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| Neurite Outgrowth at the Biomimetic Interface.
May 5, 2010 at 7:51 AM
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| | Neurite Outgrowth at the Biomimetic Interface. Ann Biomed Eng. 2010 May 4; Authors: Kofron CM, Liu YT, López-Fagundo CY, Mitchel JA, Hoffman-Kim D Understanding the cues that guide axons and how we can optimize these cues to achieve directed neuronal growth is imperative for neural tissue engineering. Cells in the local environment influence neurons with a rich combination of cues. This study deconstructs the complex mixture of guidance cues by working at the biomimetic interface-isolating the topographical information presented by cells and determining its capacity to guide neurons. We generated replica materials presenting topographies of oriented astrocytes (ACs), endothelial cells (ECs), and Schwann cells (SCs) as well as computer-aided design materials inspired by the contours of these cells (bioinspired-CAD). These materials presented distinct topographies and anisotropies and in all cases were sufficient to guide neurons. Dorsal root ganglia (DRG) cells and neurites demonstrated the most directed response on bioinspired-CAD materials which presented anisotropic features with 90 degrees edges. DRG alig! nment was strongest on SC bioinspired-CAD materials followed by AC bioinspired-CAD materials, with more uniform orientation to EC bioinspired-CAD materials. Alignment on replicas was strongest on SC replica materials followed by AC and EC replicas. These results suggest that the topographies of anisotropic tissue structures are sufficient for neuronal guidance. This work is discussed in the context of feature dimensions, morphology, and guidepost hypotheses. PMID: 20440561 [PubMed - as supplied by publisher] | | |
| Calcium Hydroxide Promotes Cementogenesis and Induces Cementoblastic Differentiation of Mesenchymal Periodontal Ligament Cells in a CEMP1- and ERK-Dependent Manner.
May 5, 2010 at 7:51 AM
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| | Calcium Hydroxide Promotes Cementogenesis and Induces Cementoblastic Differentiation of Mesenchymal Periodontal Ligament Cells in a CEMP1- and ERK-Dependent Manner. Calcif Tissue Int. 2010 May 4; Authors: Paula-Silva FW, Ghosh A, Arzate H, Kapila S, da Silva LA, Kapila YL Periodontal tissue engineering is a complex process requiring the regeneration of bone, cementum, and periodontal ligament (PDL). Since cementum regeneration is poorly understood, we used a dog model of dental pulpal necrosis and in vitro cellular wounding and mineralization assays to determine the mechanism of action of calcium hydroxide, Ca(OH)(2), in cementogenesis. Laser capture microdissection (LCM) followed by qRT-PCR were used to assay responses of periapical tissues to Ca(OH)(2) treatment. Additionally, viability, proliferation, migration, and mineralization responses of human mesenchymal PDL cells to Ca(OH)(2) were assayed. Finally, biochemical inhibitors and siRNA were used to investigate Ca(OH)(2)-mediated signaling in PDL cell differentiation. In vivo, Ca(OH)(2)-treated teeth formed a neocementum in a STRO-1- and cementum protein-1 (CEMP1)-positive cellular environment. LCM-harvested tissues adjacent to the neocementum exhibited higher mRNA levels for ! CEMP1, integrin-binding sialoprotein, and Runx2 than central PDL cells. In vitro, Ca(OH)(2) and CEMP1 promoted STRO-1-positive cell proliferation, migration, and wound closure. Ca(OH)(2) stimulated expression of the cementum-specific proteins CEMP1 and PTPLA/CAP in an ERK-dependent manner. Lastly, Ca(OH)(2) stimulated mineralization by CEMP1-positive cells. Blocking CEMP1 and ERK function abolished Ca(OH)(2)-induced mineralization, confirming a role for CEMP1 and ERK in the process. Ca(OH)(2) promotes cementogenesis and recruits STRO-1-positive mesenchymal PDL cells to undergo cementoblastic differentiation and mineralization via a CEMP1- and ERK-dependent pathway. PMID: 20440482 [PubMed - as supplied by publisher] | | |
| Hepatic stellate cells' involvement in progenitor-mediated liver regeneration.
May 5, 2010 at 7:51 AM
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| | Hepatic stellate cells' involvement in progenitor-mediated liver regeneration. Lab Invest. 2010 May 3; Authors: Pintilie DG, Shupe TD, Oh SH, Salganik SV, Darwiche H, Petersen BE Earlier studies conducted by our laboratory have shown that suppression of transforming growth factor-beta (TGFbeta)-mediated upregulation of connective tissue growth factor (CTGF) by iloprost resulted in a greatly diminished oval cell response to 2-acetylaminofluorene/partial hepatectomy (2AAF/PH) in rats. We hypothesized that this effect is due to decreased activation of hepatic stellate cells. To test this hypothesis, we maintained rats on a diet supplemented with 2% L-cysteine as a means of inhibiting stellate cell activation during the oval cell response to 2AAF/PH. In vitro experiments show that L-cysteine did, indeed, prevent the activation of stellate cells while exerting no direct effect on oval cells. Desmin immunostaining of liver sections from 2AAF/PH animals indicated that maintenance on the L-cysteine diet resulted in an 11.1-fold decrease in the number of activated stellate cells within the periportal zones. The total number of cells proliferating i! n the periportal zones of livers from animals treated with L-cysteine was drastically reduced. Further analyses showed a greater than fourfold decrease in the magnitude of the oval cell response in animals maintained on the L-cysteine diet as determined by immunostaining for both OV6 and alpha-fetoprotein (AFP). Global liver expression of AFP as measured by real-time PCR was shown to be decreased 4.7-fold in the L-cysteine-treated animals. These data indicate that the activation of hepatic stellate cells is required for an appropriate oval cell response to 2AAF/PH.Laboratory Investigation advance online publication, 3 May 2010; doi:10.1038/labinvest.2010.88. PMID: 20440274 [PubMed - as supplied by publisher] | | |
| Fabrication of vascularized bone grafts of predetermined shape with hydroxyapatite-collagen gel beads and autogenous mesenchymal stem cell composites.
May 5, 2010 at 7:51 AM
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| | Fabrication of vascularized bone grafts of predetermined shape with hydroxyapatite-collagen gel beads and autogenous mesenchymal stem cell composites. Plast Reconstr Surg. 2010 May;125(5):1393-402 Authors: Chang SH, Tung KY, Wang YJ, Tsao YP, Ni TS, Liu HK BACKGROUND: Advances in tissue-engineering techniques have enabled new procedures to be developed for bone regeneration. In this study, for engineering of structural tissues with supporting vascular networks, the authors attempted to produce vascularized tissue-engineered bone grafts using cultured mesenchymal stem cells/hydroxyapatite/collagen gel bead composites and vascular bundle implantation. METHODS: Twenty-four New Zealand White rabbits underwent implantation of ringed polytetrafluoroethylene vascular grafts (1 x 3 cm) in the medial thigh with the femoral vascular bundle passing through. The polytetrafluoroethylene grafts were left unfilled (group A), filled with hydroxyapatite/collagen gel beads (group B), or filled with mesenchymal stem cells/hydroxyapatite/collagen gel bead composites (group C). At 4, 8, 12, and 16 weeks, the implants were removed and radiographic and histologic examinations were conducted. RESULTS: Radiographic analysis revealed that th! e area of radiopacity within the chamber was highest in group C. The average calcified densities of groups B and C were between 0.99 +/- 0.11 and 1.29 +/- 0.14. Histologically, there was fibroadipose tissue within the chamber in group A. New tissue had grown into the matrix of the chambers of groups B and C, and substitution of the biomaterials was seen. Newly formed fibrovascular networks and osteoids were simultaneously seen. Bone marrow was observed in the vascular graft of group C 6 months after implantation. CONCLUSIONS: Tissue-engineered vascularized bone grafts of predetermined shape were created with mesenchymal stem cell/hydroxyapatite/collagen gel bead composites. The results of this study showed that successful in vivo engineering of vascularized tissue-engineered bone grafts is possible. PMID: 20440159 [PubMed - in process] | | |
| Porcine allograft mandible revitalization using autologous adipose-derived stem cells, bone morphogenetic protein-2, and periosteum.
