title: Injectable Biodegradable Poly(ethylene glycol)/RGD Peptide Hybrid Hydrogels for in vitro Chondrogenesis of Human Mesenchymal Stem Cells.
abstract: In this study, an injectable and biodegradable poly(ethylene glycol) (PEG)/arginine-glycine-aspartic (RGD) peptide hybrid hydrogel has been synthesized and used as a biomimetic scaffold for encapsulation of human mesenchymal stem cells (hMSCs). Tetrahydroxyl PEG was functionalized with acrylate, and then reacted with thiol-containing peptide (RGD). Gelation occurred within 30 min with the addition of cells and PEG-dithiol via Michael addition. The hydrogels synthesized with a peptide concentration of 1.0-5.0 mM achieved significantly greater cell viability when compared to the hydrogels without the RGD peptide. However, the effect of RGD on chondrogenesis was found to be dose-dependent. Immunohistology studies demonstrated that hMSCs encapsulated in the hydrogel matrix with 1.0 mM RGD and TGF-β3 showed enhanced positive staining for aggrecan and type II collagen as compared to that with 5.0 mM RGD and unmodified PEG hydrogels. RT-PCR results further revealed that the cells in hydrogels with 1 mM RGD expressed significantly higher levels of type II collagen than those in PEG hydogels without RGD peptide. These findings have demonstrated that the PEG-RGD hydrogels can be a promising scaffold to deliver hMSCs for cartilage repair.
authors: Department of Pharmacy, National University of Singapore, 18 Science Drive 4, Singapore 117543.
authors: Shao Qiong
authors: SQ
authors: Liu
authors: Quan
authors: Q
authors: Tian
authors: Lei
authors: L
authors: Wang
authors: James L
authors: JL
authors: Hedrick
authors: James Hoi Po
authors: JH
authors: Hui
authors: Yi Yan
authors: YY
authors: Yang
authors: Pui Lai Rachel
authors: PL
authors: Ee