence on the well-being of the whole disc. The biological treatment strategies aim to regenerate the disc by either trying to improve the micro-environment within the disc or to increase the population of the nucleus pulposus, which includes transplanting mesenchymal stem cells to differentiate into nucleus-like cells in the degenerated intervertebral disc. CONCLUSION: Nucleus pulposus cells or nucleus pulposus like cells based cell transplantation methods prove to be a promising and realistic approach for the intervertebral dis! c regeneration. PMID: 19662995 [PubMed - indexed for MEDLINE] | | |
| [Analysis of hBMSCs spatial distribution and gene expression in biocoral scaffold with different seeding methods]
April 2, 2010 at 6:04 AM
|
| | [Analysis of hBMSCs spatial distribution and gene expression in biocoral scaffold with different seeding methods] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Jul;23(7):845-50 Authors: Zhu H, Sun L, Chen J, Wang H OBJECTIVE: To compare the effect of two different methods of cell seeding on spatial distribution and gene expression of hBMSCs in biocoral scaffold in vitro cultures. METHODS: The composite of hBMSCs and biocoral scaffold was prepared by traditional seeding (group A) and fibrin glue seeding (group B). The seeding efficiency was measured after 30 minutes of incubation in group B and after 3 hours in group A. At 2, 7, 14 and 21 days after culture, the samples were harvested and the serial longitudinal sections were cut for each embedded composite. The sections were stained with DAPI and were measured using fluorescence microscope with apostome under serial optical sections. The cell number in every 10 x objective field was automatically measured by AxioVision image analysis software and levels (from seeding surface to bottom L1-L5) or columns (from centre to margin) for comparing cell distribution were set up. The specific osteogenic genes [osteonectin (ON), core b! inding factor alpha1 (Cbfalpha1), osteocalcin (OC)] expression was measured by RT-PCR. RESULTS: The seeding efficiency was significantly higher in group B (88.32% +/- 4.2%) than in group A (66.51% +/- 12.33%, P < 0.01). At 2 days after culture, the cell number from L1 to L4 decreased gradully in two groups (P < 0.05); in the cell number of different columns, there was no significant difference in group A (P > 0.05) whereas significant difference in group B (P < 0.05); there was no significant difference in gene expression between two groups (P > 0.05). At 7 days after culture, the cell number was less than that at 2 days in group A and there was significant difference among levels (P < 0.05). The cell number and osteogenic gene expression increased sharply and there appeared uniform cell distribution in group B (P > 0.05). The gene expression of ON and Cbfalpha1 in group B was higher than that in group A (P < 0.05). At 14 days after culture, the cell! number in levels or columns in group A decreased sharply and ! was less than that at 7 days (P < 0.05); whereas the cell number was similar to that at 7 days in group B (P > 0.05). The OC gene expression reached the highest level in group B at 14 days. The gene expression was higher in group B than in group A (P < 0.05). At 21 days after culture, there was significant difference in the cell number among levels and in the gene expression between group A and group B (P < 0.05); there was no significant difference in the cell number among columns in two groups (P > 0.05). In addition, the cell number of most levels and columns in group B was more than that in group A at 7, 14 and 21 days after culture (P < 0.05). CONCLUSION: More uniform cell distribution with rapid proliferation and osteogenic differentiation is available in different levels or columns of scaffold by fibrin glue seeding than by traditional seeding. PMID: 19662991 [PubMed - indexed for MEDLINE] | | |
| [Effects of fibrin gels on cell proliferation and differentiation in MC3T3E1 cell line]
April 2, 2010 at 6:04 AM
|