May 5, 2010 at 7:51 AM
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| | Porcine allograft mandible revitalization using autologous adipose-derived stem cells, bone morphogenetic protein-2, and periosteum. Plast Reconstr Surg. 2010 May;125(5):1372-82 Authors: Runyan CM, Jones DC, Bove KE, Maercks RA, Simpson DS, Taylor JA BACKGROUND: Critical defects of the craniomaxillofacial region are often treated with vascularized osteocutaneous free flaps. These lengthy operations may be associated with considerable donor-site morbidity and suboptimal functional and aesthetic results. To overcome these issues, this study investigates an engineered vascularized bone flap using allograft bone, adipose-derived stem cells, and recombinant human bone morphogenic protein (rhBMP)-2 and compares two alternative blood supplies. METHODS: Edentulous porcine hemimandibles were commercially sterilized, packed with rhBMP-2-soaked absorbable collagen sponge and autologous, culture-expanded adipose-derived stem cells, and implanted into two locations within 10 pigs: (1) an intercostal-based periosteal envelope (thoracic) and (2) within the rectus abdominis muscle with insertion of the superficial inferior epigastric vascular pedicle into the medullary cavity (abdominal). The constructs were incubated in vivo! for 7 to 8 weeks and harvested to assess de novo bone formation. RESULTS: Radiographic, micro-computed tomographic, and histologic assessments of harvested constructs were performed. Abdominal constructs had a thin rim of new, cancellous bone surrounding a fibrotic core with little allograft remaining. Thoracic allografts were absorbed completely and replaced with new, full-thickness, cancellous bone. Calcitic tissue content was significantly higher in thoracic (474.16 +/- 75.93 ml) compared with abdominal (143.20 +/- 46.39 ml) constructs (p < 0.006). New bone in both groups contained Haversian systems, but only thoracic constructs contained marrow elements and blood vessels resembling normal bone. CONCLUSIONS: These data demonstrate revitalization of large-volume allograft bone, and have positive implications for bone tissue engineering. Allograft revitalization in thoracic but not abdominal constructs reinforces the critical role of the periosteum in the process. PMID: 20440157 [PubMed - in process] | | |
| Identification of select glucocorticoids as Smoothened agonists: Potential utility for regenerative medicine.
May 5, 2010 at 7:51 AM
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| | Identification of select glucocorticoids as Smoothened agonists: Potential utility for regenerative medicine. Proc Natl Acad Sci U S A. 2010 May 3; Authors: Wang J, Lu J, Bond MC, Chen M, Ren XR, Lyerly HK, Barak LS, Chen W Regenerative medicine holds the promise of replacing damaged tissues largely by stem cell activation. Hedgehog signaling through the plasma membrane receptor Smoothened (Smo) is an important process for regulating stem cell proliferation. The development of Hedgehog-related therapies has been impeded by a lack of US Food and Drug Administration (FDA)-approved Smo agonists. Using a high-content screen with cells expressing Smo receptors and a beta-arrestin2-GFP reporter, we identified four FDA-approved drugs, halcinonide, fluticasone, clobetasol, and fluocinonide, as Smo agonists that activate Hedgehog signaling. These drugs demonstrated an ability to bind Smo, promote Smo internalization, activate Gli, and stimulate the proliferation of primary neuronal precursor cells alone and synergistically in the presence of Sonic Hedgehog protein. Halcinonide, fluticasone, clobetasol, and fluocinonide provide an unprecedented opportunity to develop unique clinical strategies! to treat Hedgehog-dependent illnesses. PMID: 20439738 [PubMed - as supplied by publisher] | | |
| Induction of pluripotent stem cells from adult somatic cells by protein-based reprogramming without genetic manipulation.
May 5, 2010 at 7:51 AM
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| | Induction of pluripotent stem cells from adult somatic cells by protein-based reprogramming without genetic manipulation. Blood. 2010 May 3; Authors: Cho HJ, Lee CS, Kwon YW, Paek JS, Lee SH, Hur J, Lee EJ, Roh TY, Chu IS, Leem SH, Kim Y, Kang HJ, Park YB, Kim HS The concept of reprogramming of somatic cells has opened a new era in regenerative medicine. Transduction of defined factors has successfully achieved pluripotency. However, during the generation process of induced pluripotent stem (iPS) cells, genetic manipulation of certain factors may cause tumorigenicity, which limits further application. We report that that a single transfer of ESC (embryonic stem cell)-derived proteins into primarily cultured adult mouse fibroblasts, rather than repeated transfer or prolonged exposure to materials, can achieve full reprogramming up to the pluripotent state without the forced expression of ectopic transgenes. During the process, gene expression and epigenetic status were converted from somatic to ES-equivalent status. We verified that protein-based reprogramming was neither by the contamination of protein donor ESC nor by DNAs/RNAs from donor ESC. Protein-iPS cells were biologically and functionally very similar to ES cells a! nd differentiated into 3-germ layers in vitro. Furthermore, Protein-iPS cells possessed in vivo differentiation (well-differentiated teratoma formation) and development (chimeric mice generation and a tetraploid blastocyst complementation) potentials. Our results provide an alternative and safe strategy for the reprogramming of somatic cells that can be used to facilitate pluripotent stem cell-based cell therapy. PMID: 20439621 [PubMed - as supplied by publisher] | | |
| Esophagus tissue engineering: in situ generation of rudimentary tubular vascularized esophageal conduit using the ovine model.
May 5, 2010 at 7:51 AM
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| | Esophagus tissue engineering: in situ generation of rudimentary tubular vascularized esophageal conduit using the ovine model. J Pediatr Surg. 2010 May;45(5):859-64 Authors: Saxena AK, Baumgart H, Komann C, Ainoedhofer H, Soltysiak P, Kofler K, Höllwarth ME PURPOSE: Esophagus replacement using the present surgical techniques is associated with significant morbidity. Tissue engineering of the esophagus may provide the solution for esophageal loss. In our attempts to engineer the esophagus, this study aimed to investigate the feasibility of generating vascularized in situ esophageal conduits using the ovine model. METHODS: Esophageal biopsies were obtained from lambs, and ovine esophageal epithelial cells (OEEC) were proliferated. The OEEC were seeded on to bovine collagen sheets preseeded with fibroblasts. After 2 weeks of maintaining the constructs in vitro, the constructs were tubularized on stents to create a tube resembling the esophagus and implanted into the omentum for in situ tissue engineering. The edges of the omentum were sutured using nonabsorbable suture material. The implanted constructs were retrieved after 8 and 12 weeks. RESULTS: The omental wrap provided vascular growth within and around the construc! ts as they were integrated along the outer surface area of the scaffold. After removal of the stents, the engineered conduit revealed a structure similar to the esophagus. Histologic investigations demonstrated esophageal epithelium organization into patches on the luminal side and vascular ingrowths on the conduit's outer perimeter. CONCLUSION: Our study demonstrated the seeding of OEEC on collagen scaffolds and formation of a rudimentary conduit resembling esophageal morphology after in situ omental implantation. Vascular coverage and ingrowth in the periphery of the construct could also be demonstrated. These findings hold future promise for the engineering of the esophagus with improved microarchitecture. PMID: 20438914 [PubMed - in process] | | |
| Cytocompatible Crosslinking of Electrospun Zein Fibers for the Development of Water Stable Tissue Engineering Scaffolds.
May 5, 2010 at 7:51 AM
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| | Cytocompatible Crosslinking of Electrospun Zein Fibers for the Development of Water Stable Tissue Engineering Scaffolds. Acta Biomater. 2010 Apr 30; Authors: Jiang Q, Reddy N, Yang Y This paper reports a new method of crosslinking electrospun zein fibers using citric acid (CA) as a non-toxic crosslinker to enhance the water stability and cytocompatibility of zein fibers for tissue engineering and other medical applications. Electrospun structure has many advantages over other types of structures and protein-based biomaterials possess unique properties preferred for tissue engineering and other medical applications. However, ultrafine fiber matrices developed from proteins have low the mechanical properties and morphological stability in aqueous environments required for medical applications. Efforts have been made to improve water stability of electrospun protein scaffolds using crosslinking and other approaches, but the current methods have major limitations such as low efficiency and cytotoxicity. In this research, electrospun zein fibers were crosslinked with citric acid without using any toxic catalysts. The stability of the crosslinked fi! bers in PBS solutions and their ability to support the attachment, spreading and proliferation of mouse fibroblast cells were studied. The crosslinked electrospun fibers retained their ultra-fine fibrous structure even after being treated in PBS at 37 degrees C for up to 15 days. Citric acid crosslinked electrospun zein scaffolds showed better attachment, spreading and proliferation of fibroblast cells than uncrosslinked electrospun zein fibers, crosslinked zein films, and electrospun polylactide fibers. PMID: 20438870 [PubMed - as supplied by publisher] | | |
| Does cell therapy and tissue engineering represent a promising treatment of diabetic foot ulcers?
