title: Probing cell-matrix interactions in RGD-decorated macroporous poly (ethylene glycol) hydrogels for 3D chondrocyte culture.
abstract: Macroporous hydrogels have shown great promise as scaffolds for cartilage engineering by facilitating nutrition transport and tissue in growth. Cell-matrix adhesion-a fundamental process in tissue engineering-has shown a profound effect on subsequent cell phenotype, extracellular matrix (ECM) accumulation, and tissue reorganization. In this study, arginine-glycine-aspartic acid (RGD) was introduced to macroporous hydrogels of poly (ethylene glycol) (PEG) to fabricate PEG-G400 (with 0.4mM RGD) and PEG-G2000 (2mM RGD) to probe the cell-matrix interactions within hydrogels. Primary chondrocytes demonstrated a slightly stretched morphology with increasing RGD concentration and PEG-G2000 hydrogels boosted cell viability, proliferation, and deposition of collagen II and GAG, in comparison to the PEG-G400 and PEG-RED groups. Results also revealed chondrocytes within the cell aggregates underwent dedifferentiation and hypertrophy within RGD incorporated hydrogels, as evidenced by the high level of gene expression of collagen I on day 14 and strong immunohistological staining of collagen X and collagen I on day 35. Evidently, a high concentration of RGD (2mM RGD) enhanced cell-matrix interactions through elevating the expression of integrin β1 and vinculin. Thus, the integration of RGD in macroporous hydrogels with a concentration of 2 mM may be sufficient for improving cell functionality, with a slight probability of dedifferentiation and hypertrophy of chondrocytes.
authors.affiliation: Department of Biomedical Engineering, College of Engineering, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Zhang
authors.forename: Ayeesha
authors.initials: A
authors.lastname: Mujeeb
authors.forename: Yanan
authors.initials: Y
authors.lastname: Du
authors.forename: Jianhao
authors.initials: J
authors.lastname: Lin
authors.forename: Zigang
authors.initials: Z
authors.lastname: Ge
mesh_terms: D053674:Aggrecans / Q000235:genetics; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D002448:Cell Adhesion; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D003094:Collagen / Q000235:genetics; D005109:Extracellular Matrix / Q000378:metabolism; D015870:Gene Expression; D006025:Glycosaminoglycans / Q000378:metabolism; D020100:Hydrogels; D007150:Immunohistochemistry; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D009842:Oligopeptides / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry*; D016062:Porosity; D055758:SOX9 Transcription Factor / Q000235:genetics; D034421:Sus scrofa; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D053674:Aggrecans; D001672:Biocompatible Materials; D006025:Glycosaminoglycans; D020100:Hydrogels; D009842:Oligopeptides; D055758:SOX9 Transcription Factor; D011092:Polyethylene Glycols; C047981:arginyl-glycyl-aspartic acid; D003094:Collagen