|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | | A Randomized, Double-Blind, Placebo-Controlled Trial of Anticholinergic Medication for Nonresponders to Desmopressin for Monosymptomatic Nocturnal Enuresis. Curr Urol Rep. 2010 Oct 23; Authors: Hodges SJ, Atala A PMID: 20972651 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Wharton's Jelly Mesenchymal Stem Cells as Candidates for Beta Cells Regeneration: Extending the Differentiative and Immunomodulatory Benefits of Adult Mesenchymal Stem Cells for the Treatment of Type 1 Diabetes. Stem Cell Rev. 2010 Oct 23; Authors: Anzalone R, Lo Iacono M, Loria T, Di Stefano A, Giannuzzi P, Farina F, La Rocca G Mesenchymal stem cells (MSC) are uniquely capable of crossing germinative layers borders (i.e. are able to differentiate towards ectoderm-, mesoderm- and endoderm-derived cytotypes) and are viewed as promising cells for regenerative medicine approaches in several diseases. Type I diabetes therapy should potentially benefit from such differentiated cells: the search for alternatives to organ/islet transplantation strategies via stem cells differentiation is an ongoing task, significant goals having been achieved in most experimental settings (e.g. insulin production and euglycaemia restoration), though caution is still needed to ensure safe and durable effects in vivo. MSC are obtainable in high numbers via ex vivo culture and can be differentiated towards insulin-producing cells (IPC). Moreover, recent reports evidenced that MSC possess immunomodulatory activities (acting on both innate and acquired immunity effectors) which should result in a reduction of the immunogenicity of transplanted cells, thus limiting rejection. Moreover it has been proposed that MSC administration should be used to attenuate the autoimmune processes which lead to the destruction of beta cells. This review illustrates the recent advances made in differentiating human MSC to IPC. In particular, we compare the effectiveness of the differentiation protocols applied, the markers and functional assays used to characterize differentiated progeny, and the in vivo controls. We further speculate on how MSC derived from Wharton's jelly of human umbilical cord may represent a more promising regenerative medicine tool, as recently demonstrated for endoderm-derived organs (as liver) in human subjects, also considering their peculiar immunomodulatory features compared to other MSC populations. PMID: 20972649 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Development of a Bioengineered Skin-Humanized Mouse Model for Psoriasis. Dissecting Epidermal-Lymphocyte Interacting Pathways. Am J Pathol. 2010 Oct 22; Authors: Guerrero-Aspizua S, García M, Murillas R, Retamosa L, Illera N, Duarte B, Holguín A, Puig S, Hernández MI, Meana A, Jorcano JL, Larcher F, Carretero M, Del Río M Over the past few years, whole skin xenotransplantation models that mimic different aspects of psoriasis have become available. However, these models are strongly constrained by the lack of skin donor availability and homogeneity. We present in this study a bioengineering-based skin-humanized mouse model for psoriasis, either in an autologous version using samples derived from psoriatic patients or, more importantly, in an allogeneic context, starting from skin biopsies and blood samples from unrelated healthy donors. After engraftment, the regenerated human skin presents the typical architecture of normal human skin but, in both cases, immunological reconstitution through intradermal injection in the regenerated skin using in vitro-differentiated T1 subpopulations as well as recombinant IL-17 and IL-22 Th17 cytokines, together with removal of the stratum corneum barrier by a mild abrasive treatment, leads to the rapid conversion of the skin into a bona fide psoriatic phenotype. Major hallmarks of psoriasis were confirmed by the evaluation of specific epidermal differentiation and proliferation markers as well as the mesenchymal milieu, including angiogenesis and infiltrate. Our bioengineered skin-based system represents a robust platform to reliably assess the molecular and cellular mechanisms underlying the complex interdependence between epidermal cells and the immune system. The system may also prove suitable to assess preclinical studies that test the efficacy of novel therapeutic treatments and to predict individual patient response to therapy. PMID: 20971736 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Structured coculture of stem cells and disc cells prevent disc degeneration in a rat model. Spine J. 2010 Oct 23; Authors: Allon AA, Aurouer N, Yoo BB, Liebenberg EC, Buser Z, Lotz JC BACKGROUND CONTEXT: Harnessing the potential