Experimental study on the treatment of rabbit full-thickness articular cartilage defects by the new thermosensitive chitosan-based hydrogel containing SDF-1β, TGF-β1 in combination with subchondral bone drilling

Abstract

Objective To study the feasibility of the treatment of rabbitfull-thickness articular car tilage defects by the new thermosensitive chitosan-based hydrogel containing SDF-1 β, TGF-β1 in combination with subchondral bone drilling. Methods Experimental full-thickness articular cartilage defects were created in the condyles of the femurs of 24 rabbits. The 48 defects were randomly divided into 3 groups:(1) The new thermosensitive chitosan-based hydrogel containing SDF-1β, TGF-β1 in combination with subchondral bone drilling; (2) subchondral bone drilling alone; (3) no treatment as controls. The specimens were taken 4, 8, 12 weeks after operation for macroscopical observation, light and electromicroscopic examination and immunohistochemical analysis. Results Except for the control group in which the defects were repaired with only fibrous tissues, all defects of the other two groups were repaired by cartilage to some extents. The group of the new thermosensitive chitosan-based hydrogel containing SDF-1 β, TGF-β1 in combination with subchondral bone drilling gave better results than subchondral bone drilling alone in the aspects of cell morphology, type- Ⅱ collagen content and ultrastructure (P ＜ 0.05). Conclusion Combination of the new thermosensitive chitosan-based hydrogel containing SDF-1 β, TGF-β1 and subchondral bone drilling can well repair the full-thickness of articular cartilage defects in rabbits. Key words: Articular cartilage; Defects; Thermosensitive hydrogel; SDF-1 β; TGF-β1