Recent Research on Chondrocyte Dedifferentiation and Insights for Regenerative Medicine.

Chondrocytes maintain the balance of the extracellular matrix by synthesizing glycoproteins, collagen, proteoglycans and hyaluronic acid. Chondrocyte dedifferentiation refers to a process in which chondrocytes lose their mature differentiated phenotype and transform into a fibroblast-like morphology with fewer differentiated stages and inferior function under external stimulation. The important mechanism of homeostasis loss in osteoarthritis (OA) is a change in the chondrocyte phenotype.

Redifferentiation of genetically modified dedifferentiated chondrocytes in a microcavitary hydrogel.

Objectives: We genetically modified dedifferentiated chondrocytes (DCs) using lentiviral vectors and adenoviral vectors encoding TGF-β3 (referred to as transgenic groups below) and encapsulated these DCs in the microcavitary hydrogel and investigated the combinational effect on redifferentiation of the genetically manipulated DCs.

Results: The Cell Counting Kit-8 data indicated that both transgenic groups exhibited significantly higher cell viability in the first week but inferior cell viability in the subsequent timepoints compared with those of the control group. Real-time polymerase chain reaction and western blot analysis results demonstrated that both transgenic groups had a better effect on redifferentiation to some extent, as evidenced by higher expression levels of chondrogenic genes, suggesting the validity of combination with transgenic DCs and the microcavitary hydrogel on redifferentiation.

Progress in microsphere-based scaffolds in bone/cartilage tissue engineering.

Bone/cartilage repair and regeneration have been popular and difficult issues in medical research. Tissue engineering is rapidly evolving to provide new solutions to this problem, and the key point is to design the appropriate scaffold biomaterial. In recent years, microsphere-based scaffolds have been considered suitable scaffold materials for bone/cartilage injury repair because microporous structures can form more internal space for better cell proliferation and other cellular activities, and these composite scaffolds can provide physical/chemical signals for neotissue formation with higher efficiency.