| Low level of O2 inhibits commitment of cultured mesenchymal stromal precursor cells from the adipose tissue in response to osteogenic stimuli.
November 11, 2009 at 9:48 am
|
| | Low level of O2 inhibits commitment of cultured mesenchymal stromal precursor cells from the adipose tissue in response to osteogenic stimuli. Bull Exp Biol Med. 2009 Jun;147(6):760-3 Authors: Grinakovskaya OS, Andreeva ER, Buravkova LB, Rylova YV, Kosovsky GY Mesenchymal stromal precursor cells from human lipoaspirate (lMSC) cultured at 5% O(2) formed 50% less mineralized matrix in response to osteogenic induction than cells cultured under standard conditions (20% O(2)). After lMSC percultured at 5% O(2) were transferred to normoxic conditions (20% O(2)), they produced the same amount of matrix as lMSC permanently cultured at 20% O(2). Hence, hypoxia inhibited the commitment of lMSC under the effect of osteogenic stimuli, which can be important in reparative and regenerative medicine. PMID: 19902077 [PubMed - in process] |
| Cell-free and cell-based approaches for bone regeneration.
November 11, 2009 at 9:48 am
|
| | Cell-free and cell-based approaches for bone regeneration. Nat Rev Rheumatol. 2009 Nov 10; Authors: Bueno EM, Glowacki J The clinical augmentation of bone currently involves the use of autogenous or allogeneic bone grafts and synthetic materials, all of which are associated with limitations. Research on the safe enhancement of bone formation concerns the potential value of scaffolds, stem cells, gene therapy, and chemical and mechanical signals. Optimal scaffolds are engineered to provide mechanical stability while supporting osteogenesis, osteoconduction and/or osteoinduction. Scaffold materials include natural or synthetic polymers, ceramics, and composites. The resorption, mechanical strength and efficacy of these materials can be manipulated through structural and chemical design parameters. Cell-seeded scaffolds contain stem cells or progenitor cells, such as culture-expanded marrow stromal cells and multipotent skeletal progenitor cells sourced from other tissues. Despite extensive evidence from proof-of-principle studies, bone tissue engineering has not translated to clinical practice. Much of the research involves in vitro and animal models that do not replicate potential clinical applications. Problem areas include cell sources and numbers, over-reliance on existing scaffold materials, optimum delivery of factors, control of transgene expression, vascularization, integration with host bone, and the capacity to form bone and marrow structures in vivo. Current thinking re-emphasizes the potential of biomimetic materials to stimulate, enhance, or control bone's innate regenerative capacity at the implantation site. PMID: 19901916 [PubMed - as supplied by publisher] |
| Biological basis for the use of autologous bone marrow stromal cells in the treatment of congenital pseudarthrosis of the tibia.
November 11, 2009 at 9:48 am
|
| | Biological basis for the use of autologous bone marrow stromal cells in the treatment of congenital pseudarthrosis of the tibia. Bone. 2009 Nov 6; Authors: Granchi D, Devescovi V, Baglìo SR, Leonardi E, Donzelli O, Magnani M, Stilli S, Giunti A, Baldini N The study was designed to establish the biological basis for the use of autologous bone-marrow stromal cells (MSC) in order to improve the curing opportunities of congenital pseudarthrosis of the tibia (CPT). The investigation was planned by taking into account that the pathophysiology of bone healing mainly depends on the osteogenic potential of the resident cells, although several factors play a crucial role in restoring the normal bone structure. Bone marrow samples were collected from the lesion site (P) and the iliac crest (IC) of 7 patients affected by CPT and type 1 neurofibromatosis (NF1+) and 6 patients affected by CPT without NF1 (NF1-). Four patients without CPT served as control group. Biochemical, functional and molecular assays showed that the ability to generate bone-forming cells was higher in IC-MSC than in P-MSC, but lower in CPT patients than in control group. We evaluated whether host factors, such as autologous serum and the microenvironment surrounding the pseudarthrosis lesion, could impair the osteogenic differentiation of IC-MSC. Autologous serum was less effective than FBS in promoting the IC-MSC differentiation, but the damage was more evident in NF1- than in NF1+ patients. Additionally, the supernatant of osteoblast cultures obtained from bone fragments close to the lesion site favoured the differentiation of IC-MSC in NF1- patients. In summary, our results suggest that MSC transplantation could be a promising strategy for the therapy of CPT. Further studies are warranted to confirm the clinical effectiveness in comparison to standard surgical treatment. PMID: 19900596 [PubMed - as supplied by publisher] |
| When Cells Become a Drug. Endothelial Progenitor Cells for Cardiovascular Therapy: Aims and Reality.