of stem cells is an important strategy for regenerative medicine. This study explores the use of bilaminar coculture pellets (BCPs) of mesenchymal stem cells (MSCs) and nucleus pulposus cells (NPCs) as a cell-based therapy for intervertebral disc regeneration. Prior in vitro experiments have shown that BCP can help differentiate MSCs and substantially improve new matrix deposition. PURPOSE: To evaluate the clinical relevance of BCPs by testing the system in vivo. STUDY DESIGN/SETTING: We have designed a novel spherical BCP where MSCs are enclosed in a shell of NPCs. The pellets were tested in vivo in a rat tail model of disc degeneration. METHODS: Rat caudal intervertebral discs were denucleated and treated with BCP in a fibrin sealant (FS) carrier (controls were MSCs suspended in FS; NPCs suspended in FS; MSCs and NPCs suspended in FS; FS only; and surgery only). At 14 and 35 days after implantation, the animals were euthanized and discs were evaluated for proteoglycan content, enzyme-linked immunosorbent assay for inflammatory cytokines, cell retention using polymerase chain reaction, disc height, histology, and disc grade based on a blinded scoring system. RESULTS: The proteoglycan and cytokine levels were not significantly different among groups. The BCP group had higher cell retention than controls. Disc height and disc grade increased over time only in the BCP group. Bilaminar coculture pellets were the only treatment to show proteoglycan staining in the nucleus space at 35 days. CONCLUSIONS: This study shows that BCPs may prevent postnucleotomy disc degeneration in vivo. Larger animals and longer time points will be necessary to further judge potential clinical impact. As opposed to strategies that require growth factor supplements, predifferentiation, or genetic manipulations, BCPs are a self-sustaining and targeted method for tissue regeneration in situ. PMID: 20971687 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Exogenous nucleosides modulate expression and activity of transcription factors in Caco-2 cells. J Nutr Biochem. 2010 Oct 20; Authors: Ortega A, Gil A, Sánchez-Pozo A Dietary nucleotides (NTs) have an important role in cellular and humoral immunity, intestinal growth, differentiation and recovery from tissue damage. Nucleosides (NSs) are the best-absorbed chemical form of NTs in the intestinal epithelium. The aim of this study was to evaluate the effects of NSs on the activity and expression of multiple transcription factors (TFs) in Caco-2 cells, as a possible molecular mechanism by which NSs modulate gene expression in human intestinal cells. The effects of NS-supplemented media on human Caco-2 cell proliferation, viability, protein and RNA concentration were determined, and the activity and expression profiles of multiple TFs were analyzed by using an array-based technology. Exogenous NSs did not affect Caco-2 cell proliferation or viability but increased the protein content in cytoplasm and nucleus and the nuclear protein/RNA ratio. The addition of NSs to the media increased the expression and activity of the TFs CCAAT displacement protein (CUX1), v-ets avian erythroblastosis virus E26 oncogene homolog 1 (ETS1) and SMAD family member 2. In contrast, NS addition decreased the expression and activity of the general upstream stimulatory factor 1 (USF1), glucocorticoid receptor (NR3C1), NFKB and tumor protein p53. In conclusion, our results suggest that exogenous NSs affect the expression and activity of several TFs involved in cell growth, differentiation, apoptosis, immune response and inflammation. PMID: 20970311 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Age-related changes in mesenchymal stem cells derived from rhesus macaque bone marrow. Aging Cell. 2010 Oct 22; Authors: Yu JM, Wu X, Gimble JM, Guan X, Freitas MA, Bunnell BA The regeneration potential of mesenchymal stem cells (MSCs) diminishes with advanced age and this diminished potential is associated with changes in cellular functions. This study compared MSCs isolated from the bone marrow of rhesus monkeys (rBMSCs) in three age groups: young (<5 years), middle (8-10 years), and old (>12 years). The effects of aging on stem cell properties and indicators of stem cell fitness such as proliferation, differentiation, circadian rhythms, stress response proteins, miRNA expression, and global histone modifications in rBMSCs were analyzed. rBMSCs demonstrated decreased capacities for proliferation and differentiation as a function of age. The production of heat shock protein 70 (HSP70) and heat shock factor 1 (HSF1) were also reduced with increasing age. The level of a core circadian protein, Rev-erb α, was significantly increased in rBMSCs from