|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | | Studies in adipose-derived stromal cells: migration and participation in repair of cranial injury after systemic injection. Plast Reconstr Surg. 2011 Mar;127(3):1130-40 Authors: Levi B, James AW, Nelson ER, Hu S, Sun N, Peng M, Wu J, Longaker MT Adipose-derived stromal cells are a multipotent cell type with the ability to undergo osteogenic differentiation. The authors sought to examine whether systemically administered adipose-derived stromal cells would migrate to and heal surgically created defects of the mouse cranial skeleton. PMID: 21364416 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Acute skeletal injury is necessary for human adipose-derived stromal cell-mediated calvarial regeneration. Plast Reconstr Surg. 2011 Mar;127(3):1118-29 Authors: Levi B, James AW, Nelson ER, Peng M, Wan DC, Commons GW, Lee M, Wu B, Longaker MT Studies have demonstrated that human adipose-derived stromal cells (ASCs) are able to repair acute calvarial injuries. The more clinically relevant repair of an established skeletal defect, however, has not been addressed. The authors sought to determine whether human ASCs could heal chronic (established) calvarial defects. PMID: 21364415 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Mesenchymal stem cell therapy for knee osteoarthritis. Preliminary report of four patients. Int J Rheum Dis. 2011 May;14(2):211-5 Authors: Davatchi F, Abdollahi BS, Mohyeddin M, Shahram F, Nikbin B Background: Osteoarthritis (OA) is a cartilage degenerative process, involving the immune system, producing local inflammatory reactions, with production of pro-inflammatory cytokines and metalloproteinases. No treatment is still available to improve or reverse the process. Stem cell therapy opened new horizons for treatment of many incurable diseases. Mesenchymal stem cells (MSCs) due to their multi-lineage potential, immunosuppressive activities, limited immunogenicity and relative ease of growth in culture, have attracted attentions for clinical use. Aim: The aim of this study was to examine whether MSC transplantation could reverse the OA process in the knee joint. The project was approved by the Tehran University of Medical Sciences Research Committee and Ethical Committee. Patients and Methods: Four patients with knee osteoarthritis were selected for the study. They were aged 55, 57, 65 and 54 years, and had moderate to severe knee OA. After their signed written consent, 30 mL of bone marrow were taken and cultured for MSC growth. After having enough MSCs in culture (4-5 weeks) and taking in consideration all safety measures, cells were injected in one knee of each patient. Results: The walking time for the pain to appear improved for three patients and remained unchanged for one. The number of stairs they could climb and the pain on visual analog scale improved for all of them. On physical examination, the improvement was mainly for crepitus. It was minor for the improvement of the range of motion. Conclusion: Results were encouraging, but not excellent. Improvement of the technique may improve the results. PMID: 21518322 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Selecting the optimal cell for kidney regeneration: Fetal, adult or reprogrammed stem cells. Organogenesis. 2011 Apr 1;7(2) Authors: Harari-Steinberg O, Pleniceanu O, Dekel B Chronic kidney disease (CKD) is a progressive loss in renal function over a period of months or years. End-stage renal disease (ESRD) or stage 5 CKD ensues when renal function deteriorates to under 15% of the norm. ESRD requires either dialysis or preferentially a kidney organ allograft, which is severely limited due to organ shortage for transplantation. To combat this situation one needs to either increase supply of organs or decrease for their demand. Two strategies therefore exist: for those that have completely lost their kidney function (ESRD) we will need to device new kidneys. Taking into account the kidneys extremely complex structure this may prove to be impossible in the near future. In contrast, for those patients which are in the slow progression route from CKD into ESRD but still have functional kidneys we might be able to halt progression by introducing stem cell therapy to diseased kidneys to rejuvenate or regenerate individual cell types. Multiple cell compartments which fall into three categories are likely to be worthy targets for cell repair: vessels, stroma (interstitium) and nephron epithelia. Different stem/progenitor cells can be linked to regeneration of specific cell types. Others and we have shown that hematopoietic progenitors and hemangioblastic cell types have direct effects on the vascular/interstitial niche. In addition, multipotent stromal cells (MSC) whether derived from the bone marrow or isolated from the kidney's non-tubular compartment may in turn heal nephron epithelia via paracrine mechanisms. Nevertheless, as we now know that all of the above lack nephrogenic potential we should continue our quest to derive genuine nephron (epithelial) progenitors from differentiated pluripotent stem cells, from fetal and adult kidneys and even from directly reprogrammed somatic cells. PMID: 21519195 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Viable Cryopreserving Tissue-Engineered Cell-Biomaterial for Cell Banking Therapy in an Effective Cryoprotectant. Tissue Eng Part C Methods. 