November 11, 2009 at 9:48 am
|
| | When Cells Become a Drug. Endothelial Progenitor Cells for Cardiovascular Therapy: Aims and Reality. Recent Pat Cardiovasc Drug Discov. 2009 Nov 10; Authors: Burba I, Devanna P, Pesce M The recently disclosed plasticity properties of adult-derived stem cells, their ability to be reprogrammed by defined factors into pluripotent stem cells and the comprehension of "epi"-genetic mechanisms underlying stem cells differentiation process has opened unexpected avenues to attempt regeneration of tissues affected by degenerative disorders and prompted the birth of the new "regenerative medicine" concept. Regeneration of the vascular and myocardial tissues is considered a primary endpoint to limit the consequences of acute and chronic ischemic heart disorders. Cellular therapy of the ischemic heart has been attempted in more than 1000 patients worldwide and the results of the first meta-analysis studies have been recently made available. In several cases, the results did not fulfill the expectations. In fact, they unpredictably indicated modest, yet significant, clinical benefits in patients compared to the outstanding results using stem cells in animal models of ischemic heart and peripheral disease. Several interpretations have been raised to explain these discrepancies. These include lifestyle and risk factor-associated modifications of the stem cell biological activity, but also procedural problems in the translation of cells from bench to bedside. The present review will cover light and shaded areas in the cardiovascular cellular therapy field, and will discuss about recent advances and related patents designed to enhance efficiency of stem cell therapy in patients with cardiovascular disease. These advancements will be discussed in the light of the most advanced issues that have been introduced worldwide by Regulatory Agencies. PMID: 19900162 [PubMed - as supplied by publisher] |
| In vitro response of the bone marrow-derived mesenchymal stem cells seeded in a type-I collagen-glycosaminoglycan scaffold for skin wound repair under the mechanical loading condition.
November 11, 2009 at 9:48 am
|
| | In vitro response of the bone marrow-derived mesenchymal stem cells seeded in a type-I collagen-glycosaminoglycan scaffold for skin wound repair under the mechanical loading condition. Mol Cell Biomech. 2009 Dec;6(4):217-27 Authors: Kobayashi M, Spector M In order to achieve successful wound repair by regenerative tissue engineering using mesenchymal stem cells (MSCs), it is important to understand the response of stem cells in the scaffold matrix to mechanical stress. To investigate the clinical effects of mechanical stress on the behavior of cells in scaffolds, bone marrow-derived mesenchymal stem cells (MSCs) were grown on a type-I collagen-glycosaminoglycan (GAG) scaffold matrix for one week under cyclic stretching loading conditions. The porous collagen-GAG scaffold matrix for skin wound repair was prepared, the harvested canine MSCs were seeded on the scaffold, and cultured under three kinds of cyclic stretching loading conditions (0%: control, 5% strain, 15% strain). After 7 days incubation, MSCs were evaluated histologically and immunohistochemically regarding the proliferation and differentiation. Cultured MSCs in the high strain (15% strain) group showed active alpha-smooth muscle actin (alpha-SMA) expression and poor differentiation into type-I collagen-positive cells, whereas enhanced differentiation into type-I collagen positive cells and a lack of alpha-SMA expression where shown in the lower stress (5% strain) group. These results suggest that mechanical stress may affect the proliferation and differentiation of stem cells, and subsequently the wound healing process, through attachment interactions between the stem cells and scaffold matrix. Our findings provide an additional consideration for clinical treatment of wound repair using regenerative tissue engineering. PMID: 19899445 [PubMed - in process] |
| [Decellularization technology application in whole liver reconstruct biological scaffold]
November 11, 2009 at 9:48 am
|
| | [Decellularization technology application in whole liver reconstruct biological scaffold] Zhonghua Yi Xue Za Zhi. 2009 Apr 28;89(16):1135-8 Authors: Kang YZ, Wang Y, Gao Y OBJECTIVE: To explore an innovative method for preparation of a whole-liver reconstruct scaffold with intact three-dimensional geometry, vasculature and bile duct by decellularization technology. METHODS: The portal vein was annulated and perfused sequentially with 1%Triton X-100 and 1%SDS for about 4 h, and then was perfused with phosphate buffered saline to dilute SDS residue. The retained structure was evaluated by histological analyses, including macroscopic, Hematoxylin-Eosin staining, Masson's trichrome staining, orcein staining and SEM. The liquid polymer preparation 8% - 10%, which was made of chlorinated poly vinyl chloride (CPVC as solute), acetone (as solvent) and pigment, was