May 5, 2010 at 7:51 AM
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| | Does cell therapy and tissue engineering represent a promising treatment of diabetic foot ulcers? Bratisl Lek Listy. 2010;111(3):138-43 Authors: Ulicna M, Danisovic L, Vojtassak J Diabetes mellitus is one of the most severe and costly chronic disease of our time. Approximately 2-3% of diabetics have an active foot ulcer, and 15% of all patients with diabetes will develop an ulcer during their lifetime. Treatment of foot complications is one of the main items in the absorption of enormous economic and health resources addressed to the diabetic patients. Advances in basic science, tissue culture techniques and cell therapy promise to improve the treatment of diabetes as well as its complications, i.e. also the ischemic ulcers of the foot. At present, the isolation of any specific type of cells, their in vitro expansion and biological characterization of acquired cell population are possible. For the healing process in ischemic diabetic ulcers, stem cells, endothelial progenitor cells and fibroblasts, both in suspension or placed on an extracellular scaffold are used. This process is focused on stimulating the new blood vessels formation. This! is stimulated by the paracrine secretion of multiple growth factors and their receptors. Verified are the vascular endothelial growth factor and its receptor, fibroblast growth factor, interleukin-8 and proangiogenic cytokines (Ref. 62). PMID: 20437823 [PubMed - in process] | | |
| Isolation and characterization of multipotent progenitor cells from the human fetal aorta wall.
May 5, 2010 at 7:51 AM
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| | Isolation and characterization of multipotent progenitor cells from the human fetal aorta wall. Exp Biol Med (Maywood). 2010 Jan;235(1):130-8 Authors: Fang B, Li Y, Song Y, Li N Recent evidence indicates that vascular progenitor cells may be the source of smooth muscle cells (SMCs) and endothelial cells (ECs). In the present study we isolated CD105(+), CD34(-) and fetal liver kinase(+) (Flk1(+)) cells from the human fetal arterial wall and demonstrated that they were vascular progenitors for both ECs and SMCs. In vitro, these cells cultured with vascular endothelial growth factor could differentiate into cells that expressed endothelial markers. Meanwhile, cells cultured with platelet-derived growth factor-BB could differentiate into cells that expressed smooth muscle markers. When transplanted into NOD/SCID mice, they contributed to neoangiogenesis in vivo during wound healing. These cells could also differentiate into osteogenic and adipogenic lineages in vitro. Hence multipotent vascular progenitor cells do exist in the arterial wall and they may have implications in the physical and pathological conditions of the vessel. Because these! cells can be expanded in culture without obvious senescence for more than 30 population doublings, they may be an important source of ECs for cellular pro- or anti-angiogenic therapies. PMID: 20404027 [PubMed - indexed for MEDLINE] | | |
| [Toxicity and side effects of artemisiae annuae CQ-189]
May 5, 2010 at 7:51 AM
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| | [Toxicity and side effects of artemisiae annuae CQ-189] Zhongguo Zhong Yao Za Zhi. 2010 Jan;35(2):204-7 Authors: Yang B, Zhou S, Li C, Wang Y OBJECTIVE: To observe the effects of artemisiae annuae CQ-189 (AACQ-189) on proliferation of hNSC and HELF in vitro, and the main organ toxicity and the median lethal dose (LD50) of kunming mouse in vivo. The purpose is to approach that the toxicity and side effects of AACQ-189. METHOD: Using techniques of the colorimetric 5-diphenyl tetrazolium bromide (MTT) to detect the effects of AACQ-189 on proliferation of hNSC, and to detect the number of HELF survival by using techniques of trypan blue exclusion. To detect LD50 by tail vein injection in kunming mouse and using histomorphology method to observe the mouse main organ damage by AACQ-189. RESULT: AACQ-189 has low poisonous function on hNSC and HELF that our experimental concentration (3.125-12.5 mg x L(-1)) has already achieve an effective dose to inhibit the proliferation of Leukemia cells obviously. LD50 concentration of kunming mouse is 550 mg x kg(-1). Moreover, AACQ-189 has little effect to main organs at ! higher concentration. CONCLUSION: AACQ-189 has low poisonous function, which is a natural anti-tumor drug and has a promising prospect for potential application. However we should do more research on its mechanism. PMID: 20394295 [PubMed - indexed for MEDLINE] | | |
| Heterotopic ossification in wartime wounds.
May 5, 2010 at 7:51 AM
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| | Heterotopic ossification in wartime wounds. J Surg Orthop Adv. 2010;19(1):54-61 Authors: Forsberg JA, Potter BK Heterotopic ossification (HO) refers to the formation of mature lamellar bone in nonosseous tissue. In the setting of high-energy wartime extremity wounds, HO is expected to complicate up to 64% of patients, has a predilection for the residual limbs of amputees, and remains a significant source of disability. Although the inciting events and the definitive cell(s) of origin continue to remain elusive, animal models and human histology samples suggest that HO formation follows a predictable sequence of events culminating in endochondral ossification. Primary prophylaxis is not medically or logistically practical in most cases because patients have generally sustained massive wounds and are undergoing serial debridements during an intercontinental aeromedical evacuation. Surgical excision of symptomatic lesions is warranted only after an appropriate trial of conservative measures and is associated with low recurrence rates in appropriately selected patients. Future ! research regarding prognostication and defining the early molecular biology of ectopic bone may permit individualized prophylaxis and development of novel targeted therapies. PMID: 20371008 [PubMed - indexed for MEDLINE] | | |
| Outcomes of internal fixation in a combat environment.
May 5, 2010 at 7:51 AM
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| | Outcomes of internal fixation in a combat environment. J Surg Orthop Adv. 2010;19(1):49-53 Authors: Stinner DJ, Keeney JA, Hsu JR, Rush JK, Cho MS, Wenke JC, Ficke JR Due to the nature of the wounds and environment, internal fixation in battlefield treatment facilities is discouraged despite the lack of data. The purpose of this review is to describe the outcomes of fractures that were internally fixed in the combat environment. The records of patients who had internal fixation performed in the theater of combat operations were reviewed. Demographics, injury characteristics, procedure history, and outcomes were recorded and analyzed. Forty-seven patients had internal fixation performed on 50 fractures in a combat theater hospital. Hip, forearm, and ankle fractures made up the majority of cases with 14 (28%), 14 (28%), and 10 (20%), respectively. Sixteen (32%) fractures were open. The average Injury Severity Score was 11.4 +/- 1.1 (range, 4-34). Thirty-nine fractures (78%) healed without incidence. There was one (2%) infection and one (2%) acute surgical complication. Ten (20%) fractures, including the one infection, required ad! ditional procedures. Because internal fixation in the combat environment was used judiciously, complications were not higher than previously reported. PMID: 20371007 [PubMed - indexed for MEDLINE] | | |
| Expression and role of phosphodiesterase 5 in human malignant melanoma cell line.