2011 Apr 25; Authors: Umemura E, Yamada Y, Nakamura S, Ito K, Hara K, Ueda M The application of cell-biomaterial systems in tissue engineering and regenerative medicine is an important challenge in biomedicine, which preserves not only cells, but also tissue-engineered constructs. In this study, the constructs and cryoprotectant parameters were optimized, and it was evaluated whether the characteristics of dental pulp stem cells (DPSCs), which have high proliferation ability as stem cells, were maintained during encapsulation and cryopreservation. The optimal cell-biomaterial gel constructs with the gelation rate of 2% alginate: 100 mM CaCO(3): 200 mM glucono-δ-lactone (GDL)=4:1:1 and suitable cryoprotectants (CPAs) used for cryopreservation were Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% ethylene glycol (EG), 1.0 M sucrose and 0.00075 M polyvinylpyrrolidone (PVP). Optimality was confirmed by cell viability (trypan blue, live/dead analysis), the proliferation of DPSCs, and the microstructure using scanning electron microscopy (SEM) in the constructs, and surface epitope by flow cytometric analysis before and after cryopreservation. There were no visible differences in the structure. In conclusion, this study indicates that the optimal cell-biomaterial gel constructs and the cryoprotectant are promising biomaterials. The defined encapsulation/thawing system offers an excellent option for cell-banking therapy to be developed with ready-to-use viable biomaterials and patient-specific products as drug delivery systems. PMID: 21517691 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Continuous cyclic mechanical tension inhibited Runx2 expression in mesenchymal stem cells through RhoA-ERK1/2 pathway. J Cell Physiol. 2011 Aug;226(8):2159-69 Authors: Shi Y, Li H, Zhang X, Fu Y, Huang Y, Lui PP, Tang T, Dai K Tensile load is known to regulate the osteogenesis of mesenchymal stem cells (MSCs) and osteogenic progenitors; therefore it is widely used in clinical treatment and tissue engineering. Meanwhile, in vitro, both published studies and our lab data demonstrate that the application of intermittent tensile loading which stimulates cells several minutes or hours each day for several days has promoted the osteogenic differentiation of MSCs. Whereas, for clinic trails, it is important to know accurately how and how long mechanical tension should be applied. Hence, it is necessary to investigate different kinds of mechanical tension on osteogenesis of MSCs. Until now, during the osteogenesis, there has been no research on the effect of continuous cyclic mechanical tension (CCMT) which provides continuous stimulation throughout the study period. We firstly figure out CCMT inhibiting the expression of osteogenic genes such as key transcription factor Runx2. It is known that RhoA regulates cell differentiation in response to mechanical stimuli. MAPK signaling acts as a downstream effector of RhoA. So, we ask in MSCs, if CCMT regulates the osteogenic master gene Runx2 through RhoA-ERK1/2 pathway. And then, we find out there is a decrease in RhoA activity after CCMT stimulation. Pre-treatment of CCMT-loaded MSCs with LPA, a RhoA activator, restores ALP activity and significantly rescues Runx2 expression, while pre-treatment with C3 toxin, a RhoA inhibitor, further decreases the activity of ALP and down-regulates the expression of Runx2. Following results indicate that the inhibition of Runx2 expression after CCMT stimulation is mediated by RhoA-ERK1/2 pathway. J. Cell. Physiol. 226: 2159-2169, 2011. © 2010 Wiley-Liss, Inc. PMID: 21520068 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | A Poly(acrylic acid)-block-Poly(L-glutamic acid) Diblock Copolymer with Improved Cell Adhesion for Surface Modification. Macromol Biosci. 2011 Apr 26; Authors: Cao B, Yan S, Zhang K, Song Z, Cao T, Chen X, Cui L, Yin J A novel PAA-b-PLGA diblock copolymer is synthesized and characterized that has excellent cell adhesion and biocompatibility. Fluorescent DiO labeling is used to monitor the attachment and growth of hASCs on the film surface, and cell proliferation over time is studied. Results show that PLLA modified by a CS/PAA-b-PLGA multilayer film can promote the attachment of human hASCs and provide an advantageous environment for their proliferation. The multilayer film presents excellent biocompatibility and cell adhesive properties, which will provide a new choice for improving the cell attachment in surface modification for tissue engineering. Hydroxyl, carboxyl and amine groups in the CS/PAA-b-PLGA multilayer film may be combined with drugs and growth factors for therapy and differentiation. PMID: 21520504 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | [Heterogeneity of Mesenchymal Stem Cells in Culture In Vitro.] Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2011 Mar;19(2):542-545 Authors: Li YZ, Bao YY, Guo ZK Mesenchymal stem cells (MSC) are the ideal adult stem cells in cell/gene therapy and tissue engineering for their features of easily-handling, highly proliferative capacity in vitro, low immunogenicity and immunomodulatory ability. MSC, as a kind of cellular drug, have been utilized in a phase III clinical trial to treat refractory graft-versus-host disease (GVHD). However, the essences of MSC in culture remain elusive so far. Whether the cells expanded in vitro are stem cells per se, and if not, why expanded MSC maintain their multiple differentiation ability? And are the MSC cultivated in vitro homogeneous and if not, what the heterogeneity stands for? Focusing on the heterogeneity of MSC in culture in vitro, the above questions are briefly discussed in this review. PMID: 21518526 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Chitosan Scaffolds Containing Hyaluronic Acid for Cartilage Tissue Engineering. Tissue Eng Part C Methods. 2011 Apr 25; Authors: Correia CR, Moreira-Teixeira LS, Moroni L, Reis RL, Van Blitterswijk CA, Karperien M, Mano JF Scaffolds derived from natural polysaccharides are very promising in tissue engineering applications and regenerative medicine, as they resemble glycosaminoglycans in the extracellular matrix (ECM). In this study, we have prepared freeze-dried composite scaffolds of chitosan (CHT) and hyaluronic acid (HA) in different weight ratios containing either no HA (control) or 1%, 5%, or 10% of HA. We hypothesized that HA could enhance structural and biological properties of CHT scaffolds. To test this hypothesis, physicochemical and biological properties of CHT/HA scaffolds were evaluated. Scanning electron microscopy micrographs, mechanical properties, swelling tests, enzymatic degradation, and Fourier transform infrared (FTIR) chemical maps were performed. To test the ability of the CHT/HA scaffolds to support chondrocyte adhesion and proliferation, live-dead and MTT assays were performed. Results showed that CHT/HA composite scaffolds are noncytotoxic and promote cell adhesion. ECM formation was further evaluated with safranin-O and alcian blue staining methods, and glycosaminoglycan and DNA quantifications were performed. The incorporation of HA enhanced cartilage ECM production. CHT/5HA had a better pore network configuration and exhibited enhanced ECM cartilage formation. On the basis of our results, we believe that CHT/HA composite matrixes have potential use in cartilage repair. PMID: 21517692 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Engineered silk fibroin protein 3D matrices for in vitro tumor model. Biomaterials. 2011 Mar;32(8):2149-59 Authors: Talukdar S, Mandal M, Hutmacher DW, Russell PJ, Soekmadji C, Kundu SC 3D in vitro model systems that are able to mimic the in vivo microenvironment are now highly sought after in cancer research. Antheraea mylitta silk fibroin protein matrices were investigated as potential biomaterial for in vitro tumor modeling. We compared the characteristics of MDA-MB-231 cells on A. mylitta, Bombyx mori silk matrices, Matrigel, and tissue culture plates. The attachment and morphology of the MDA-MB-231 cell line on A. mylitta silk matrices was found to be better than on B. mori matrices and comparable to Matrigel and tissue culture plates. The cells grown in all 3D cultures showed more MMP-9 activity, indicating a more invasive potential. In comparison to B. mori fibroin, A. mylitta fibroin not only provided better cell adhesion, but also improved cell viability and proliferation. Yield coefficient of glucose consumed to lactate produced by cells on 3D A. mylitta fibroin was found to be similar to that of cancer cells in vivo. LNCaP prostate cancer cells were also cultured on 3D A. mylitta fibroin and they grew as clumps in long term culture. The results indicate that A. mylitta fibroin scaffold can provide an easily manipulated microenvironment system to investigate individual factors such as growth factors and signaling peptides, as well as evaluation of anticancer drugs. PMID: 21167597 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Differential effect of ECM molecules on re-expression of cartilaginous markers in near quiescent human chondrocytes. J Cell Physiol. 