old animals. Furthermore, analysis of miRNA expression profiles revealed an up-regulation of mir-766 and mir-558 and a down-regulation of mir-let-7f, mir-125b, mir-222, mir-199-3p, mir-23a, and mir-221 in old rBMSCs compare to young rBMSCs. However, there were no significant age related changes in the global histone modification profiles of the 4 histone core proteins: H2A, H2B, H3, and H4 on rBMSCs. These changes represent novel insights into the aging process and could have implications regarding the potential for autologous stem cells therapy in older patients. PMID: 20969724 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | [Nuclear heterogeneity and proliferative capacity of human adipose derived MSC-like cells]. Tsitologiia. 2010;52(8):616-20 Authors: Adipose derived stem cells (ADSCs) are MSC-like cells which could be easily used for regenerative medicine. Here, the morphology and proliferative capacity of human ADSCs is discribed. ADSCs were analyzed after one month of cultivation at a density of 10 cells/cm2. 21 colonies were counted. Few atypical cells (huge nuclei and cytoplasm) were found in 9 out of 17 colonies analyzed. ANOVA demonstrated that colonies also differed (P = 0.0025) in nuclei dimensions and scatter in the dimensions in each colony. Nuclei dimensions and cell density logarithms correlated in reverse proportion (-0.7; P = 0.002). Thus, ADSCs were heterogeneous and represented two types of cells: small highly proliferative and large low proliferative cells. Cell heterogeneity observed in some colonies might be due to cells registered at different cell cycle phases. Stable and typical morphology, colony-formation capability and high proliferative capacity of cells indicate visceral adipose tissue as a rich source of ADSCs. PMID: 20968094 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Origins of gliogenic stem cell populations within adult skin and bone marrow. Stem Cells Dev. 2010 Jul;19(7):1055-65 Authors: Hunt DP, Sajic M, Phillips H, Henderson D, Compston A, Smith K, Chandran S The generation of Schwann cells from precursors within adult skin and bone marrow is of significant clinical interest because of the opportunities for disease modelling and strategies for remyelination. Recent evidence has suggested that glial cells can be generated from (i) mesenchymal stem cells (MSCs) within adult bone marrow and (ii) skin-derived precursor cells (SKPs) within adult skin. However, there is a need to clarify the developmental mechanism whereby such multipotent adult stem cell populations generate glia. We used Wnt1-Cre/Rosa26R(LacZ) and Wnt1-Cre/Rosa26R(YFP) neural crest reporter mice to test the hypothesis that (i) MSCs and (ii) SKPs represent adult gliogenic precursor cells of neural crest origin. We demonstrate that, although labeled cells can be identified within long bone preparation, such cells are rarely found in marrow plugs. Moreover, we did not find evidence of a neural crest origin of bone marrow-derived MSCs and were not able to provide a developmental rationale for the derivation of glial cells from MSCs using this approach. In contrast, we provide robust evidence for the neural crest origin of SKPs derived from adult skin. These precursor cells reliably generate cells with a Schwann cell phenotype, expressing appropriate transcription factors and Schwann cell markers. We demonstrate multiple anatomical origins of gliogenic SKPs within adult skin. We conclude that SKPs, rather than bone marrow-derived MSCs, represent a more defined and developmentally rational source for the study and generation of Schwann cells from readily accessible adult tissues. PMID: 20102260 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Proteomic characterization of the conditioned media produced by the visceral endoderm-like cell lines HepG2 and END2: toward a defined medium for the osteogenic/chondrogenic differentiation of embryonic stem cells. Stem Cells Dev. 2009 Jan-Feb;18(1):77-91 Authors: Kang Y, Nagy JM, Polak JM, Mantalaris A Visceral endoderm (VE) is an extraembryonic cell layer formed before gastrulation that secretes critical factors involved in embryonic development with inductive effects on embryonic stem cell (ESC) differentiation. We utilized the conditioned media (CM) from the VE-like cell lines, HepG2 and END2, to enhance lineage-specific differentiation of murine ESCs (mESCs) toward the osteogenic lineage. Previously, we have demonstrated that use of the HepG2-CM resulted in the efficient osteogenic/chondrogenic differentiation of mESCs without embryoid body (EB) formation. In this study, we demonstrate, for the first time, the osteogenic-inducing activity of END2-CM, suggesting a potential