injected into portal vein and bile duct to demonstrate the integrity of the portal vein and bile duct. The scaffold was cut into slices with the thickness of about 50 microm and cocultured with C3A cell line. RESULTS: Macroscopic examination showed that the decellularized liver was transparent and intrahepatic Glisson's system could be observed. H&E staining of slices of decellularized liver demonstrated no intact cells or nuclei existed. Masson trichrome staining revealed collagen retained. Orcein staining showed that there were elastic fibers. SEM showed the network of ECM was intact. C3A-to-scaffold co-culture revealed the scaffold of good biocompatibility. CONCLUSION: Perfusion with detergents through portal vein for liver decellularization was an efficient method to obtain a completely whole-liver scaffold which can be used for hepatic organ reconstruction. PMID: 19595149 [PubMed - indexed for MEDLINE] |
| [Restoration of segmental bone defect by calcium sulfate pellet: experiment with rabbit]
November 11, 2009 at 9:48 am
|
| | [Restoration of segmental bone defect by calcium sulfate pellet: experiment with rabbit] Zhonghua Yi Xue Za Zhi. 2009 Mar 24;89(11):777-81 Authors: Cui X, Zhang BX, Zhao DW OBJECTIVE: To compare the effects of different calcium sulfate pellets made by different methods in treating segmental defect of bone. METHODS: Eighty New Zealand white rabbits underwent cutting off a segment in the middle part of radius so as to establish models of radial segmental defect, and than were divided into 4 groups: Group A as control group, Group B with calcium sulfate pellet made by routine method implanted into the defect, Group C with chitosan coated pressed calcium sulfate pellet implanted into the defect, and Group D with chitosan coated pressed calcium sulfate pellet combined with recombinant human bone morphogenetic protein (rhBMP)-2 implanted into the defect: X-ray photography was done every 4 weeks to observe the new bone formation. Four, 8, and 12 weeks 5 rabbits from each group were killed. The defect segments with parts of normal bone at both ends were cut off to undergo fluorescence microscopy and biomechanic three point bending test. RESULTS: X-ray photography and histological examination showed that new bone formation of cortex and reconstruction of marrow cavity were seen in Groups D and C, especially in Group D. The new bone mineralization rate of Group D was significantly higher than that of Group C (P<0.05) which was significantly higher than that of Group B (P<0.01). The anti-bending strength ratio of Group D was (47.5%+/-2.1%, significantly higher than that of Group C [(39.6+/-1.7)%, F=125.3, P<0.01], and the anti-bending strength ratios of Groups D and C were both significantly higher than those of Groups B and A [(23.6+/-3.3)% and (21.3+/-2.7)%]. CONCLUSION: Chitosan coated pressed calcium sulfate pellet shows relatively higher anti-bending strength and slightly slower resorption that closely coincide with the growth rate of new bone. It can be used to restore segmental bone defect, and particularly when combined with rhBMP-2. PMID: 19595109 [PubMed - indexed for MEDLINE] |
| Comparative study of silk fibroin porous scaffolds derived from salt/water and sucrose/hexafluoroisopropanol in cartilage formation.
November 11, 2009 at 9:48 am
|
| | Comparative study of silk fibroin porous scaffolds derived from salt/water and sucrose/hexafluoroisopropanol in cartilage formation. J Biosci Bioeng. 2009 Jul;108(1):68-75 Authors: Makaya K, Terada S, Ohgo K, Asakura T The purpose of this study is to create a new silk fibroin scaffold with sufficient three-dimensional morphology and porous structure for cartilage formation. We have applied sucrose particles sized around 300 to 500 microm as porogens compared to equal-sized salt particles. After the porogen was leached out with water, scaffolds were prepared with fibroin derived from sucrose/hexafluoroisopropanol (Su/H) or salt/water (Sa/W) based composites. A compression test indicated that the Sa/W fibroin was much harder than the Su/H fibroin, but a protease enzyme digested the Sa/W fibroin more quickly than Su/H fibroin. Rabbit ear chondrocytes were seeded onto the scaffolds for 4-8 week in vitro culture and histological analyses were performed. The distribution of cartilage formation in Safranin O staining was more homogenous in Su/H fibroin than that of Sa/W fibroin. The overall amount of cartilage was significantly better in the Su/H fibroin than that in the Sa/W fibroin. However, the inner structure of pore wall in the Sa/W fibroin was rough and microporous with cartilage matrix deposition, while that in the Su/H fibroin was thin and homogenous. Since mature cartilage gradually regenerates to fill the porous space, slowly degradable Su/H fibroin should be a better candidate for cartilage formation. PMID: 19577196 [PubMed - indexed for MEDLINE] |
| Bili inhibits Wnt/beta-catenin signaling by regulating the recruitment of axin to LRP6.