May 5, 2010 at 7:51 AM
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| | Expression and role of phosphodiesterase 5 in human malignant melanoma cell line. Anticancer Res. 2010 Feb;30(2):355-8 Authors: Murata T, Shimizu K, Watanabe Y, Morita H, Sekida M, Tagawa T BACKGROUND: Eleven phosphodiesterase (PDE) gene families (PDE1-11) have been identified, and some PDE isoforms are selectively expressed in various cell types. Previously, we reported PDE1, PDE3 and PDE4 expressions in human malignant melanoma cells. However, the expression and role of PDE5 in malignant melanoma cells is not clear. Therefore, we characterized PDE5 in human malignant melanoma MAA cells. MATERIALS AND METHODS: PDE5 activity and PDE5A mRNA expression were investigated in MAA cells. The full open reading frames for human PDE5A1 were sequenced. Effects of PDE5 inhibitors on cell growth were determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assays. RESULTS: PDE5 activity and PDE5A1 mRNA expression were detected in MAA cells. The nucleotide sequence of PDE5A1 was identical to that of human PDE5A1, previously published. Two PDE5 inhibitors inhibited the growth of cells. CONCLUSION: PDE! 5A1 mRNA is expressed and may play an important role in the growth of human malignant melanoma MAA cells. PMID: 20332439 [PubMed - indexed for MEDLINE] | | |
| [An experimental study on repairing full-thickness skin wound by human acellular amniotic membrane loaded with adipose-derived stem cells in rats]
May 5, 2010 at 7:51 AM
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| | [An experimental study on repairing full-thickness skin wound by human acellular amniotic membrane loaded with adipose-derived stem cells in rats] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2010 Feb;24(2):143-9 Authors: Ju X, Pan F, Bai S, Tian X, Tong H, Wang J OBJECTIVE: Human acellular amniotic membrane (HAAM) contains collagens, glycoproteins, protein-polysaccharide, integrin, and lamellar, which can supply rich nutrition to cell proliferation and differentiation. To explore the possibility of HAAM with adipose-derived stem cells (ADSCs) as a good engineered skin substitute for repairing skin defect. METHODS: Primary ADSCs were obtained from inguinal fat of 30 healthy 4-month-old SD rats, male or female, weighing 250-300 g, and cultured in vitro and purified. The 3rd passage ADSCs were used to detect CD44, CD49d and CD34 by immunocytochemistry staining. After physical and trypsin preparation, the HAAM was observed by HE staining and scanning electron microscope(SEM) respectively. ADSCs were seeded on epithelial side of HAAM at the density of 2 x 10(5)/cm2, cocultured, and observed by SEM at different time. MTT test was used to detect viability of cells that seeded on HAAM, the group without HAAM was used as control. T! hirty SD rats were made models of full-thickness skin wound and randomly divided into three groups (A, B, and C). Wound was repaired with HAAM/ADSCs composites in group A, with HAAM in group B, and with gauze as control in group C. The rats underwent postoperative assessment of wound healing rate and histological observation at the 1st, 2nd, and 4th weeks. RESULTS: HE staining showed that the 3rd passage ADSCs was spindle-shaped with an ovoid nucleus which located in the middle of cell; the immunocytochemistry staining showed positive result for CD44 and CD49d and negative result for CD34. There were no residues of cells in the HAAM by HE staining. SEM showed that there were different structures at the two sides of HAAM: one side had compact reticular structure and the other side had fibrous structure. After 3 days of co-culture, ADSCs showed good growth on HAAM; the cells were closely packed onto the HAAM, attached firmly and proliferated to confluence on the stromal surfa! ce of HAAM. MTT test showed that the cells on the HAAM grew we! ll and h ad strong proliferation vitality. There was no significant difference between ADSCs cultured in the HAAM and control group (P > 0.05). One, 2, 4 weeks after graft, there were significant differences in wound healing rate between group A and groups B, C (P < 0.05), between group B and group C (P < 0.05). HE staining showed that wound healed faster in group A than in groups B, C. Cytokeratin 19 (CK19) immunohistochemical staining showed that there were more CK19 positive cells in group A than in groups B, C. CONCLUSION: The graft of HAAM with ADSCs plays an effective role in promoting the repair of full-thickness skin wound. PMID: 20187443 [PubMed - indexed for MEDLINE] | | |
| [Experimental study on culturing dermal papillae cells with keratinocyte medium]
May 5, 2010 at 7:51 AM
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| | [Experimental study on culturing dermal papillae cells with keratinocyte medium] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2010 Feb;24(2):138-42 Authors: Jiao H, Fan J, Liu L, Kang N, Tian J, Gan C, Feng S, Yan L, Gu C OBJECTIVE: Dermal papillae cells are widely applied to reconstruction of tissue engineered hair follicle and skin. To investigate the difference of the biological characteristics of dermal papillae cells cultured with keratinocyte medium (KM) and normal medium (NM), and to determine whether it is feasible for the reconstruction of tissue engineered hair follicle using dermal papillae cells cultured in KM. METHODS: Scalp samples were obtained in rhytidectomy procedure. Dermal papillae were isolated by two steps digestive treatment, then cultured with KM and NM in two groups. The time of dermal papillae adherence and cell outgrowth was recorded and the rate of dermal papillae adherence was determined after 5 days. As well as, the difference of cell morphology was observed through inverted phase contrast microscope. The maximum generations were determined in two groups and the cell sheets were observed by HE staining. In third-generation cells, the number of aggregat! es in every dish and the proliferation by MTT were compared between two groups. Meanwhile, the expression of a-smooth muscle actin (alpha-SMA) and ALP were detected by immunofluorescence and specific staining in two groups. RESULTS: Dermal papillae of KM group had a higher rate of adherence and fast outgrowth. The rates of adherence were 54.17% and 36.78% in KM group and in NM group, respectively. In KM group, cells adhered after 24 hours and outgrew after 64 hours. While, cells adhered after 48 hours and outgrew after 80 hours in NM group. The cells were bigger in NM group than in KM group. In third-generation cells, 3.06 +/- 1.12 and 9.25 +/- 1.73 aggregates formed in NM group and KM group, respectively, the difference was significant (P < 0.05). In addition, cells could form cell sheets which were muti-layers in KM group. Mostly 7 and 15 generations could been subcultured in NM group and KM group, respectively. The result of MTT indicated that cells proliferated more ! actively in KM group; absorbance value of KM group was signifi! cantly h igher than that of NM group after 7 days (P < 0.05). The positive of alpha-SMA were detected in the third-generation cells of both groups. Occasionally a little few cells expressed ALP with (987 +/- 146) microm2 positive area in the sixth-generation cells of NM group. However, the cells still expressed ALP with (8 757 +/- 558) microm2 positive area in the fourteenth-generation cells of KM group and the difference was significant (P < 0.05). CONCLUSION: Cells proliferate actively and aggregate obviously and could been subcultured more generations in KM. Therefore, culturing dermal papillae cells with KM is feasible for the reconstruction of tissue engineered hair follicle. PMID: 20187442 [PubMed - indexed for MEDLINE] | | |
| Fabrication and evaluation of reconstructed cardiac tissue and its application to bio-actuated microdevices.
May 5, 2010 at 7:51 AM
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| | Fabrication and evaluation of reconstructed cardiac tissue and its application to bio-actuated microdevices. IEEE Trans Nanobioscience. 2009 Dec;8(4):349-55 Authors: Horiguchi H, Imagawa K, Hoshino T, Akiyama Y, Morishima K In this paper, we proposed to utilize a reconstructed cardiac tissue as microactuator with easy assembly. In a glucose solution, cardiomyocytes can contract autonomously using only chemical energy. However, a single cardiomyocyte is not enough to actuate a microrobot or a mechanical system. Though the output power will increase by using multiple cardiomyocyte, it is difficult to assemble those cardiomyocyte to predefined positions one-by-one using a micromanipulator. Reconstructed cardiac tissue not only will enable researchers to assemble the cells easily and but also has a potential to improve the contractile ability. To realize a bio-actuator in this paper, we reconstructed a microcardiac tissue using an extracellular matrix, and their displacements, displacement frequency, contractile force, and lifetime of the reconstructed cardiac tissue were evaluated. Electrical and pharmacological responses of the reconstructed cardiac tissue were also evaluated. Finally,! a bioactuator, a primitive micropillar actuator, was fabricated and applicability of the reconstructed cardiac tissue for bioactuators was evaluated. PMID: 20142148 [PubMed - indexed for MEDLINE] | | |
| Intracellular Na(+) and Ca(2+) modulation increases the tensile properties of developing engineered articular cartilage.