shared protein profile between HepG2- and END2-CM. To identify the active factors in the CM, proteomic analysis using differential gel electrophoresis coupled with matrix-assisted laser desorption/ionization was performed on the two CM, resulting in six proteins being established to be present in both CM, including ones that may function on the epithelial-mesenchymal transition (EMT). Our results represent the first study on the VE-like cell line secretome and provide information on VE proteins identifying possible candidate proteins to be used for mesoderm-specific osteogenic differentiation. PMID: 18393639 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | A novel MSC-seeded triphasic construct for the repair of osteochondral defects. J Orthop Res. 2010 Dec;28(12):1586-99 Authors: Marquass B, Somerson JS, Hepp P, Aigner T, Schwan S, Bader A, Josten C, Zscharnack M, Schulz RM Mesenchymal stem cells (MSC) are increasingly replacing chondrocytes in tissue engineering based research for treatment of osteochondral defects. The aim of this work was to determine whether repair of critical-size chronic osteochondral defects in an ovine model using MSC-seeded triphasic constructs would show results comparable to osteochondral autografting (OATS). Triphasic implants were engineered using a beta-tricalcium phosphate osseous phase, an intermediate activated plasma phase, and a collagen I hydrogel chondral phase. Autologous MSCs were used to seed the implants, with chondrogenic predifferentiation of the cells used in the cartilage phase. Osteochondral defects of 4.0 mm diameter were created bilaterally in ovine knees (n = 10). Six weeks later, half of the lesions were treated with OATS and half with triphasic constructs. The knees were dissected at 6 or 12 months. With the chosen study design we were not able to demonstrate significant differences between the histological scores of both groups. Subcategory analysis of O'Driscoll scores showed superior cartilage bonding in the 6-month triphasic group compared to the autograft group. The 12-month autograft group showed superior cartilage matrix morphology compared to the 12-month triphasic group. Macroscopic and biomechanical analysis showed no significant differences at 12 months. Autologous MSC-seeded triphasic implants showed comparable repair quality to osteochondral autografts in terms of histology and biomechanical testing. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1586-1599, 2010. PMID: 20973061 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Evaluating osteochondral defect repair potential of autologous rabbit bone marrow cells on type II collagen scaffold. Cytotechnology. 2010 Oct 23; Authors: Chen WC, Yao CL, Wei YH, Chu IM The feasibility of using genipin cross-linked type II collagen scaffold with rabbit bone marrow mesenchymal stem cells (RBMSCs) to repair cartilage defect was herein studied. Induction of RBMSCs into chondrocytic phenotype on type II collagen scaffold in vitro was conducted using TGF-β 3 containing medium. After 3-weeks of induction, chondrocytic behavior, including marker genes expression and specific extracellular matrix (ECM) secretion, was observed. In the in vivo evaluation experiment, the scaffolds containing RBMSCs without prior induction were autologous implanted into the articular cartilage defects made by subchondral drilling. The repairing ability was evaluated. After 2 months, chondrocyte-like cells with lacuna structure and corresponding ECM were found in the repaired sites without apparent inflammation. After 24 weeks, we could easily find cartilage structure the same with normal cartilage in the repair site. In conclusion, it was shown that the scaffolds in combination of in vivo conditions can induce RBMSCs into chondrocytes in repaired area and would be a possible method for articular cartilage repair in clinic and cartilage tissue engineering. PMID: 20972620 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Development of a Bioengineered Skin-Humanized Mouse Model for Psoriasis. Dissecting Epidermal-Lymphocyte Interacting Pathways. Am J Pathol. 