2011 Aug;226(8):1981-8 Authors: Chiu LH, Chen SC, Wu KC, Yang CB, Fang CL, Lai WF, Tsai YH The limited source of healthy primary chondrocytes restricts the clinical application of tissue engineering for cartilage repair. Therefore, method to maintain or restore the chondrocyte phenotype during in vitro expansion is essential. The objective of this study is to establish the beneficial effect of ECM molecules on restoring the re-expression of cartilaginous markers in primary human chondrocytes after extensive monolayer expansion. During the course of chondrocyte serial expansion, COL2A1, SOX9, and AGN mRNA expression levels, and GAG accumulation level were reduced significantly in serially passaged cells. Exogenous type II collagen dose-dependently elevated GAG level and induced the re-expression of cartilaginous marker mRNAs in P7 chondrocytes. Chondroitin sulfate did not show significant effect on P7 chondrocytes, while hyaluronic acid inhibited the expression of SOX9 and AGN mRNAs. Upon treatment with type II collagen, FAK, ERK1/2, and JNK were activated via phosphorylation in P7 chondrocytes within 15 min. Furthermore, GFOGER integrin blocking peptide, MEK inhibitor and JNK inhibitor, not p38 inhibitor, significantly reduced the type II collagen-induced GAG deposition level. Finally, in the presence of TGF-β1 and IGF-I, P7 chondrocytes cultured in 3D type II collagen matrix exhibited better cartilaginous features than those cells cultured in the type I collagen matrix. In conclusion, type II collagen alone can effectively restore cartilaginous features of expanded P7 human chondrocytes. It is probably mediated via the activation of FAK-ERK1/2 and FAK-JNK signaling pathways. The potential application of type II collagen in expanding a scarcity of healthy chondrocytes in vitro for further tissue engineering is implicated. J. Cell. Physiol. 226: 1981-1988, 2011. © 2010 Wiley-Liss, Inc. PMID: 21520049 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Dental pulp tissue engineering. Braz Dent J. 2011;22(1):3-13 Authors: Demarco FF, Conde MC, Cavalcanti BN, Casagrande L, Sakai VT, Nör JE Dental pulp is a highly specialized mesenchymal tissue that has a limited regeneration capacity due to anatomical arrangement and post-mitotic nature of odontoblastic cells. Entire pulp amputation followed by pulp space disinfection and filling with an artificial material cause loss of a significant amount of dentin leaving as life-lasting sequelae a non-vital and weakened tooth. However, regenerative endodontics is an emerging field of modern tissue engineering that has demonstrated promising results using stem cells associated with scaffolds and responsive molecules. Thereby, this article reviews the most recent endeavors to regenerate pulp tissue based on tissue engineering principles and provides insightful information to readers about the different aspects involved in tissue engineering. Here, we speculate that the search for the ideal combination of cells, scaffolds, and morphogenic factors for dental pulp tissue engineering may be extended over future years and result in significant advances in other areas of dental and craniofacial research. The findings collected in this literature review show that we are now at a stage in which engineering a complex tissue, such as the dental pulp, is no longer an unachievable goal and the next decade will certainly be an exciting time for dental and craniofacial research. PMID: 21519641 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Standardization of Automated Cell-Based Protocols for Toxicity Testing of Biomaterials. J Biomol Screen. 2011 Apr 25; Authors: Ferreira MV, Jahnen-Dechent W, Neuss S Advances in high-throughput screening (HTS) instrumentation have led to enormous reduction of costs (e.g., of pipetting stations) and to the development of smaller instruments for automation of day-to-day routines in small research laboratories. In the biomaterials community, there has been an increasing interest for standardized screening protocols to identify cell type-specific cytocompatible biomaterials suitable for tissue engineering (TE) applications. In this study, the authors established a multiplexed assay protocol for toxicity screening of biomaterials using a low- to medium-throughput robotic liquid handling station (LHS). The protocol contains analysis of viability, cytotoxicity, and apoptosis combined in one assay. This study includes performance results of a side-by-side comparison of the EpMotion 5070 LHS and conventional pipetting/dispensing systems. Critical parameters were optimized each for a given platform. Higher accuracy and reproducibility were achieved for LHS compared to manually treated samples. The practicability and accuracy of the method in a typical small laboratory setting were tested by running daily routine tasks by trained and untrained laboratory staff. in addition, advantages and disadvantages as well as the step-by-step application protocol are reported. the approach described provides a potential utility in screening biomaterials toxicity, allowing researchers to meet the needs of low- and medium-throughput laboratories. PMID: 21518824 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Frontiers in Research: Chronic Kidney Diseases: The pivotal role of pericytes in kidney fibrosis. Clin Exp Pharmacol Physiol. 