| | [Effects of fibrin gels on cell proliferation and differentiation in MC3T3E1 cell line] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Jul;23(7):840-4 Authors: Chen L, Mai X, Zha LG, Wang Y, Chen X OBJECTIVE: To analyze MC3T3E1 cell morphology, proliferation, and osteogenic differentiation in fibrin gel (FG) so as to lay a fundament for use of FG in tissue engneering. METHODS: MC3T3E1 cells were incubated in three concentrations (20, 10 and 5 mg/mL)of FG as the experimental groups (groups A, B and C) and in the common medium culture as the control group (group D). The cell morphology and distribution in FG were observed by inverted phase contrast microscope and confocal laser scanning microscope at different time. The cell proliferation was assessed by fluorospectrophotometer. The alkaline phosphatase (ALP) activity was detected by automatic biochemistry analyses and von Kossa staining was used to analyze calcium salts mineralization. RT-PCR was used to analyze the ALP and bone sialoprotein (BSP) mRNA expression at 14 and 21 days. RESULTS: In groups A, B and C, the MC3T3E1 cells had long processes which connected each other and formed network; but fusiform o! r cube cells were observed in group D at 21 days. The fluorescence intensity was increased gradually with time, was the highest at 14 days and the lowest at 28 days in group D; it was highest in groups A, B and C at 28 days, there were statistically significant differences when compared with group D (P < 0.05). The ALP activity was increased gradually with time, and it was the highest at 28 days in group D and at 21 days in groups A and B, there were significant differences (P < 0.05), no statistically significant differences compared with group D at other time points (P > 0.05). The mineralization nodes were seen at 21 and 28 days in group A, but no mineralization nodes was seen in group D at 28 days. The RT-PCR results showed the mRNA expressions of ALP and BSP were enhanced in group A when compared with group D (P < 0.05). CONCLUSION: The osteogenic differentiation was most obvious and cell proliferation was most active after 21 days of incubation in FG. PMID: 19662990 [PubMed - indexed for MEDLINE] | | |
| [Optimal method for rat skeletal muscle decellularization]
April 2, 2010 at 6:04 AM
|
| | [Optimal method for rat skeletal muscle decellularization] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Jul;23(7):836-9 Authors: Qing Q, Qin T OBJECTIVE: To investigate an optimal method for SD rat skeletal muscle decellularization. METHODS: Sixteen SD rats (male and female) weighing 180-200 g were used. Thirty-six skeletal muscle bundles obtained from 10 rats were randomly divided into 3 groups: normal group (group A, n=4) received non-decellularization; time group (group T, n=16) and concentration group (group C, n=16) underwent decellularization using hypotonic-detergent method. Concentration of sodium dodecyl sulfate (SDS) was 1.0% for T group, which was subdivided into groups T1, T2, T3 and T4 (n=4 per subgroup) according to different processing durations (24, 48, 72 and 96 hours). Group C was treated for 48 hours and subdivided into groups C1, C2, C3 and C4 (n=4 per subgroup) according to different SDS concentrations (0.5%, 1.0%, 1.5% and 2.0%). The muscle bundles of each group underwent HE staining observation and hydroxyproline content detection in order to get the optimal decellularization condi! tion. Seven of 14 complete skeletal muscle bundles obtained from 6 SD rats were treated with the optimal decellularization condition (experimental group), and the rest 7 muscle bundles served as normal control (control group). The muscle bundles of each group were evaluated with gross observation, Masson staining and biomechanical test. RESULTS: HE staining: there was no significant difference between groups T1, T2, C1, C2 and C3 and group A in terms of muscle fiber; portion of muscle fibers in group C4 were removed; muscle fibers in group T3 were fully removed with a complete basement membrane structure; muscle fibers of group T4 were fully removed, and the structure of basement membrane was partly damaged. Hydroxyproline content detection: there was no significant difference between group A and groups C1, C2, C3, T1 and T2 (P > 0.05); significant difference was evident between group A and groups C4, T3 and T4 (P < 0.05); the difference between group C4 and groups T3! and T4 was significant (P < 0.05); no significant differen! ce was e vident between group T3 and group T4 (P > 0.05). The optimal decellularization condition was 4 degrees C, 1.0% SDS and 72 hours according to the results of HE staining and hydroxyproline content detection. Gross observation: the muscle bundles of the experimental group were pallid, half-transparent and fluffier comparing with the control group. Masson staining observation: the collagen fibers of the experimental group had a good continuity, and were fluffier comparing with control group. Biomechanics test: the maximum breaking load of the experimental group and the control group was (1.38 +/- 0.35) N and (1.98 +/- 0.77) N, respectively; the maximum extension displacement of the experimental group and the control group was (3.19 +/- 3.23) mm and (3.56 +/- 2.17) mm, respectively; there were no significant differences between two groups (P > 0.05). CONCLUSION: Acellular matrix with intact ECM and complete removal of muscle fibers can be obtained by oscillatory treatment o! f rat skeletal muscle at 4 degrees C with 1% SDS for 72 hours. PMID: 19662989 [PubMed - indexed for MEDLINE] | | |