2010 Oct 22; Authors: Guerrero-Aspizua S, García M, Murillas R, Retamosa L, Illera N, Duarte B, Holguín A, Puig S, Hernández MI, Meana A, Jorcano JL, Larcher F, Carretero M, Del Río M Over the past few years, whole skin xenotransplantation models that mimic different aspects of psoriasis have become available. However, these models are strongly constrained by the lack of skin donor availability and homogeneity. We present in this study a bioengineering-based skin-humanized mouse model for psoriasis, either in an autologous version using samples derived from psoriatic patients or, more importantly, in an allogeneic context, starting from skin biopsies and blood samples from unrelated healthy donors. After engraftment, the regenerated human skin presents the typical architecture of normal human skin but, in both cases, immunological reconstitution through intradermal injection in the regenerated skin using in vitro-differentiated T1 subpopulations as well as recombinant IL-17 and IL-22 Th17 cytokines, together with removal of the stratum corneum barrier by a mild abrasive treatment, leads to the rapid conversion of the skin into a bona fide psoriatic phenotype. Major hallmarks of psoriasis were confirmed by the evaluation of specific epidermal differentiation and proliferation markers as well as the mesenchymal milieu, including angiogenesis and infiltrate. Our bioengineered skin-based system represents a robust platform to reliably assess the molecular and cellular mechanisms underlying the complex interdependence between epidermal cells and the immune system. The system may also prove suitable to assess preclinical studies that test the efficacy of novel therapeutic treatments and to predict individual patient response to therapy. PMID: 20971736 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A robust high-throughput sandwich cell-based drug screening platform. Biomaterials. 2010 Oct 22; Authors: Zhang S, Tong W, Zheng B, Susanto TA, Xia L, Zhang C, Ananthanarayanan A, Tuo X, Sakban RB, Jia R, Iliescu C, Chai KH, McMillian M, Shen S, Leo H, Yu H Hepatotoxicity evaluation of pharmaceutical lead compounds in early stages of drug development has drawn increasing attention. Sandwiched hepatocytes exhibiting stable functions in culture represent a standard model for hepatotoxicity testing of drugs. We have developed a robust and high-throughput hepatotoxicity testing platform based on the sandwiched hepatocytes for drug screening. The platform involves a galactosylated microfabricated membrane sandwich to support cellular function through uniform and efficient mass transfer while protecting cells from excessive shear. Perfusion bioreactor further enhances mass transfer and cellular functions over long period; and hepatoctyes are readily transferred to 96-well plate for high-throughput robotic liquid handling. The bioreactor design and perfusion flow rate are optimized by computational fluid dynamics simulation and experimentally. The cultured hepatocytes preserved 3D cell morphology, urea production and cytochrome p450 activity of the mature hepatocytes for 14 days. When the perfusion-cultured sandwich is transferred to 96-well plate for drug testing, the hepatocytes exhibited improved drug sensitivity and low variability in hepatotoxicity responses amongst cells transferred from different dates of perfusion culture. The platform enables robust high-throughput screening of drug candidates. PMID: 20971505 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Effects of Bioactive Glass Nanoparticles on Mechanical and Biological Behavior of Composite Coated Scaffolds. Acta Biomater. 2010 Oct 21; Authors: Roohani-Esfahani SI, Nouri-Khorasani S, Lu ZF, Appleyard RC, Zreiqat H Biphasic calcium phosphates (BCP) scaffolds are widely used for bone tissue regeneration. However, brittleness, low mechanical properties and compromised bioactivities, at present, are their major disadvantages. In this study, we coated a nanocomposite layer consisting of bioactive glass nanoparticles (nBG) and polycaprolactone (PCL) over the struts of a BCP scaffold (BCP/PCL-nBG) to enhance its mechanical and biological behavior. The effect of various nBG concentrations (1 to 90 wt%) on the mechanical properties and in-vitro behavior of the scaffolds was comprehensively examined and compared with that for BCP scaffold coated with PCL and HA nanoparticles (nHA) (BCP/PCL-nHA) and BCP scaffold coated with just PCL layer (BCP/PCL). By the introduction of 1 to 90 wt% nBG, scaffolds showed a compressive strength in the range of 0.2-1.45 MPa and a modulus of 19.3 to 49.4 MPa. This trend was also observed for BCP/PCL-nHA scaffolds however nBG induced even better bioactivity and faster degradation rate. The maximum compressive strength (increased ∼14 times) and modulus (increased ∼3 times) were achieved when 30 wt% nBG was added, compared to BCP scaffolds. Moreover, BCP/PCL-nBG scaffolds induced the differentiation of primary human bone derived cells (HOBs), with significant upregulation of osteogenic gene expression for Runx2, osteopontin and bone sialoprotein, compared to the other groups. PMID: 20971219 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Nanofibrous architecture of silk fibroin scaffolds prepared with a mild self-assembly process. Biomaterials. 