2011 Apr 25; Authors: Kida Y, Duffield JS Kidney pericytes were recently identified as collagen-Iα1 producing cells in healthy kidney, but the developmental, physiological and pathological roles of kidney pericytes remain poorly understood. Pericytes are stromal-derived cells that envelop, and have intimate connections with adjacent capillary endothelial cells (ECs). Recent studies in eye and brain have revealed that pericytes are crucial for angiogenesis, vascular stability and vessel integrity. In response to kidney injury, pericytes promptly migrate away from the capillary wall into the interstitial space. Here, pericytes are activated and differentiate into scar-forming myofibroblasts. In the absence of pericytes, peritubular capillaries are destabilized leading to vascular regression. Consequently, capillary loss and fibrosis following kidney injury are intimately linked and hinge centrally around pericyte detachment from ECs. Kinetic mathematical modeling demonstrated that pericytes are the major source of myofibroblasts in fibrotic kidney. Comprehensive genetic fate mapping studies of nephron epithelia or kidney stroma has demonstrated that epithelial cells do not migrate outside of epithelial compartment to become myofibroblasts rather that interstitial pericytes are progenitors of scar-forming myofibroblasts. Bidirectional signaling between pericytes and ECs is necessary for pericyte detachment from peritubular capillaries. In the present review, we summarize the pathologically vital roles of kidney pericytes in fibrosis including our new findings. The study of kidney pericytes and endothelial-pericyte crosstalk will identify novel therapeutic targets for currently incurable chronic kidney diseases. PMID: 21517936 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | The role of PI3K/protein kinase B (PKB/c-akt) in migration and homing of hematopoietic stem and progenitor cells. Curr Opin Hematol. 2011 Apr 23; Authors: Buitenhuis M PURPOSE OF REVIEW: Hematopoietic stem cell (HSC) transplantation is the most powerful treatment modality for a variety of hematological disorders. Successful hematopoietic recovery after transplantation depends on optimal homing of HSCs to the bone marrow and subsequent lodging in the HSC niche. The molecular mechanisms underlying bone marrow homing are, thus far, incompletely understood. This review focuses on recent studies that extended our understanding of how the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (PKB/c-akt) signaling module can regulate migration and homing of HSCs. RECENT FINDINGS: In addition to regulation of HSC maintenance and lineage development, it has recently become apparent that the PI3K/PKB signaling module plays a critical role in regulation of migration and adhesion of hematopoietic stem and progenitor cells. Activation of this signaling pathway enhances firm adhesion, reduces migration and inhibits bone marrow homing, whereas inhibition of PKB conversely induces bone marrow homing. SUMMARY: These findings clearly implicate the PI3K/PKB signaling module in playing a critical role in regulation of bone marrow homing, suggesting that pharmacological modulation of this signaling molecule prior to transplantation may provide a clinical means of improving engraftment levels and accelerating hematopoietic recovery. PMID: 21519240 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Viable Cryopreserving Tissue-Engineered Cell-Biomaterial for Cell Banking Therapy in an Effective Cryoprotectant. Tissue Eng Part C Methods. 2011 Apr 25; Authors: Umemura E, Yamada Y, Nakamura S, Ito K, Hara K, Ueda M The application of cell-biomaterial systems in tissue engineering and regenerative medicine is an important challenge in biomedicine, which preserves not only cells, but also tissue-engineered constructs. In this study, the constructs and cryoprotectant parameters were optimized, and it was evaluated whether the characteristics of dental pulp stem cells (DPSCs), which have high proliferation ability as stem cells, were maintained during encapsulation and cryopreservation. The optimal cell-biomaterial gel constructs with the gelation rate of 2% alginate: 100 mM CaCO(3): 200 mM glucono-δ-lactone (GDL)=4:1:1 and suitable cryoprotectants (CPAs) used for cryopreservation were Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% ethylene glycol (EG), 1.0 M sucrose and 0.00075 M polyvinylpyrrolidone (PVP). Optimality was confirmed by cell viability (trypan blue, live/dead analysis), the proliferation of DPSCs, and the microstructure using scanning electron microscopy (SEM) in the constructs, and surface epitope by flow cytometric analysis before and after cryopreservation. There