| [Effect of copper-ion on proliferation and differentiation of vascular endothelial cells]
April 2, 2010 at 6:04 AM
|
| | [Effect of copper-ion on proliferation and differentiation of vascular endothelial cells] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Jul;23(7):832-5 Authors: Luo K, Fan Z, Feng Z, Li S, Chen X, Xie H OBJECTIVE: To evaluate the effect of copper-ion on the proliferation and differentiation of human umbilical vein endothelial cell (HUVEC). METHODS: HUVEC were cultured and passaged in vitro. HUVEC were inoculated into 96-well plate with density of 5 x 10(3)/well. All the cells were divided into 3 groups randomly according to different culture mediums: group A (5 micromol/L CuSO4), group B (25 micromol/L CuSO4), group C (control group). Every group had 4 wells, and the basic culture medium was MCDB131. The cell growth curves of 3 groups were drawn by using MTT. HUVEC were inoculated into 6-well plate with density of 2 x 10(5)/well. Grouping of the cells was the same as the above. The gene expressions of endothelial nitric oxide synthase (eNOS) and tyrosine kinase with immunoglobulin-like and EGF-like domain 1 (Tie-1) were detected by real-time RT-PCR. RESULTS: The growth curves revealed that the exponential growth time was the first 3 days, plateau growth time begu! n on the 4th day. The proliferation of group A was stronger than that of groups B and C from the 3rd day, within 2 days, the proliferation of group B was stronger than that of group C; however, it decreased and was weaker than group C from the 4th day, all showing statistically significant difference (P < 0.05). The results of real-time RT-PCR revealed that the expressions of eNOS in groups A, B and C were 7.294 +/- 1.488, 0.149 +/- 0.044 and 1.000 +/- 0.253; and the expressions of Tie-1 in groups A, B and C were 1.481 +/- 0.137, 1.131 +/- 0.191 and 1.000 +/- 0.177. Group A compared with groups B and C, both of 2 genes were up-regulated (P < 0.05). Group B compared with group C, eNOS was down-regulated (P < 0.05) and the difference of Tie-1 expression was not statistically significant (P > 0.05). CONCLUSION: 5 micromol/L copper-ion can promote the proliferation and differentiation of HUVEC effectively. PMID: 19662988 [PubMed - indexed for MEDLINE] | | |
| [Cytocompatibility study of Arg-Gly-Asp-recombinant spider silk protein/poly vinyl alcohol scaffold]
April 2, 2010 at 6:04 AM
|
| | [Cytocompatibility study of Arg-Gly-Asp-recombinant spider silk protein/poly vinyl alcohol scaffold] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Jun;23(6):747-50 Authors: Wang H, Wei M, Xue Z, Li M OBJECTIVE: To evaluate the cytocompatibility of Arg-Gly-Asp-recombinant spider silk protein (pNSR16)/ poly vinyl alcohol (PVA) through in vitro cytotoxicity experiment and cell-material co-culture experiment. METHODS: pNSR16/PVA scaffold and its extraction were prepared by using solvent casting/particulate leaching method, and NIH-3T3 cells were cultivated with the extraction in vitro. The cytotoxicity of scaffold was analyzed using MTT assay 1, 3 and 5 days after culture. Scanning electron microscope and HE staining observation were conducted 2, 4 and 6 days after culturing NIH-3T3 cells on the pNSR16/PVA scaffold. Immunohistochemistry detection was performed 6 days after co-culture. Adhesion, growth and expression of the cells on the scaffold were observed. RESULTS: The cytotoxicity of pNSR16/PVA scaffold was in grade 0. Scanning electron microscope observation: the cells covered the surface of the scaffold and were arranged in a directional manner 4 days after ! co-culture. HE staining: the cells adhered to and grew on the surface of scaffold, and migrated into the scaffold with the increase of culture duration. Immunohistochemistry detection: bFGF was secreted by NIH-3T3 cells, and the cells differentiated normally. CONCLUSION: pNSR16/PVA scaffold has a satisfactory cytocompatibility and may be an ideal tissue engineered scaffold material. PMID: 19594027 [PubMed - indexed for MEDLINE] | | |
| [Induction of axial vascularization in processed bovine cancellous bone scaffold using arteriovenous loop]
April 2, 2010 at 6:04 AM
|