November 11, 2009 at 9:48 am
|
| | Bili inhibits Wnt/beta-catenin signaling by regulating the recruitment of axin to LRP6. PLoS One. 2009;4(7):e6129 Authors: Kategaya LS, Changkakoty B, Biechele T, Conrad WH, Kaykas A, Dasgupta R, Moon RT BACKGROUND: Insights into how the Frizzled/LRP6 receptor complex receives, transduces and terminates Wnt signals will enhance our understanding of the control of the Wnt/ss-catenin pathway. METHODOLOGY/PRINCIPAL FINDINGS: In pursuit of such insights, we performed a genome-wide RNAi screen in Drosophila cells expressing an activated form of LRP6 and a beta-catenin-responsive reporter. This screen resulted in the identification of Bili, a Band4.1-domain containing protein, as a negative regulator of Wnt/beta-catenin signaling. We found that the expression of Bili in Drosophila embryos and larval imaginal discs significantly overlaps with the expression of Wingless (Wg), the Drosophila Wnt ortholog, which is consistent with a potential function for Bili in the Wg pathway. We then tested the functions of Bili in both invertebrate and vertebrate animal model systems. Loss-of-function studies in Drosophila and zebrafish embryos, as well as human cultured cells, demonstrate that Bili is an evolutionarily conserved antagonist of Wnt/beta-catenin signaling. Mechanistically, we found that Bili exerts its antagonistic effects by inhibiting the recruitment of AXIN to LRP6 required during pathway activation. CONCLUSIONS: These studies identify Bili as an evolutionarily conserved negative regulator of the Wnt/beta-catenin pathway. PMID: 19572019 [PubMed - indexed for MEDLINE] |
| The phosphorylation of vascular endothelial growth factor receptor-2 (VEGFR-2) by engineered surfaces with electrostatically or covalently immobilized VEGF.
November 11, 2009 at 9:48 am
|
| | The phosphorylation of vascular endothelial growth factor receptor-2 (VEGFR-2) by engineered surfaces with electrostatically or covalently immobilized VEGF. Biomaterials. 2009 Sep;30(27):4618-28 Authors: Anderson SM, Chen TT, Iruela-Arispe ML, Segura T Growth factors are a class of signaling proteins that direct cell fate through interaction with cell-surface receptors. Although a myriad of possible cell fates stems from a growth factor binding to its receptor, the signaling cascades that result in one fate over another are still being elucidated. One possible mechanism by which nature modulates growth factor signaling is through the method of presentation of the growth factor--soluble or immobilized (matrix bound). Here we present the methodology to study signaling of soluble versus immobilized VEGF through VEGFR-2. We have designed a strategy to covalently immobilize VEGF using its heparin-binding domain to orient the molecule (bind) and a secondary functional group to mediate covalent binding (lock). This bind-and-lock approach aims to allow VEGF to assume a bioactive orientation before covalent immobilization. Surface plasmon resonance (SPR) demonstrated heparin and VEGF binding with surface densities of 60 ng/cm2 and 100 pg/cm2, respectively. ELISA experiments confirmed VEGF surface density and showed that electrostatically bound VEGF releases in cell medium and heparin solutions while covalently bound VEGF remains immobilized. Electrostatically bound VEGF and covalently bound VEGF phosphorylate VEGFR-2 in both VEGFR-2 transfected cells and VEGFR-2 endogenously producing cells. HUVECs plated on VEGF functionalized surfaces showed different morphologies between surface-bound VEGF and soluble VEGF. The surfaces synthesized in these studies allow for the study of VEGF/VEGFR-2 signaling induced by covalently bound, electrostatically bound, and soluble VEGF and may provide further insight into the design of materials for the generation of a mature and stable vasculature. PMID: 19540581 [PubMed - indexed for MEDLINE] |
| Engineering liver tissue spheroids with inverted colloidal crystal scaffolds.
