Construction of osteo-chondro interface using chondrocyte-based living scaffold

Abstract

Hydrogels have become a popular biomaterial in engineered regenerative medicine, in which they are used as scaffolds, drug delivery system, biosensors, etc. due to their unique and versatile advantages. However, challenges remained unsolved when incorporating hydrogels with anchorage- dependent cells (ADCs), for example, mesenchymal stem cells, osteoblasts. In this project, a three- dimensional (3D) chondrocyte- based living scaffold was developed, following the formation of microcavity hydrogel- phase transfer cell culture (MCG- PTCC) model to provide ‘anchors’ for osteoblasts to attach, spread, proliferate, differentiate and function. The model was inspired from the observation of edge flourish phenomenon, in which chondrocytes appeared with high density at gel- cavity interface. Osteoblasts were then cultured in the living scaffold and promoted to differentiate. The compatibility between osteoblasts and chondrocyte- based scaffold was thoroughly evaluated through biochemical assays, histology, immunofluorescent staining and real- time polymerase chain reaction (RT- PCR). In summary, in comparison with the conventional approach, the three dimensional chondrocyte- based living scaffold was superior in providing osteoblasts, the anchorage- dependent cell, of high viability, favourable morphology and normal functionalities, resulting in calcium deposition and bone matrix mineralization- early stages of endochondral ossification process.