Collagen-based porous scaffolds containing PLGA microspheres for controlled kartogenin release in cartilage tissue engineering

A scaffold composed of different collagen (COL)/chitosan (CS)/hyaluronic acid sodium (HAS) salt ratios was evaluated by determining porosity, swelling, loss rate in hot water, mechanical property, and cell proliferation to obtain optimum conditions for manufacturing porous scaffolds. Results showed that the optimal ratio of COL/CS/HAS salt porous scaffold was 1:1:0.1. High swelling and loss rate of scaffolds/microspheres (MPs) could lead to high diffusion rate of MPs from the scaffolds, causing an increase in the kartogenin (KGN) release. The porous scaffolds at optimum conditions had a maximum amount of KGN release. Results of in vitro fluorescence staining and cell proliferation suggested that scaffolds/MPs had good biocompatibility and the capability to promote bone marrow stromal cell proliferation, cartilage tissue regeneration, and integration between the repaired and surrounding cartilages. Therefore, this composite could be a promising material for cartilage repair and regeneration, which could be effective in the knee osteoarthritis treatment.