November 11, 2009 at 9:48 am
|
| | Engineering liver tissue spheroids with inverted colloidal crystal scaffolds. Biomaterials. 2009 Sep;30(27):4687-94 Authors: Lee J, Cuddihy MJ, Cater GM, Kotov NA Multicellular spheroids provide a new three-dimensional (3D) level of control over morphology and function of ex vivo cultured tissues. They also represent a valuable experimental technique for drug discovery and cell biology. Nevertheless, the dependence of many cellular processes on the cluster diameter remains unclear. To provide a tool for the systematic evaluation of such dependences, we introduce here inverted colloidal crystal (ICC) scaffolds. Uniformly sized pores in ICC cell matrixes afford a high yield production of controlled size spheroids in standard 96 well-plates. Transparent hydrogel matrix and ship-in-bottle effect also allows for convenient monitoring of cell processes by traditional optical techniques. Different developmental stages of 46.5-151.6 microm spheroids from HepG2 hepatocytes with vivid morphological similarities to liver tissue (bile canaliculi) were observed. The liver-specific functions of HepG2 cells were systematically investigated and compared for spheroids of different diameters as well as 2D cultures. Clear trends of albumin production and CYP450 activity were observed; diffusion processes and effect of cellular aggregation on metabolic activity were identified to be the primary contributors to the size dependence of the liver functions in HepG2 spheroids in ICC scaffolds. Since the aggregation of cells into clusters is a universal biological process, these findings and scaffolds can be applied to many other relevant cell types. PMID: 19524294 [PubMed - indexed for MEDLINE] |
| Immunoarchitectural characterization of a human skin model reconstructed in vitro.
November 11, 2009 at 9:48 am
|
| | Immunoarchitectural characterization of a human skin model reconstructed in vitro. Sao Paulo Med J. 2009 Jan;127(1):28-33 Authors: Souto LR, Vassallo J, Rehder J, Pinto GA, Puzzi MB CONTEXT AND OBJECTIVE: Over the last few years, different models for human skin equivalent reconstructed in vitro (HSERIV) have been reported for clinical usage and applications in research for the pharmaceutical industry. Before release for routine use as human skin replacements, HSERIV models need to be tested regarding their similarity with in vivo skin, using morphological (architectural) and immunohistochemical (functional) analyses. A model for HSERIV has been developed in our hospital, and our aim here was to further characterize its immunoarchitectural features by comparing them with human skin, before it can be tested for clinical use, e.g. for severe burns or wounds, whenever ancillary methods are not indicated. DESIGN AND SETTING: Experimental laboratory study, in the Skin Cell Culture Laboratory, School of Medical Sciences, Universidade Estadual de Campinas. METHODS: Histological sections were stained with hematoxylin-eosin, Masson's trichrome for collagen fibers, periodic acid-Schiff reagent for basement membrane and glycogen, Weigert-Van Gieson for elastic fibers and Fontana-Masson for melanocytes. Immunohistochemistry was used to localize cytokeratins (broad spectrum of molecular weight, AE1/AE3), high molecular weight cytokeratins (34betaE12), low molecular weight cytokeratins (35betaH11), cytokeratins 7 and 20, vimentin, S-100 protein (for melanocytic and dendritic cells), CD68 (KP1, histiocytes) and CD34 (QBend, endothelium). RESULTS: Histology revealed satisfactory similarity between HSERIV and in vivo skin. Immunohistochemical analysis on HSERIV demonstrated that the marker pattern was similar to what is generally present in human skin in vivo. CONCLUSION: HSERIV is morphologically and functionally compatible with human skin observed in vivo. PMID: 19466292 [PubMed - indexed for MEDLINE] |
| Culture conditions shape mesenchymal stromal cell phenotype and function.
November 11, 2009 at 9:48 am
|
| | Culture conditions shape mesenchymal stromal cell phenotype and function. Cytotherapy. 2009;11(2):101-2 Authors: Horwitz EM PMID: 19301168 [PubMed - indexed for MEDLINE] |
| Basic research and clinical applications of non-hematopoietic stem cells, 4-5 April 2008, Tubingen, Germany.
