title: Cartilaginous ECM component-modification of the micro-bead culture system for chondrogenic differentiation of mesenchymal stem cells.
abstract: In this study a 3-D alginate microbead platform was coated with cartilaginous extracellular matrix (ECM) components to emulate chondrogenic microenvironment in vivo for the differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). BMSCs were seeded onto the microbead surface and the effect of the modified microbead on BMSC adhesion, proliferation and chondrogenic differentiation was studied, and compared to chondrogenesis in conventional pellet culture. Our results indicated that microbead system promoted BMSC proliferation and protein deposition resulting in the formation of bigger aggregates compared to conventional pellet culture. Analysis of the aggregates indicated that chondroitin sulfate (CS)- and Col2-coated microbeads enhanced the chondrogenic differentiation of hBMSCs, with increasing formation of glycosaminoglycan (GAG) and collagen II deposition in histology, immunohistochemistry and real time PCR analysis. In addition, Col2-coated microbeads resulted in hypertrophic maturation of the differentiated chondrocytes, similar to conventional pellet culture, while CS-coated microbeads were able to retain the pre-hypertrophy state of the differentiated cells. Our result suggested that provision of suitable cartilaginous microenvironment in a 3-D system can promote the chondrogenic differentiation of BMSC and influence the phenotype of resulting chondrocytes. Our microbead system provides an easy method of processing a 3-D alginate system that allows the possibility of scaling up chondrogenic pellet production for clinical application, while the modifiable microbeads also provide an adjustable 3-D platform for the study of co-interaction of ECM and differentiation factors during the stem cell differentiation.
authors.affiliation: Department of Orthopaedic Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore NUS Tissue Engineering Program (NUSTEP), National University Hospital, Lower Kent Ridge Road, Singapore 119074, Republic of Singapore.
authors.forename: Ying-Nan
authors.initials: YN
authors.lastname: Wu
authors.forename: Zheng
authors.initials: Z
authors.lastname: Yang
authors.forename: James H P
authors.initials: JH
authors.lastname: Hui
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: Ouyang
authors.forename: Eng Hin
authors.initials: EH
authors.lastname: Lee
mesh_terms: D000464:Alginates / Q000737:chemistry; D000818:Animals; D002356:Cartilage / Q000378:metabolism*; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000502:physiology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D048271:Chitosan / Q000737:chemistry; D020219:Chondrogenesis / Q000502:physiology*; D024042:Collagen Type I / Q000378:metabolism; D024043:Collagen Type II / Q000378:metabolism; D024121:Collagen Type X / Q000378:metabolism; D005109:Extracellular Matrix / Q000737:chemistry*; D006025:Glycosaminoglycans / Q000378:metabolism; D006801:Humans; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000502:physiology*; D008863:Microspheres; D013499:Surface Properties
chemical_list: D000464:Alginates; D024042:Collagen Type I; D024043:Collagen Type II; D024121:Collagen Type X; D006025:Glycosaminoglycans; D048271:Chitosan