2010 Oct 20; Authors: Lu Q, Wang X, Lu S, Li M, Kaplan DL, Zhu H Besides excellent biocompatibility and biodegradability, a useful tissue engineering scaffold should provide suitable macropores and nanofibrous structure, similar to extracellular matrix (ECM), to induce desired cellular activities and to guide tissue regeneration. In the present study, a mild process to prepare porous and nanofibrous silk-based scaffolds from aqueous solution is described. Using collagen to control the self-assembly of silk, nanofibrous silk scaffolds were firstly achieved through lyophilization. Water annealing was used to generate insolubility in the silk-based scaffolds, thereby avoiding the use of organic solvents. The nano-fibrils formed in the silk-collagen scaffolds had diameters of 20-100 nm, similar with native collagen in ECM. The silk-collagen scaffolds dissolved slowly in PBS solution, with about a 28% mass lost after 4 weeks. Following the dissolution or degradation, the nanofibrous structure inside the macropore walls emerged and interacted with cells directly. During in vitro cell culture, the nanofibrous silk-collagen scaffolds containing 7.4% collagen demonstrated significantly improved cell compatibility when compared with salt-leached silk scaffolds and silk-collagen scaffolds containing 20% collagen that emerged less nano-fibrils. Therefore, this new process provides useful scaffolds for tissue engineering applications. Furthermore, the process involves all-aqueous, room temperature and pressure processing without the use of toxic chemicals or solvents, offering new green chemistry approaches, as well as options to load bioactive drugs or growth factors into process. PMID: 20970185 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Tissue engineering and stem cells: Basic principles and applications in urology. Int J Urol. 2010 Oct 24; Authors: Shokeir AA, Harraz AM, El-Din AB To overcome problems of damaged urinary tract tissues and complications of current procedures, tissue engineering (TE) techniques and stem cell (SC) research have achieved great progress. Although diversity of techniques is used, urologists should know the basics. We carried out a literature review regarding the basic principles and applications of TE and SC technologies in the genitourinary tract. We carried out MEDLINE/PubMed searches for English articles until March 2010 using a combination of the following keywords: bladder, erectile dysfunction, kidney, prostate, Peyronie's disease, stem cells, stress urinary incontinence, testis, tissue engineering, ureter, urethra and urinary tract. Retrieved abstracts were checked, and full versions of relevant articles were obtained. Scientists have achieved great advances in basic science research. This is obvious by the tremendous increase in the number of publications. We divided this review in two topics; the first discusses basic science principles of TE and SC, whereas the second part delineates current clinical applications and advances in urological literature. TE and SC applications represent an alternative resource for treating complicated urological diseases. Despite the paucity of clinical trials, the promising results of animal models and continuous work represents the hope of treating various urological disorders with this technology. PMID: 20969644 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | The enhancement of bone allograft incorporation by the local delivery of the sphingosine 1-phosphate receptor targeted drug FTY720. Biomaterials. 2010 Sep;31(25):6417-24 Authors: Petrie Aronin CE, Shin SJ, Naden KB, Rios PD, Sefcik LS, Zawodny SR, Bagayoko ND, Cui Q, Khan Y, Botchwey EA Poor vascularization coupled with mechanical instability is the leading cause of post-operative complications and poor functional prognosis of massive bone allografts. To address this limitation, we designed a novel continuous polymer coating system to provide sustained localized delivery of pharmacological agent, FTY720, a selective agonist for sphingosine 1-phosphate receptors, within massive tibial defects. In vitro drug release studies validated 64% loading efficiency with complete release of compound following 14 days. Mechanical evaluation following six weeks of healing suggested significant enhancement of mechanical stability in FTY720 treatment groups compared with unloaded controls. Furthermore, superior osseous integration across the host-graft interface, significant enhancement in smooth muscle cell investment, and reduction in leukocyte recruitment was evident in FTY720 treated groups compared with untreated groups. Using this approach, we can capitalize on the existing mechanical and biomaterial properties of devitalized bone, add a controllable delivery system while maintaining overall porous structure, and deliver a small molecule compound to constitutively target vascular remodeling, osseous remodeling, and minimize fibrous encapsulation within the allograft-host bone interface. Such results support continued evaluation of drug-eluting allografts as a viable strategy to improve functional outcome and long-term success of massive cortical allograft implants. PMID: 20621764 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | The role of pharmacologically active microcarriers releasing TGF-beta3 in cartilage formation in vivo by mesenchymal stem cells. Biomaterials. 