May 5, 2010 at 7:51 AM
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| | Intracellular Na(+) and Ca(2+) modulation increases the tensile properties of developing engineered articular cartilage. Arthritis Rheum. 2010 Apr;62(4):1097-107 Authors: Natoli RM, Skaalure S, Bijlani S, Chen KX, Hu J, Athanasiou KA OBJECTIVE: Significant collagen content and tensile properties are difficult to achieve in tissue-engineered articular cartilage. The aim of this study was to investigate whether treating developing tissue-engineered cartilage constructs with modulators of intracellular Na(+) or Ca(2+) could increase collagen concentration and construct tensile properties. METHODS: Inhibitors of Na(+) ion transporters and stimulators of intracellular Ca(2+) were investigated for their ability to affect articular cartilage development in a scaffoldless, 3-dimensional chondrocyte culture. Using a systematic approach, we applied ouabain (Na(+)/K(+)-ATPase inhibitor), bumetanide (Na(+)/K(+)/2Cl(-) tritransporter inhibitor), histamine (cAMP activator), and ionomycin (a Ca(2+) ionophore) to tissue-engineered constructs for 1 hour daily on days 10-14 of culture and examined the constructs at 2 weeks or 4 weeks. The gross morphology, biochemical content, and compressive and tensile mechan! ical properties of the constructs were assayed. RESULTS: The results of these experiments showed that 20 microM ouabain, 0.3 microM ionomycin, or their combination increased the tensile modulus by 40-95% compared with untreated controls and resulted in an increased amount of collagen normalized to construct wet weight. In constructs exposed to ouabain, the increased percentage of collagen per construct wet weight was secondary to decreased glycosaminoglycan production on a per-cell basis. Treatment with 20 microM ouabain also increased the ultimate tensile strength of neo-tissue by 56-86% at 4 weeks. Other construct properties, such as construct growth and type I collagen production, were affected differently by Na(+) modulation with ouabain versus Ca(2+) modulation with ionomycin. CONCLUSION: These data are the first to show that treatments known to alter intracellular ion concentrations are a viable method for increasing the mechanical properties of engineered articular c! artilage and identifying potentially important relationships t! o hydros tatic pressure mechanotransduction. Ouabain and ionomycin may be useful pharmacologic agents for increasing tensile integrity and directing construct maturation. PMID: 20131245 [PubMed - indexed for MEDLINE] | | |
| The intriguing links between prominin-1 (CD133), cholesterol-based membrane microdomains, remodeling of apical plasma membrane protrusions, extracellular membrane particles, and (neuro)epithelial cell differentiation.
May 5, 2010 at 7:51 AM
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| | The intriguing links between prominin-1 (CD133), cholesterol-based membrane microdomains, remodeling of apical plasma membrane protrusions, extracellular membrane particles, and (neuro)epithelial cell differentiation. FEBS Lett. 2010 May 3;584(9):1659-64 Authors: Corbeil D, Marzesco AM, Wilsch-Bräuninger M, Huttner WB Prominin-1 (CD133) is a cholesterol-interacting pentaspan membrane protein concentrated in plasma membrane protrusions. In epithelial cells, notably neuroepithelial stem cells, prominin-1 is found in microvilli, the primary cilium and the midbody. These three types of apical membrane protrusions are subject to remodeling during (neuro)epithelial cell differentiation. The protrusion-specific localization of prominin involves its association with a distinct cholesterol-based membrane microdomain. Moreover, the three prominin-1-containing plasma membrane protrusions are the origin of at least two major subpopulations of prominin-1-containing extracellular membrane particles. Intriguingly, the release of these particles has been implicated in (neuro)epithelial cell differentiation. PMID: 20122930 [PubMed - indexed for MEDLINE] | | |
| Platelet-rich plasma impairs osteoclast generation from human precursors of peripheral blood.
May 5, 2010 at 7:51 AM
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| | Platelet-rich plasma impairs osteoclast generation from human precursors of peripheral blood. J Orthop Res. 2010 Jun;28(6):792-7 Authors: Cenni E, Avnet S, Fotia C, Salerno M, Baldini N Platelet-rich plasma is used to accelerate bone repair for the release of osteogenic growth factors from activated platelets. To date, the effects on osteoclasts have been only scarcely investigated, even though these cells are crucial for bone remodeling. The aim of this research was the evaluation of the effects of thrombin-activated platelets (PRP) on osteoclastogenesis from human blood precursors. We evaluated both the ability to influence osteoclast differentiation induced by the receptor activator of nuclear factor-kappaB ligand (RANKL), and the ability to induce osteoclast differentiation without RANKL. In both assays, the incubation with PRP supernatant at 10% did not significantly affect the formation of tartrate-resistant acid phosphatase (TRACP)-positive multinucleated cells that were able to form the F-actin ring. However, when PRP at 25 and 50% was added to the medium without RANKL, the generation of TRACP-positive multinucleated cells was inhibited. ! PRP, even at 10%, reduced the osteoclast-mediated bone collagen degradation, suggesting inhibition of osteoclast activation. Similarly, after incubation with PRP supernatant, calcitonin receptor mRNA was lower than the untreated samples. In conclusion, PRP at 10% interfered with the complete differentiation process of human osteoclast precursors. At higher concentration it impaired osteoclast formation also at an early stage of differentiation. PMID: 20058277 [PubMed - indexed for MEDLINE] | | |
| Chondrogenic differentiation and lubricin expression of caprine infraspinatus tendon cells.
May 5, 2010 at 7:51 AM
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| | Chondrogenic differentiation and lubricin expression of caprine infraspinatus tendon cells. J Orthop Res. 2010 Jun;28(6):716-25 Authors: Funakoshi T, Spector M Reparative strategies for the treatment of injuries to tendons, including those of the rotator cuff of the shoulder, need to address the formation of the cartilage which serves as the attachment apparatus to bone and which forms at regions undergoing compressive loading. Moreover, recent work indicates that cells employed for rotator cuff repair may need to synthesize a lubricating glycoprotein, lubricin, which has recently been found to play a role in tendon tribology. The objective of the present study was to investigate the chondrogenic differentiation and lubricin expression of caprine infraspinatus tendon cells in monolayer and three-dimensional culture, and to compare the behavior with bone marrow-derived mesenchymal stem cells (MSCs). The results demonstrated that while tendon cells in various media, including chondrogenic medium, expressed lubricin, virtually none of the MSCs synthesized this important lubricating molecule. Also of interest was that the ca! rtilage formation capacity of the tendon cells grown in pellet culture in chondrogenic medium was comparable with MSCs. These data inform the use of tendon cells for rotator cuff repair, including for fibrocartilaginous zones. PMID: 20058273 [PubMed - indexed for MEDLINE] | | |
| Medaka Oct4 is expressed during early embryo development, and in primordial germ cells and adult gonads.
May 5, 2010 at 7:51 AM
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| | Medaka Oct4 is expressed during early embryo development, and in primordial germ cells and adult gonads. Dev Dyn. 2010 Feb;239(2):672-9 Authors: Sánchez-Sánchez AV, Camp E, GarcÃa-España A, Leal-Tassias A, Mullor JL Oct4 is a crucial transcription factor for controlling pluripotency in embryonic stem cells and the epiblast of mouse embryos. We have characterized the expression pattern of medaka (Oryzias latipes) Ol-Oct4 during embryonic development and in the adult gonads. Genomic analysis showed that Ol-Oct4 is the ortholog of zebrafish spg/pou2. However, their expression patterns are not the same, suggesting that Oct4 may play different roles in zebrafish and medaka. Using specific antibodies for the Ol-Oct4 protein, we showed that Ol-Oct4 is also expressed in primordial germ cells, in the spermatogonia (male germ stem cells), and during different stages of oocyte development. These results suggest that Ol-Oct4 plays a post-embryonic role in the maturing gonads and gametes. The Ol-Oct4 mRNA and protein expression patterns are similar to those of mammalian Oct4 and introduce medaka fish as a valid model for the functional and evolutionary study of pluripotency genes in vivo.! PMID: 20034054 [PubMed - indexed for MEDLINE] | | |
| Cartilage regeneration using adipose-derived stem cells and the controlled-released hybrid microspheres.