| | [Induction of axial vascularization in processed bovine cancellous bone scaffold using arteriovenous loop] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Jun;23(6):694-7 Authors: Wang F, Liu J, Zhao G, Meng G OBJECTIVE: To explore the method of inducing axial vascularization in a processed bovine cancellous bone scaffold by using an arteriovenous loop, and to evaluate its effect of vascularization. METHODS: Custom-made processed bovine cancellous bone discs were processed into cylinder with circular grooves. Thirty male SD rats weighing 300-350 g (3-4 months old) were randomly divided into 2 groups (n = 15 per group): experimental group in which the femoral veins in the groin of rats were separated and transplanted to the contralateral femoral artery and vein stump, the processed bovine cancellous bone scaffold was inserted into the arteriovenous loop, which was placed into the annular groove. Control group, in which the blood vessels in the groin of rats were cut, no anastomosis was conducted, and the processed bovine cancellous bone scaffold was planted. At 2, 4 and 8 weeks after operation, gross observation, ink infusion histology observation and microvessel bulk de! nsity detection were conducted. RESULTS: At each postoperative time point, the samples in the experimental group were fresh red, the circulation of blood vessels were smooth bidirectionally, while the samples in the control group were dark red soft, and flexible. Ink infusion histology observation showed the processed bovine cancellous bone scaffold in the experimental group had obvious vascularization, the blood vessels tended to be mature and integrated into network, and neovascular sprouts originated from arteriovenous loop were evident, especially at 8 weeks after operation; while there was no vascularization in the control group. At 2, 4 and 8 weeks after operation, the bulk density of the microvessels in the experimental group was (3.59 +/- 1.84), (16.61 +/- 10.23) and (39.04 +/- 13.46) microm3/microm3, respectively, and it was (2.43 +/- 0.97), (6.79 +/- 2.92) and (25.31 +/- 10.98) microm3/microm3, respectively, in the control group. Significant differences was noted ! between two groups at 4 and 8 weeks after operation (P < 0.! 05), and no significant difference was evident at 2 weeks after operation (P > 0.05). CONCLUSION: Inducing vascularization in a processed bovine cancellous bone using an arteriovenous loop is a new strategy of revascularization and may provide valuable clues for the preparation of functional artificial bone. PMID: 19594016 [PubMed - indexed for MEDLINE] | | |
| [Effect of raloxifene on fracture healing of rabbits]
April 2, 2010 at 6:04 AM
|
| | [Effect of raloxifene on fracture healing of rabbits] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Jun;23(6):683-9 Authors: Li Z, Zheng H, Li X, Weng L, Lu X, Li L, Zhong Y, Deng L OBJECTIVE: To detect the influence of raloxifene (RLX) on fracture healing in rabbit. METHODS: Eight healthy New Zealand white rabbits (44 females and 36 males) weighing 1.9-2.1 kg were used. A 0.5-cm bone defect model in the mid-diaphysis of the left forelimb radius was established in 72 rabbits, which thereafter were divided into 4 groups (n = 18 per group, 10 females and 8 males): groups A, B and C received 7.5, 15.0 and 30.0 mg/(kg x d) RLX, respectively, from the 2nd to the 50th postoperative day; group D received no further treatment. The rest untreated 8 rabbits (4 females and 4 males) served as normal control for serum osteocalcin detection. At different postoperative time points, bone mineral density detection, X-ray scanning, biomechanics measurement, histology and immunohistochemistry observations were conducted; serum estradiol, plasma cholesterol, serum osteocalcin and the ratio of uterine weight to body weight were detected. RESULTS: The bone mineral! density of each group reached a peak 20 days after operation, showing a significant difference between groups A, B and C and group D (P < 0.05), and no significant differences among groups A, B and C (P > 0.05). On the 30th and 50th postoperative day, the maximum failure load and the maximum displacement of groups A, B and C were greater than those of group D (P < 0.05), but no significant differences among groups A, B and C were evident (P > 0.05). On the 7th, 20th and 30th postoperative day, the X-ray score of fracture healing of groups A, B and C was greater than group D (P < 0.05); on the 50th postoperative day, there was significant difference between groups B and C and group D, and between group A and group C (P < 0.05), and no significant difference was evident between group B and group C (P > 0.05). The percentage of new bone formation in the fractured area of groups A, B and C was greater than that of group D on the 30th and 50th postoperative! day (P < 0.05). For the type II collagen protein secretion! in the fractured area, groups B and C were superior to group D on the 30th postoperative day (P < 0.05), and there was no significant difference between group A and group D (P > 0.05); no significant differences