were no visible differences in the structure. In conclusion, this study indicates that the optimal cell-biomaterial gel constructs and the cryoprotectant are promising biomaterials. The defined encapsulation/thawing system offers an excellent option for cell-banking therapy to be developed with ready-to-use viable biomaterials and patient-specific products as drug delivery systems. PMID: 21517691 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Oxidative stress status accompanying diabetic bladder cystopathy results in the activation of protein degradation pathways. BJU Int. 2011 May;107(10):1676-84 Authors: Kanika ND, Chang J, Tong Y, Tiplitsky S, Lin J, Yohannes E, Tar M, Chance M, Christ GJ, Melman A, Davies KD What's known on the subject? and What does the study add? Diabetes is a common precursor for ladder pathology, including detrusor overactivity and cystopathy. There is preliminary, but increasing evidence, suggesting that oxidative stress plays a significant role in the development of diabetic complications including its affect on the bladder. In the present study we investigated the effect of streptozotocin induced-diabetes in rats on the global expression of genes in the rat bladder using microarray analysis, and combined this data with our previously reported study looking at changes in protein levels using proteomics. This analysis demonstrated that markers of oxidative stress were significantly increased in the diabetic bladder. Overall, our work adds to the growing body of evidence that diabetic cystopathy is associated with oxidative damage of smooth muscle cells, and results in protein damage and activation of apoptotic pathways which may contribute to a deterioration in bladder function. PMID: 21518418 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Fabrication of functional cardiac, skeletal, and smooth muscle pumps in vitro. Artif Organs. 2011 Jan;35(1):69-74 Authors: Evers R, Khait L, Birla RK Cardiovascular disease is one of the leading causes of death in the United States, and new treatments need to be developed in order to provide novel therapies. Tissue engineering aims to develop biologic substitutes that restore tissue function. The purpose of the current study was to construct cell-based pumps, which can be viewed as biologic left ventricular assist devices. The pumps were fabricated by culturing cardiac, skeletal, and smooth muscle cells within a fibrin gel and then each 3-D tissue construct was wrapped around a decellularized rodent aorta. We described the methodology for pump fabrication along with functional performance metric, determined by the intra-luminal pressure. In addition, histologic evaluation showed a concentric organization of components, with the muscle cells positioned on the outermost surface, followed by the fibrin gel and the decellularized aorta formed the innermost layer. Though early in development, cell-based muscle pumps have tremendous potential to be used for basic and applied research, and with further development, can be used clinically as cell-based left ventricular assist devices. PMID: 20618224 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Chitosan Scaffolds Containing Hyaluronic Acid for Cartilage Tissue Engineering. Tissue Eng Part C Methods. 2011 Apr 25; Authors: Correia CR, Moreira-Teixeira LS, Moroni L, Reis RL, Van Blitterswijk CA, Karperien M, Mano JF Scaffolds derived from natural polysaccharides are very promising in tissue engineering applications and regenerative medicine, as they resemble glycosaminoglycans in the extracellular matrix (ECM). In this study, we have prepared freeze-dried composite scaffolds of chitosan (CHT) and hyaluronic acid (HA) in different weight ratios containing either no HA (control) or 1%, 5%, or 10% of HA. We hypothesized that HA could enhance structural and biological properties of CHT scaffolds. To test this hypothesis, physicochemical and biological properties of CHT/HA scaffolds were evaluated. Scanning electron microscopy micrographs, mechanical properties, swelling tests, enzymatic degradation, and Fourier transform infrared (FTIR) chemical maps were performed. To test the ability of the CHT/HA scaffolds to support chondrocyte adhesion and proliferation, live-dead and MTT assays were performed. Results showed that CHT/HA composite scaffolds are noncytotoxic and promote cell adhesion. ECM formation was further evaluated with safranin-O and alcian blue staining methods, and glycosaminoglycan and DNA quantifications were performed. The incorporation of HA enhanced cartilage ECM production. CHT/5HA had a better pore network configuration and exhibited enhanced ECM cartilage formation. On the basis of our results, we believe that CHT/HA composite matrixes have potential use in cartilage repair. PMID: 21517692 [PubMed - as supplied by publisher] | | | | | | | | | |  | |  | |  |
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