May 5, 2010 at 7:51 AM
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| | Cartilage regeneration using adipose-derived stem cells and the controlled-released hybrid microspheres. Joint Bone Spine. 2010 Jan;77(1):27-31 Authors: Han Y, Wei Y, Wang S, Song Y OBJECTIVE: This study was to evaluate the effect of hybrid microspheres (MS) composed of gelatin transforming growth factor-beta (TGF-beta1)-loaded MS and chitosan MS on the enhancement of differentiation of adipose-derived stem cells (ASCs) into chondrocytes in pellet culture in vitro and the reparative capacity of pellet from ASCs and the hybrid MS-TGF used to repair cartilage defects in vivo. METHODS: The morphology of the controlled-released MS was observed with scanning electron microscopy (SEM) and mechanical property was also tested in this study. In vitro TGF-beta1 release was evaluated by an enzyme-linked immunosorbent assay. The protein expression of Collagen II was tested by Western blot. In addition, a preliminary study on cartilage regeneration was also performed in vivo. RESULTS: When chondrogenic differentiation of ASCs in both MS was evaluated, the protein expression of Collagen II became significantly increased for the hybrid MS-TGF, as compared w! ith the gelatin MS-TGF. Mechanical result showed that the hybrid MS was superior to the gelatin MS. Observation of histology in vivo demonstrated that the pellet from ASCs and the hybrid MS-TGF promoted cartilage regeneration in the defects of articular cartilage much better than other groups. CONCLUSION: Our study demonstrated that the pellet from ASCs and the hybrid MS-TGF can provide an easy and effective way to construct the tissue engineered cartilage in vitro and in vivo. PMID: 20022784 [PubMed - indexed for MEDLINE] | | |
| [Property studies on three-dimensional porous blended silk scaffolds]
May 5, 2010 at 7:51 AM
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| | [Property studies on three-dimensional porous blended silk scaffolds] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Oct;23(10):1264-70 Authors: Rao J, Shen J, Quan D, Xu Y OBJECTIVE: To explore the differences of three-dimensional porous blended silk scaffolds with different sericin ratios in terms of molecular structure, mechanical properties, and biological characteristics. METHODS: Fibroin/sericin blended aqueous solution [concentration 8% (W/V)] with various sericin ratios 0%, 2%, 4%, 6%, 8%, 10%, 12% and NaCl as a porogen with different particle sizes (125-200, 200-300, 300-450, 450-600, 600-900, 900-1100 microm) were used to fabricate the three-dimensional porous blended silk scaffolds. Gross observation of the formation of three-dimensional porous blended silk scaffolds of different sericin ratios and pore sizes was performed. Scanning electron microscope (SEM) was used to detect the distribution and diameter of the pore sizes. Its porosity was calculated by liquids replacement method. X-ray diffractometer (XRD) and fourier transform infrared (FTIR) were used to detect its internal molecular structure. Its mechanical properti! es, enzyme degration rate in vitro and experiment on SD rats in vivo, and histology observation after coculturing homogeneous scaffold (sericin ratio 0-12%, NaCl particle size 600-900 microm) with adipose tissue-derived mesenchymal stem cells (ADSCs) were detected. RESULTS: Gross observation showed that the higher of the ratio of sericin protein, the greater of the porogen sizes scope which used to form homogeneous silk scaffolds. The result of SEM showed that the pores of the three-dimensional porous blended silk scaffolds had uniform distribution and was connected with each other. Its pore sizes was in the scope of the porogen sizes, and its porosity all above 90%. The angel corresponding to the characteristic peak of the sericin/fibroin blended scaffolds were 20.6 degrees and 24.6 degrees (XRD), and the wavelength corresponding to the characteristic peak of the sericin/fibroin blended scaffolds were 3 296, 2 933 and 1629 cm(-1) (FTIR) which was the same as the angel and ! wavelength corresponding to the characteristic peak of the nat! ural sil k. The mechanical properties of the sericin/fibroin blended scaffolds was improved with the increase of sericin ratios, and the compressional resilience reached 100% when the ratio > or = 6%. The different ratios of sericin and the different particle size of porogen had no significant effect on the enzyme degradation rate in vitro. The histological observation 14 days after ADSCs-scaffold co-culture indicated that the scaffolds had slow degradation rate, and slight inflammatory response in vivo. ADSCs were well attached to the sericin/fibroin blended scaffolds of different sericin ratios, with varied morphology, rich cytoplasm, and nuclear enrichment, the light staining ECM was observed surrounding the cells. CONCLUSION: The mechanical property of the three-dimensional porous blended silk scaffolds is improved by silk sericins with ratio > or = 6% obviously, which will lay the groudwork for further research and making of strengthen silk scaffolds. PMID: 19957853 [PubMed - indexed for MEDLINE] | | |
| [Comparison between canine decellularized venous valve stent combined with endothelial progenitor cells and native venous valve on venous valve closure mechanism in normal physiological conditions]
May 5, 2010 at 7:51 AM
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| | [Comparison between canine decellularized venous valve stent combined with endothelial progenitor cells and native venous valve on venous valve closure mechanism in normal physiological conditions] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Oct;23(10):1260-3 Authors: Wei Z, Liu C, Zhou M, Qiao W OBJECTIVE: To compare canine decellularized venous valve stent combining endothelial progenitor cells (EPC) with native venous valve in terms of venous valve closure mechanism in normal physiological conditions. METHODS: Thirty-six male hybrid dogs weighing 15-18 kg were used. The left femoral vein with valve from 12 dogs was harvested to prepare decellularized valved venous stent combined with EPC. The rest 24 dogs were randomly divided into the experimental group and the control group (n=12 per group). In the experimental group, EPC obtained from the bone marrow through in vitro amplification were cultured, the cells at passage 3 (5 x 10(6) cells/mL) were seeded on the stent, and the general and HE staining observations were performed before and after the seeding of the cells. In the experimental group, allogenic decellularized valved venous stent combined with EPC was transplanted to the left femoral vein region, while in the control group, the autogenous vein ! venous valve was implanted in situ. Color Doppler Ultrasound exam was performed 4 weeks after transplantation to compare the direction and velocity of blood flow in the distal and proximal end of the valve, and the changes of vein diameter in the valve sinus before and after the closure of venous valve when the dogs changed from supine position to reverse trendelenburg position. RESULTS: General and HE staining observations before and after cell seeding: the decellularized valved venous stent maintained its fiber and collagen structure, and the EPC were planted on the decellularized stent successfully through bioreactor. During the period from the reverse trendelenburg position to the starting point for the closure of the valve, the reverse flow of blood occurred in the experimental group with the velocity of (1.4 +/- 0.3) cm/s; while in the control group, there was no reverse flow of blood, but the peak flow rate was decreased from (21.3 +/- 2.1) cm/s to (18.2 +/- 3.3) cm/! s. In the control group, the active period of valve, the start! ing poin t for the closure of the valve, and the time between the beginning of closure and the complete closure was (918 +/- 46), (712 +/- 48), and (154 +/- 29) ms, respectively; while in the experimental group, it was (989 +/- 53), (785 +/- 43), and (223 +/- 29) ms, respectively. There was significant difference between two groups (P < 0.05). After the complete closure of valve, no reverse flow of blood occurred in two groups. The vein diameter in the valve sinus of the experimental and the control group after the valve closure was increased by 116.8% +/- 2.0% and 118.5% +/- 2.2%, respectively, when compared with the value before valve closure (P > 0.05). CONCLUSION: Canine decellularized venous valve stent combined with EPC is remarkably different from natural venous valve in terms of the valve closure mechanism in physiological condition. The former relies on the reverse flow of blood and the latter is related to the decreased velocity of blood flow and the increased pressur! e of vein in the venous sinus segment. PMID: 19957852 [PubMed - indexed for MEDLINE] | | |
| [Experimental study of repairing bone defect with tissue engineered bone seeded with autologous red bone marrow and wrapped by pedicled fascial flap]
May 5, 2010 at 7:51 AM
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| | [Experimental study of repairing bone defect with tissue engineered bone seeded with autologous red bone marrow and wrapped by pedicled fascial flap] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Oct;23(10):1254-9 Authors: Yang X, Shi W, Du Y, Meng X, Yin Y OBJECTIVE: To investigate the effect of repairing bone defect with tissue engineered bone seeded with the autologous red bone marrow (ARBM) and wrapped by the pedicled fascial flap and provide experimental foundation for clinical application. METHODS: Thirty-two New Zealand white rabbits (male and/or female) aged 4-5 months old and weighing 2.0-2.5 kg were used to make the experimental model of bilateral 2 cm defect of the long bone and the periosteum in the radius. The tissue engineered bone was prepared by seeding the ARBM obtained from the rabbits on the osteoinductive absorbing material containing BMP. The left side of the experimental model underwent the implantation of autologous tissue engineered bone serving as the control group (group A). While the right side was designed as the experimental group (group B), one 5 cm x 3 cm fascial flap pedicled on the nameless blood vessel along with its capillary network adjacent to the bone defect was prepared using mi! crosurgical technology, and the autologous tissue engineered bone wrapped by the fascial flap was used to fill the bone defect. At 4, 8, 12, and 16 weeks after operation, X-ray exam, absorbance (A) value test, gross morphology and histology observation, morphology quantitative analysis of bone in the reparative area, vascular image analysis on the boundary area were conducted. RESULTS: X-ray films, gross morphology observation, and histology observation: group B was superior to group A in terms of the growth of blood vessel into the implant, the quantity and the speed of the bone trabecula and the cartilage tissue formation, the development of mature bone structure, the remodeling of shaft structure, the reopen of marrow cavity, and the absorbance and degradation of the implant. A value: there was significant difference between two groups 8, 12, and 16 weeks after operation (P < 0.05), and there were significant differences among those three time points in groups A and B! (P < 0.05). For the ratio of neonatal trabecula area to th! e total reparative area, there were significant differences between two groups 4, 8, 12, and 16 weeks after operation (P < 0.05), and there were significant differences among those four time points in group B (P < 0.05). For the vascular regenerative area in per unit area of the junctional zone, group B was superior to group A 4, 8, 12, and 16 weeks after operation (P < 0.05). CONCLUSION: Tissue engineered bone, seeded with the ARBM and wrapped by the pedicled fascial flap, has a sound reparative effect on bone defect due to its dual role of constructing vascularization and inducing membrane guided tissue regeneration. PMID: 19957851 [PubMed - indexed for MEDLINE] | | |