November 11, 2009 at 9:48 am
|
| | Basic research and clinical applications of non-hematopoietic stem cells, 4-5 April 2008, Tubingen, Germany. Cytotherapy. 2009;11(2):245-55 Authors: Schäfer R, Dominici M, Müller I, Horwitz E, Asahara T, Bulte JW, Bieback K, Le Blanc K, Bühring HJ, Capogrossi MC, Dazzi F, Gorodetsky R, Henschler R, Handgretinger R, Kajstura J, Kluger PJ, Lange C, Luettichau I, Mertsching H, Schrezenmeier H, Sievert KD, Strunk D, Verfaillie C, Northoff H From 4 to 5 April 2008, international experts met for the second time in Tubingen, Germany, to present and discuss the latest proceedings in research on non-hematopoietic stem cells (NHSC). This report presents issues of basic research including characterization, isolation, good manufacturing practice (GMP)-like production and imaging as well as clinical applications focusing on the regenerative and immunomodulatory capacities of NHSC. PMID: 19152153 [PubMed - indexed for MEDLINE] |
| Novel apatite fiber scaffolds can promote three-dimensional proliferation of osteoblasts in rodent bone regeneration models.
November 11, 2009 at 9:48 am
|
| | Novel apatite fiber scaffolds can promote three-dimensional proliferation of osteoblasts in rodent bone regeneration models. J Biomed Mater Res A. 2009 Sep 1;90(3):811-8 Authors: Morisue H, Matsumoto M, Chiba K, Matsumoto H, Toyama Y, Aizawa M, Kanzawa N, Fujimi TJ, Uchida H, Okada I We have successfully synthesized hydroxyapatite fibers via a homogenous precipitation method. Using these hydroxyapatite fibers, we have produced the apatite fiber scaffolds (AFS) with well-controlled pore sizes (porosity above 95%). The AFS is relatively simple to synthesize, and its porosity and pore size are controllable. The usefulness of AFS as a scaffold for bone regeneration was evaluated by (1) seeding and culturing cells in the AFS in vitro, (2) implanting the AFS seeded with cells inside the subcutaneous tissue of mice. The AFS had biocompatibility to support cell adhesion, proliferation, and differentiation. Ectopic bone formation could be formed in the AFS at 12 weeks after implantation into the subcutaneous tissue. Because of its high interpore connection, pore diameters, and porosity, it was believed that AFS was an effective scaffold that provided a three-dimensional cell culture environment. In both in vitro and in vivo environments, the more porous AFS was more advantageous in cell proliferation, cell adhesion, proliferating capacity, robust cell differentiation, ultimately inducing bone ingrowth inside the scaffolds. PMID: 18615469 [PubMed - indexed for MEDLINE] |
| Cellular responses to degradable cyclic acetal modified PEG hydrogels.
November 11, 2009 at 9:48 am
|
| | Cellular responses to degradable cyclic acetal modified PEG hydrogels. J Biomed Mater Res A. 2009 Sep 1;90(3):863-73 Authors: Kaihara S, Matsumura S, Fisher JP In this study, high viability of bone marrow stromal stem cells (BMSCs) encapsulated in a synthetic, poly[poly(ethylene glycol)-co-cyclic acetal] (PECA) hydrogel has been reported. This novel degradable hydrogel, which contains cyclic acetal as degradable segments and poly(ethylene glycol) (PEG) as hydrophilic segments, has been designed to limit the release of acidic products during hydrolytic degradation. PECAs with three different molecular weights (PECA 600, 1000, and 2000) were prepared to evaluate the effect of polymer main chain molecular weight on the viability and morphology of BMSCs embedded in PECA hydrogels as well as the viability of BMSCs exposed to PECA degradation products. Results demonstrated high BMSC viability when incubated in control media with PECA, while a significant decrease in viability was noted after 4 days when incubated in media augmented with PEG diacrylate. There was no effect of PECA molecular weight on the differentiation and cytotoxicity of degradation products up to 4 days, indicating that the degradation products' terminal carbonyl groups do not significantly affect cell viability and differentiation. BMSC viability when embedded on PECA hydrogels was evaluated by a LIVE/DEAD assay, and confirmed high viability up to 14 days. Gene expression analysis confirmed that BMSCs embedded in PECA hydrogels undergo osteogenic differentiation. Histological analysis also showed that cell morphology was significantly influenced by hydrogel swelling degree, which is itself controllable by the molecular weights of PECA main chains. These results indicate that PECA hydrogels may be utilized as scaffolds for regeneration of bone-like tissues. PMID: 18615467 [PubMed - indexed for MEDLINE] | | | 
|
No comments:
Post a Comment