2010 Sep;31(25):6485-93 Authors: Bouffi C, Thomas O, Bony C, Giteau A, Venier-Julienne MC, Jorgensen C, Montero-Menei C, Noël D Cartilage engineering using mesenchymal stem cells (MSC) will require the use of a scaffold which will act as a support for cell adhesion keeping the cells in the cartilage defect. Optimally, a tissue engineered construct should allow sustained delivery of bioactive factors capable of inducing MSC differentiation into chondrocytes and should be easily injected inside the cartilage lesions to avoid surgical operations. We therefore developed pharmacologically active microcarriers (PAM) made of poly-lactic-co-glycolic acid (PLGA) produced using an oil-in-water (o/w) emulsion method. The microspheres were coated with a biomimetic surface of fibronectin (FN) and engineered to release TGF-beta3 as a chondrogenic differentiation factor. When human MSCs were incubated in vitro with TGF-beta3 releasing FN-coated PAMs in chondrogenic medium, they firmly adhered onto the surface of PAMs rapidly forming cell aggregates. After 3 weeks, strong up-regulation of cartilage-specific markers was observed both at the mRNA and protein level whereas osteogenic or adipogenic genes could not be detected. Importantly, implantation of MSC/TGF-beta3 releasing PAM complexes in SCID mice resulted in the formation of histologically resembling cartilage which stained positive for chondrocyte markers, collagen II and aggrecan. The present study demonstrated that functionalized PLGA-based microparticles can provide an appropriate environment for chondrogenic differentiation of MSCs and should contribute to injectable biomedical device development improving in vivo cartilage engineering. PMID: 20570347 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Mesenchymal stem cells: engineering regeneration. Clin Transl Sci. 2008 May;1(1):34-5 Authors: Behfar A, Terzic A PMID: 20443816 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Proteomic characterization of the conditioned media produced by the visceral endoderm-like cell lines HepG2 and END2: toward a defined medium for the osteogenic/chondrogenic differentiation of embryonic stem cells. Stem Cells Dev. 2009 Jan-Feb;18(1):77-91 Authors: Kang Y, Nagy JM, Polak JM, Mantalaris A Visceral endoderm (VE) is an extraembryonic cell layer formed before gastrulation that secretes critical factors involved in embryonic development with inductive effects on embryonic stem cell (ESC) differentiation. We utilized the conditioned media (CM) from the VE-like cell lines, HepG2 and END2, to enhance lineage-specific differentiation of murine ESCs (mESCs) toward the osteogenic lineage. Previously, we have demonstrated that use of the HepG2-CM resulted in the efficient osteogenic/chondrogenic differentiation of mESCs without embryoid body (EB) formation. In this study, we demonstrate, for the first time, the osteogenic-inducing activity of END2-CM, suggesting a potential shared protein profile between HepG2- and END2-CM. To identify the active factors in the CM, proteomic analysis using differential gel electrophoresis coupled with matrix-assisted laser desorption/ionization was performed on the two CM, resulting in six proteins being established to be present in both CM, including ones that may function on the epithelial-mesenchymal transition (EMT). Our results represent the first study on the VE-like cell line secretome and provide information on VE proteins identifying possible candidate proteins to be used for mesoderm-specific osteogenic differentiation. PMID: 18393639 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Histopathological analysis of human specimens removed from the injection area of expanded adipose-derived stem cells. Histopathology. 2010 Jun;56(7):979-82 Authors: García-Arranz M, Gómez-Pinedo U, Hardisson D, Herreros D, Guadalajara H, García-Gómez I, García-Verdugo JM, García-Olmo D PMID: 20636801 [PubMed - indexed for MEDLINE] | | | | | | | | | |  | |  | |  |
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