| [Application of technique of labeling BMSCs with PKH26 to tissue engineered bone construction]
May 5, 2010 at 7:51 AM
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| | [Application of technique of labeling BMSCs with PKH26 to tissue engineered bone construction] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Oct;23(10):1246-9 Authors: Zhang N, Ma H, Zhang Y, Li B, Zhou M, Wang X, Zhao Y, Li B OBJECTIVE: To explore the feasibility of using PKH26 as a cell tracer to construct tissue engineered bone. METHODS: BMSCs isolated from the bone marrow of 1-week-old New Zealand white rabbit were cultured. The BMSCs at passage 3 were labeled with PKH26 and were observed under fluorescence microscope. The percentage of the labeled cells was detected by Flow cytometer. The labeled cells were induced to differentiate into osteoblasts in vitro and the morphology of the cells after induction was observed under inverted phase contrast microscope. The osteogenic induction was evaluated by ALP staining and Alizarin red staining. The cells labeled with PKH26 were seeded on the bio-derived bone to construct tissue engineered bone in vitro. Then the compound of cells and material were observed under fluorescence microscope. The compound of labeled cells and material were implanted into the rabbit thigh muscle, and the transformation of the labeled cells was observed by fluor! escence microscope 14 and 28 days later. RESULTS: Fluorescence microscope observation: the BMSCs labeled by PKH26 were spherical and presented with red and uniform-distributed fluorescence, and the contour of the cells were clearly observed when they were adherent 24 hours after culture. Flow cytometric detection revealed that the percentage of labeled cells was 97.2%. After osteogenic induction, the morphology of the cells changed from long-fusiform to polygon-shape or cube-shape, more ECM was secreted, and the ALP and the Alizarin red staining were positive. At 48 hours after culturing the PKH26 labeled BMSCs with bio-derived bone, the fluorescence microscope observation showed that there was red fluorescence on the surface and inside of the material. At 14 days after implantation, the labeled cells with red and light fluorescence were evident in the implantation area; while at 28 days, the cells with red fluorescence were still evident but less in quantity and weaker in ! fluorescence strength. CONCLUSION: PKH26 can be used as BMSCs ! label fo r the construction of tissue engineered bone in vitro and the short-term tracing in vivo. PMID: 19957849 [PubMed - indexed for MEDLINE] | | |
| [Effect of vitreous-cryopreservation on in vivo implantation of tissue engineered tendons]
May 5, 2010 at 7:51 AM
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| | [Effect of vitreous-cryopreservation on in vivo implantation of tissue engineered tendons] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Oct;23(10):1229-34 Authors: Liao M, Liu C, Zhu M, Qin T OBJECTIVE: To study the immunological rejection occurred in different period after the in vivo implantation of vitreous-cryopreservation tissue engineered tendons for the repair of tendon defect and investigate its influences on the hepatic, renal, and cardiovascular function of rats. METHODS: Tenocytes obtained from tail tendon of one-week-old SD rats were cultured in vitro. The tenocytes at passage 2-4 (5 x 10(6) cells/mL) were co-cultured with 1.5 cm bio-derived tendon material to reconstruct tissue engineered tendon. The 21% DMSO was used as cryopreservation protection solution and the Eurocollins solution served as basic solution for pre-frozen solution (4 degrees C) and eluent. The cell-scaffold composites were vitreous-cryopreserved by self-designed method. Seventy-two healthy SD rats (male and/or female) weighing 210-230 g were randomly divided into three groups: group A (n = 32), group B (n = 32), and group C (n = 8). The 0.5 cm tendon defect model was es! tablished in the middle part of Achilles tendon in groups A and B. The defect in group A and B was repaired by the transplantation of tissue engineered tendon with and without vitreous-cryopreservation, respectively. At 2, 4, 6, and 8 weeks after transplantation, the general observation and the detection of hepatic function, renal function, and cardiovascular function were conducted. At 2, 4, and 6 weeks after transplantation, serum immunology test was conducted. RESULTS: There were no tissue necrosis, hydrops, and suppurative infection in groups A and B. The adhesion was evident in groups A and B 2 weeks after transplantation, improved gradually during 4-6 weeks, and disappeared at 8 weeks. The neonatal tissue had full integration and continuity, and the bridging region of the tendon healed and was similar to the normal tendon. For serum IgG and IgM content, there was no significant difference when group A or B was compared with group C, and between group A and group B 2, ! 4, and 6 weeks after transplantation (P > 0.05). Hepatic fu! nction: aspartate aminotransferase (AST) content of group A was less than that of group C 4 weeks after transplantation (P < 0.05); AST content of group B was less than that of group C 4 and 6 weeks after transplantation (P < 0.05); but there was no significant difference when group A or B was compared with group C in terms of other indexes 8 weeks after transplantation (P > 0.05). Renal function: serum albumin and creatinine in groups A and B were decreased obviously, and significant difference was evident when compared with group C (P < 0.05). Cardiovascular function: there was no significant difference between group A and group C in terms of blood glucose, triglyceride, and cholesterol (P > 0.05); there was a significant difference between group B and group C in terms of triglyceride 8 weeks after transplantation (P < 0.05). CONCLUSION: Repairing tendon defect with the implantation of vitreous-cryopreservation tissue engineered tendons results in no obvious immu! nological rejection and exerts no obvious influences on hepatic, renal, and cardiovascular function. PMID: 19957846 [PubMed - indexed for MEDLINE] | | |
| [Preliminary study on prefabricated urethra in expander capsule]
May 5, 2010 at 7:51 AM
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| | [Preliminary study on prefabricated urethra in expander capsule] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Oct;23(10):1212-5 Authors: Li P, Li Z, Cai M, Zhan S, Shi B, Jin H, Wang S, Wang Q, Xu L OBJECTIVE: To investigate the feasibility of prefabricating urethra in the expander capsule with gelatin sponge and micro-mucosa compound transplantation. METHODS: Eight 8-week-old Guizhou miniature pigs (male and/or female) weighing 20-25 kg were used. Six expanders (15 mL) were placed subcutaneously on the dorsal thorax of each miniature pig. Autologous oral mucosa of every pig was harvested 2 weeks later to prepare micro-mucosa with a diameter less than 1 mm. Gelatin sponge 3 cm x 2 cm in size was transplanted to the expander capsule after being coated by the autologous micro-mucosa at the area expansion ratio of 4 : 1 (group A), 8 : 1 (group B), and 16 : 1 (group C), respectively (n = 2 per group). The implantation of gelatin sponge served as the blank control (group D, n = 2). Physiological saline was injected into the expander immediately after operation, and the pressure in the expander was 40 mm Hg (1 mm Hg = 0.133 kPa). The postoperative general condition! of the animals was observed. At 1, 2, and 3 weeks after operation, the animals were killed to receive general, HE staining, and immunohistochemistry staining observations. RESULTS: All animals survived till the end of the experiment. The wounds healed well. General observation: in groups A, B, and C at 1 week after operation, there was no obvious degeneration of gelatin, the mucous was survived partially, and there were significant differences among three groups in terms of mucosa healing rate (P < 0.05), groups A and B were better than group C, and group A was better than group B; at 2 weeks, the gelatin sponge was partly absorbed, most of the mucosa survived, and the mucosa healing rate of groups A and B was better than that of group C (P < 0.05); at 3 weeks, the gelatin sponge was still not absorbed completely, the wound reached epithelialization approximately, and there were no significant differences among three groups in terms of mucosa healing rate (P > 0.0! 5). No neo-mucosa was evident in group D at each time point. H! istology and immunohistochemistry staining observation: at each time point, the mucosa epithelium survival, inflammatory cell infiltration, and pan-cytokeratin were evident in groups A, B, and C; at 3 weeks after operation, the stratified squamous epithelium presented obvious polarity and the submucous neovascularization was abundant in groups A, B, and C. There was no mucosa epithelium and positive stained pan-cytokeratin in group D. For the percentage of positive pan-cytokeratin stained area, there were significant differences among groups A, B, and C 1 week after operation (P < 0.05); at 2 and 3 weeks after operation, there was significant difference between group A and group C, and between group B and group C (P < 0.05); but no significant difference was evident between group A and group B (P > 0.05). CONCLUSION: Micro-mucosa and gelatin spongy compound transplantation on the expander capsule can form mucosal lining, achieve complete epithelialization in 2 weeks, and co! ntribute to maintain the normal function of prefabricated urethra. PMID: 19957842 [PubMed - indexed for MEDLINE] | | |
| A multichamber fluidic device for 3D cultures under interstitial flow with live imaging: development, characterization, and applications.
