| Please add updates@feedmyinbox.com to your address book to make sure you receive these messages in the future. | |
| AID-induced T-lymphoma or B-leukemia/lymphoma in a mouse BMT model.
April 2, 2010 at 6:58 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] | | |
| Photomodulatable fluorescent proteins for imaging cell dynamics and cell fate.
April 2, 2010 at 6:55 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] | | |
| Disparate Companions: Tissue Engineering Meets Cancer Research.
April 2, 2010 at 6:55 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 6:55 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 6:55 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 6:55 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 6:55 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] | | |
| In vivo monitoring of function of autologous engineered pulmonary valve.
April 2, 2010 at 6:55 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] | | |
| [Long-term observation of prefabricated urethra with buccal mucosa in expanded capsule]
April 2, 2010 at 6:55 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 6:55 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] | | |
| [Preparation and physicochemical property of carboxymethyl-chitosan/hyaluronic acid poly(vinyl alcohol) blend membrane]
April 2, 2010 at 6:55 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-tyrosine. 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 subconju! nctival 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 6:55 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 6:55 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 6:55 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] | | |
| [Advances of nucleus pulposus cells for treating intervertebral disc degeneration]
April 2, 2010 at 6:55 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 6:55 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 6:55 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] | | |
| [Cytocompatibility study of Arg-Gly-Asp-recombinant spider silk protein/poly vinyl alcohol scaffold]
April 2, 2010 at 6:55 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 6:55 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 6:55 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] | | | | 
| This email was sent to regenmd@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