among four groups were evident on the 50th postoperative day (P > 0.05). On the 10th, 30th and 50th postoperative day, the serum osteocalcin of groups A, B, C and D was higher than that of normal control (P < 0.05), groups B and C were higher than group D (P < 0.05), and there was no significant difference between groups A, B and C, and between group A and group D (P > 0.05). For the plasma cholesterol, on the 30th postoperative day, no significant change was detected in each group (P > 0.05); on the 50th postoperative day, obvious decrease was observed in groups A, B and C, showing a significant difference compared with group D (P < 0.05). On the 30th and 50th postoperative day, there was significant difference between groups B and C and group D in ! serum estradiol (P < 0.05), and no significant differences were evident among other groups (P > 0.05). On the 30th and 50th postoperative day, the ratio of uterine weight to body weight in groups B and C was less than that of group D (P < 0.05), and no significant difference was evident between group A and group C (P > 0.05). CONCLUSION: Oral administration of 7.5 mg/(kg x d) RLX can promote the fracture healing of rabbit radius defect models safely and effectively. PMID: 19594014 [PubMed - indexed for MEDLINE] | | |
| [Effects of epithelial cell conditioned medium on differentiation of BMSCs]
April 2, 2010 at 6:04 AM
|
| | [Effects of epithelial cell conditioned medium on differentiation of BMSCs] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 May;23(5):612-6 Authors: Yang P, Wei R, Tan B, Li X, Wang J, Zhou K, Zuo X, Li S, Xie H OBJECTIVE: To investigate the feasibility of inducing canine BMSCs to differentiate into epithelial cells in vitro with epithelial cell conditioned medium (ECCM). METHODS: Five mL BMSCs were obtained from iliac spine of a healthy adult male canine with weighing 10 kg, and then isolated and cultured. The oral mucosa was harvested and cut into 4 mm x 4 mm after the submucosa tissue was eliminated; ECCM was prepared. BMSCs of the 2nd passage were cultured and divided into two groups, cultured in ECCM as experimental group and in L-DMEM as control group. The cell morphological characteristics were observed and the cell growth curves of two groups were drawn by the continual cell counting. The cells were identified by immunohistochemical staining through detecting cytokeratin 19 (CK-19) and anti-cytokeratin AE1/AE3 on the 21st day of induction. The ultra-structure characteristics were observed under transmission electron microscope. RESULTS: The cells of two groups sho! wed long-fusiform in shape and distributed uniformly under inverted phase contrast microscope. The cell growth curves of two groups presented S type. The cell growth curve of the experimental group was right shifted, showing cell proliferation inhibition in ECCM. The result of immunohistochemical staining for CK-19 and anti-cytokeratin AE1/AE3 was positive in the experimental group, confirming the epithelial phenotype of the cells; while the result was negative in the control group. The cells were characterized by tight junction under transmission electron microscope. CONCLUSION: The canine ECCM can induce allogenic BMSCs to differentiate into epithelial cells in vitro. PMID: 19514588 [PubMed - indexed for MEDLINE] | | |
| [Effects of demineralized bone matrix modified with type II cadherin ectodomain on adhesion and osteogenic differentiation of BMSCs]
April 2, 2010 at 6:04 AM
|
| | [Effects of demineralized bone matrix modified with type II cadherin ectodomain on adhesion and osteogenic differentiation of BMSCs] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 May;23(5):602-6 Authors: Xiang Q, Deng C, Zhang Y, Zhang C, Zhou Y OBJECTIVE; To evaluate the adhesion, proliferation and osteogenic differentiation of rabbit BMSCs after cultured on freeze-dried demineralized bone matrix (FDBM) modified with type II cadherin ectodomain (Cad-II). METHODS: BMSCs isolated from 10 Japanese white rabbits (male and female, 4-week-old, 0.61-0.88 kg) were cultured. The second generation of BMSCs (cell density 1 x 10(6)/mL) were seeded onto the Cad-II modified allogenic FDBM (experimental group) and only FDBM (control group) respectively, and then cocultured in vitro. The densities of seeded cells, the adhesion rate and their ALP activity were measured. The complex was observed through inverted phase contrast microscope and scanning electron microscope to evaluate the interaction between cells and FDBM. Another group of second generation of BMSCs (cell density 5 x 10(5)/mL) were seeded onto the Cad-II modified FDBM (experimental group) and only FDBM (control group) respectively, and then cocultured