May 5, 2010 at 7:51 AM
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| | A multichamber fluidic device for 3D cultures under interstitial flow with live imaging: development, characterization, and applications. Biotechnol Bioeng. 2010 Apr 1;105(5):982-91 Authors: Bonvin C, Overney J, Shieh AC, Dixon JB, Swartz MA Interstitial flow is an important biophysical cue that can affect capillary morphogenesis, tumor cell migration, and fibroblast remodeling of the extracellular matrix, among others. Current models that incorporate interstitial flow and that are suitable for live imaging lack the ability to perform multiple simultaneous experiments, for example, to compare effects of growth factors, extracellular matrix composition, etc. We present a nine-chamber radial flow device that allows simultaneous 3D fluidic experiments for relatively long-term culture with live imaging capabilities. Flow velocity profiles were characterized by fluorescence recovery after photobleaching (FRAP) for flow uniformity and estimating the hydraulic conductivity. We demonstrate lymphatic and blood capillary morphogenesis in fibrin gels over 10 days, comparing flow with static conditions as well as the effects of an engineered variant of VEGF that binds fibrin via Factor XIII. We also demonstrate t! he culture of contractile fibroblasts and co-cultures with tumor cells for modeling the tumor microenvironment. Therefore, this device is useful for studies of capillary morphogenesis, cell migration, contractile cells like fibroblasts, and multicellular cultures, all under interstitial flow. PMID: 19953672 [PubMed - indexed for MEDLINE] | | |
| Fusion of uniluminal vascular spheroids: a model for assembly of blood vessels.
May 5, 2010 at 7:51 AM
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| | Fusion of uniluminal vascular spheroids: a model for assembly of blood vessels. Dev Dyn. 2010 Feb;239(2):398-406 Authors: Fleming PA, Argraves WS, Gentile C, Neagu A, Forgacs G, Drake CJ We evaluated the self-assembly properties of uniluminal vascular spheroids having outer layers of vascular smooth muscle cells and a contiguous inner layer of endothelial cells lining a central lumen. We showed that while pairs of uniluminal vascular spheroids suspended in culture medium fused to form a larger diameter spheroidal structure, spheroids in collagen hydrogels formed elongated structures. These findings highlight the potential use of uniluminal vascular spheroids as modules to engineer blood vessels. We also demonstrate that uniluminal vascular spheroid fusion conforms to models describing the coalescence of liquid drops. Furthermore, the fusion of uniluminal vascular spheroids in vitro closely resembled the in vivo process by which the descending aorta forms from the fusion of the paired dorsal aortae during embryonic development. Together, the findings indicate that tissue liquidity underlies uniluminal vascular spheroid fusion and that in vivo anast! omosis of blood vessels may involve a similar mechanism. PMID: 19918756 [PubMed - indexed for MEDLINE] | | |
| [Preparation of whole-kidney acellular matrix in rats by perfusion]
May 5, 2010 at 7:51 AM
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| | [Preparation of whole-kidney acellular matrix in rats by perfusion] Nan Fang Yi Ke Da Xue Xue Bao. 2009 May;29(5):979-82 Authors: Liu CX, Liu SR, Xu AB, Kang YZ, Zheng SB, Li HL OBJECTIVE: To prepare rat whole-kidney acellular matrix (ACM) scaffolds using fluid perfusion method. METHODS: The kidneys with ureters and renal vessels were harvested from 12-week-old Wistar rats. Intravenous catheters were inserted through the renal arteries to establish channels for whole-kidney retrograde perfusion successively with heparinized PBS, 1% SDS, deionized water, 1% TritonX-100 and antibiotic-containing PBS under a pressure of 100 cmH2O. After decellularization, the scaffolds were observed under microscope with HE staining, scanning electron microscope, and fluorescence microscope with DAPI fluorescence staining. RESULTS: No cell residue was found in the scaffolds under microscope. Scanning electron microscope identified reticular structures consisting of basilar membrane and collagen without normal cellular structures in the scaffolds, and no strong fluorescence due to the binding of DAPI to the cell nuclei was observed under fluorescence microsco! pe. CONCLUSION: Fluid perfusion is simple and reliable to prepare rat whole-kidney acellular matrix, which may serve as an ideal cell-free scaffold. PMID: 19460725 [PubMed - indexed for MEDLINE] | | |
| [Mesenchymal stem cells transplanted in mdx mice differentiate into myocytes and express dystrophin/utrophin]
May 5, 2010 at 7:51 AM
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| | [Mesenchymal stem cells transplanted in mdx mice differentiate into myocytes and express dystrophin/utrophin] Nan Fang Yi Ke Da Xue Xue Bao. 2009 May;29(5):974-8 Authors: Feng SW, Zhang C, Lu XL, Liu TY, Li CM, Yao XL, Yu MJ OBJECTIVE: To investigate the differentiation of rat bone marrow mesenchymal stem cells (MSCs) into myocytes and their expression of dystrophin/utrophin after transplantation in mdx mice. METHODS: BrdU-labeled fifth-passage rat MSCs were transplanted in mdx mice with previous total body gamma irradiation (7 Gy). At 4, 8, 12 and 16 weeks after the transplantation, the mice were sacrificed to detect dystrophin/BrdU and utrophin expressions in the gastrocnemius muscle using immunofluorescence assay, RT-PCR and Western blotting. Five normal C57 BL/6 mice and 5 mdx mice served as the positive and negative controls, respectively. RESULTS: Four weeks after MSC transplantation, less than 1% of the muscle fibers of the mdx mice expressed dystrophin, which increased to 15% at 16 weeks. Donor-derived nuclei were detected in both single and clusters of dystrophin-positive fibers. Some BrdU-positive nuclei were centrally located, and some peripherally within myofibers. Utrophi! n expression decreased over time after transplantation. CONCLUSION: The myofibers of mdx mice with MSC transplantation express dystrophin, which is derived partially from the transplanted MSCs. Dystrophin expression from the transplanted MSCs partially inhibits the upregulation of utrophin in mdx mouse muscle, showing a complementary relation between them. PMID: 19460724 [PubMed - indexed for MEDLINE] | | | | 
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