Chondrogenic differentiation of human induced pluripotent stem cells in a photoclickable biomimetic PEG hydrogel

Event Abstract Back to Event Chondrogenic differentiation of human induced pluripotent stem cells in a photoclickable biomimetic PEG hydrogel Elizabeth Aisenbrey1*, Karin Payne2, Ganna Bilousova2 and Stephanie J. Bryant1* 1 University of Colorado, Chemical and Biological Engineering, United States 2 University of Colorado, Anschutz Medical Campus, United States Introduction: Cartilage lacks the ability to regenerate on its own, resulting in the necessity for alternative treatments such as tissue engineering[1]. The overall goal of this study was to develop a tissue engineering strategy for patient-specific repair of cartilage. Induced pluripotent stem cells (iPSCs) are an attractive cell source for cartilage tissue engineering because they can be obtained from a patient in a less invasive way than autologous chondrocytes or bone marrow derived MSCs, and unlike hMSCs, iPSCs have unlimited proliferation potential and the ability to differentiate into any cell in the body[2],[3]. In this study, human iPSCs were encapsulated into a photoclickable cartilage-like biomimetic poly(ethylene glycol) (PEG) hydrogel functionalized with chondroitin sulfate (ChS) and the cell adhesion peptide, RGD. Chondrogenesis was assessed in the cell-laden hydrogels and as a function of two growth factors TGFβ3 alone, BMP2 alone, or together. Materials and Methods: Human skin fibroblasts from a 50 year old female (ATCC) were reprogrammed under low oxygen (5%) conditions via mRNA transfection to generate iPSCs. These iPSCs were induced to become mesenchymal progenitors (iPSC-MPs) and were encapsulated in a hydrogel (9wt% 8-arm PEG(10kDa)norbornene, 1wt% thiolated ChS (16% conjugated), 1.4wt% PEG(1kDa)dithiol, and 0.1mM CYRGDS) via photopolymerization (7 minutes, 352 nm, 5 mW/cm2). The cell-laden hydrogels were cultured for 21 days in chondrogenic differentiation media without and with growth factors (+TGFB3 (2.5ng/ml), +BMP2 (25ng/ml), +TGFB3 (2.5 ng/ml) +BMP2 (25 ng/ml)). The iPSC-MPs were cultured as pellets in identical conditions or with media containing higher concentrations of growth factors ((+TGFB3 (10ng/ml), +BMP2 (100ng/ml), +TGFB3 (10ng/ml) +BMP2 (100ng/ml)). Differentiation was determined by qRT-PCR and immunohistochemistry for chondrogenic specific markers, sox-9, aggrecan, and collagen II and the hypertrophic marker collagen X. Results: After 21 days of culture, the expression of the chondrogenic markers sox9, aggrecan and collagen II were upregulated in the presence of TGFB3 and/or BMP2 compared to the constructs cultured without growth factors. Protein deposition of collagen II and aggrecan were found in all constructs cultured with TGFB3 and/or BMP2, although gene expression shows higher collagen II in constructs only cultured with BMP2. The relative gene expression of the hypertrophic marker collagen X was lower in the hydrogels cultured in BMP2 compared to those cultured in the presence of TGFB3, however, protein deposition was present. Similar results were obtained with the pellet culture when higher concentrations of growth factors were used. Chondrogenesis was not observed at the growth factor concentrations used with the hydrogel. Discussion and Conclusion: This study investigated if iPSCs, a novel cell source for articular cartilage tissue engineering, undergo chondrogenesis when cultured in a cartilage biomimetic hydrogel. The results from this study suggest that the presence of TGFB3 and/or BMP2 enhances chondrogenesis of iPSCs. Interestingly, lower concentrations of growth factors were needed for iPSCs to undergo chondrogenesis when in the hydrogel constructs compared to the pellet culture, suggesting that the biomimetic hydrogel is a promising scaffold for cartilage engineering. Studies are underway to investigate the effect of dynamic compression at physiological conditions on iPSCs. NSF Graduate Research Fellowship; NSF Career Award Grant # 0847390; Academic Enrichment Fund of the University of Colorado School of MedicineReferences:[1] Hunziker, E.B. Articular cartilage repair: Basic science and clinical progress. A review of the current status and prospects. Osteoarthritis Cartilage, 2002. 10(6): p. 432-63.[2] Takahashi, K., K. Tanabe, M. Ohnuki, M. Narita, T. Ichisaka, K. Tomoda, and S. Yamanaka. Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell, 2007. 131(5): p. 861-72.[3] Takahashi, K. and S. yamanaka. Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors. Cell, 2006. 126(4): p. 663-76. Keywords: Cell Differentiation, Hydrogel, Tissue Engineering, Biomimetic Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: Poster Topic: Biomimetic materials Citation: Aisenbrey E, Payne K, Bilousova G and Bryant SJ (2016). Chondrogenic differentiation of human induced pluripotent stem cells in a photoclickable biomimetic PEG hydrogel. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.02149 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Mar 2016; Published Online: 30 Mar 2016. * Correspondence: Dr. Elizabeth Aisenbrey, University of Colorado, Chemical and Biological Engineering, Boulder, CO, United States, Email1 Dr. Stephanie J Bryant, University of Colorado, Chemical and Biological Engineering, Boulder, CO, United States, stephanie.bryant@colorado.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Elizabeth Aisenbrey Karin Payne Ganna Bilousova Stephanie J Bryant Google Elizabeth Aisenbrey Karin Payne Ganna Bilousova Stephanie J Bryant Google Scholar Elizabeth Aisenbrey Karin Payne Ganna Bilousova Stephanie J Bryant PubMed Elizabeth Aisenbrey Karin Payne Ganna Bilousova Stephanie J Bryant Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.