in vi! tro too. The ALP activity and osteocalcin immunohistochemical was measured. RESULTS: There was no significant difference in cell proliferation between experimental group and control group. The adhesion rate of cells in the experimental group was 87.41% +/- 5.19%, higher than that in the the control group 35.56% +/- 1.75% (P < 0.01); the densities of seeded cells reached 5.0 x 10(5), showing significant difference compared with the control group (2.6 x 10(4), P < 0.05). Inverted phase contrast microscope showed that in the experimental group, more cultured BMSCs pasted in the hole and edge of the scaffold than that in the control group. HE staining showed the densities of seeded cells in the experimental group was higher than that in the control group. Scanning electron microscope showed that in the experimental group, a lot of cultured BMSCs adhered, spreaded in the scaffold, in the control group only a few BMSCs unevenly distributed in the scaffold. After 7 days of c! ulture, the cultured BMSCs on modified FDBM expressed higher A! LP activ ity; after 14 days of culture, the ALP activity (29.33 +/- 1.53) was higher than that cultured on unmodified FDBM (18.31 +/- 1.32), the positive rates of osteocalcin were 83% +/- 7% in the experimental group and 56% +/- 7% in the control group, showing significant difference (P < 0.01). CONCLUSION: Cad-II enhanced cell adhesion to FDBM and promoted BMSCs differentiate to osteoblast, but no obvious effects were observed in cell proliferation. PMID: 19514586 [PubMed - indexed for MEDLINE] | | |
| [Preliminary study on biological printing of hBMSCs]
April 2, 2010 at 6:04 AM
|
| | [Preliminary study on biological printing of hBMSCs] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Apr;23(4):497-500 Authors: Ma S, Chai G, Liu Q, Hu Q, Zhou G, Cui L OBJECTIVE: To establish a two-dimensional biological printing technique of hBMSCs so as to control the cell transfer process and keep cell viability after printing. METHODS: Bone marrow (5 mL) was obtained from healthy volunteer. The hBMSCs were regularly subcultured to harvest cells at passage 2, which were adjusted to the single cell suspension at a density of 1 x 10(6)/mL. The experiment was divided into 3 groups: printing group 1 in which cells underwent propidium iodide (PI) fluorescent labeling, then were transferred by rapid prototype biological printer (interval in x-axis 300 microm, interval in y-axis 1500 microm), and laser scanning confocal microscope was applied to observe cell fluorescence; printing group 2 in which cells received no PI labeling and were cultured for 2 hours after transfer, Live/Dead viability Kit was adopted to detect cell viability and laser scanning confocal microscope was applied to observe cell fluorescence; half of the cells in ! printing group receiving no Live/Dead viability Kit detection were cultured for 7 days, then inverted microscope was used to observe cell morphology, routine culture was conducted after the adherence of cells, the growth condition of cells was observed dynamically; control group in which steps were the same as the printing group 2 except that cell suspension received no printing. RESULTS: Laser scanning confocal microscope observation on the cells in printing group 1 revealed the "cell ink droplets" were distributed regularly and evenly in the two-dimensional layer and each contained 15-35 cells, meeting the requirement of designing two-dimensional cell printing. The cells in printing group 2 went through cell viability test, laser scanning confocal microscope observation showed the fluorescence of cells 30 minutes after cell incubation. There was no significant difference between the control group and the printing groups in terms of cell viability. The printed cells presen! ted normal adherence, good morphology and good growth state 7 ! days aft er routine culture. CONCLUSION: Biological printing technique can realize the oriented, quantificational and regular distribution of hBMSCs in the two-dimensional plane and lays the foundation for the construction of three-dimensional cell printing or even organ printing system. PMID: 19431994 [PubMed - indexed for MEDLINE] | | |
| [Experimental study on chondrogenic differentiation of rabbit adipose-derived stem cells treated with growth differentiation factor 5]
April 2, 2010 at 6:04 AM
|
| | [Experimental study on chondrogenic differentiation of rabbit adipose-derived stem cells treated with growth differentiation factor 5] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Apr;23(4):483-9 Authors: Liu Z, Jia C, Han C OBJECTIVE: To investigate the feasibility and effect of inducing adipose-derived stem cells (ADSCs) treated with growth differentiation factor 5 (GDF-5) to undergo chondrogenic differentiation in vitro. METHODS: Six healthy Japanese rabbits aged 3 months (2-3 kg) of clean grade were chosen, irrespective of sex. ADSCs were isolated and cultured with collagenase digestion, then were detected and identified by vimentin immunohistochemistry and CD44, CD49d, CD106 immunofluorescence staining. ADSCs at passage 3 were used and the cell density was adjusted to 1 x 10(6)/mL, then the ADSCs were treated with 0, 10, 100 ng/mL GDF-5 and common cultural medium, respectively. The morphology changes of the induced ADSCs were observed by inverted contrast phase microscope and their growth state were detected by MTT. The mRNA quantities of Col II and proteoglycan expressed by the induced ADSCs were detected with RT-PCR. The Col II proteoglycan synthesized by the induced ADSCs were! detected with alcian blue staining, toluidine blue staining, immunohistochemistry staining, and Western blot method. RESULTS: ADSCs mostly presented small sphere, fusiform and polygon shape with positive expression of CD44 and CD49d and negative expression of CD106 and vimentin. The ADSCs treated with 100 ng/mL GDF-5 presented sphere or sphere-like change and vigorous proliferation. The mRNA quantities of Col II and proteoglycan synthesized by the induced ADSCs treated with 0, 10, 100 ng/mL GDF-5 and common cultural medium increased in a dose-dependent manner at 7 days. There were significant differences among all the groups (P < 0.05), except that no significant difference was evident between the 0 ng/mL group and the 10 ng/mL group (P > 0.05). When ADSCs were treated with 100 ng/mL GDF-5 for 14 days, the Col II and the mRNA and protein quantities of proteoglycan reached the peak, and the results of alcian blue, toluidine blue and Col II immunohistochemistry stainin! g were positive. CONCLUSION: ADSCs treated with certain concen! tration of GDF-5 have higher expression of Col II and proteoglycan and possess partial biological function of chondrocyte. PMID: 19431992 [PubMed - indexed for MEDLINE] | | |
| [Experimental study of the effects of fluid dynamics on the construction of large-scale tissue engineered bone]
April 2, 2010 at 6:04 AM
|
| | [Experimental study of the effects of fluid dynamics on the construction of large-scale tissue engineered bone] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Apr;23(4):478-82 Authors: Li D, Dai K, Tang T, Lu J OBJECTIVE: To investigate the effects of flow shear stress and mass transport on the construction of large-scale tissue engineered bone using a perfusion bioreactor. METHODS: Bone marrow (20 mL) was harvested from the iliac crest of the healthy volunteer, and then hBMSCs were isolated, cultured and identified. The hBMSCs at passage 3 were seeded on the critical-size beta-TCP scaffold and cultured in a perfusion bioreactor for 28 days. Different flow shear stress (1 x, 2 x and 3 x) and different mass transport (3, 6 and 9 mL/min) were exerted on the cells seeded on the scaffold by changing the viscosity of media or perfusion flow rate. The cell proliferation and ALP activity of cells seeded on the scaffold were detected, and histology observation and morphology measurement of cell/scaffold complex were conducted. RESULTS: When the perfusion flow rabe was 3 mL/min, the cell viability of 2 x group was higher than that of other groups (P < 0.05). When the flow shea! r stress was 3 x, no significant differences were found among 3, 6 and 9 mL/min in cell viability (P > 0.05). When the perfusion flow rate was 3 mL/min, the activity of ALP of 2 x and 3 x groups was higher than that of 1 x group (P < 0.05). When the flow shear stress was 3 x, the activity of ALP of 6 mL/min group was the highest (P < 0.05). After 28 days of perfusion culture, the ECM of all the groups distributed throughout the scaffold, and the formation and mineralization of ECM was improved with the increase of flow shear stress when the perfusion flow rate was 3 mL/min. However, the increase of perfusion flow rate decreased the mineralization of ECM when the flow shear stress was 3 x. CONCLUSION: As two important fluid dynamics parameters affecting the construction of large-scale tissue engineered bone, the flow shear stress and the mass transport should be measured during the process of constructing large-scale tissue engineered bone so as to maximize their ro! les. PMID: 19431991 [PubMed - indexed for MEDLINE] | | | | 
| This email was sent to agupta1213+termsc@gmail.com. Account Login
Don't want to receive this feed any longer? Unsubscribe here
This email was carefully delivered by Feed My Inbox. 230 Franklin Road Suite 814 Franklin, TN 37064 | |
No comments:
Post a Comment