Experimental Study of Chitosan Mediated In Vivo igf-1 Gene Transfection for The Treatment of Cartilage Defect (Local Administration of Chitosan/igf-1 Complex Treat Cartilage Defect)

Cartilage damage is difficult to repair,as a major stimulator of matrix synthesis in cartilage, insulin-like growth factor I (IGF-I) is likely to play a important role in the process of repairing cartilage damage. To study the in vivo therapeutic effect of chitosan mediate igf-lgene transfection on repairing articular cartilage defect in rabbits.Chitosan-DNA nanoparticlesCS/
igf-1
were prepared following the principle of complex coacervation and cartilage defect in keen joint ectocondyle were created in adult rabbits. Twenty four experimental knees joints from twelve rabbits were divided into four groups, one sham-operated and NS treated group, and three cartilage defect groups received treatments of CS/
igf-1
, CS alone and PBS respectively. All the rabbits were subjected to sacrifice after four weeks treatment. Cartilage chips collected from rabbit joints were used for real-time quantitative PCR and histological evaluation to detect the expressions of cartilage repairing associated genes and tissue repairing status. These experiments showed that compared with normal control group, the expressions of
type

II

collagen
and
aggrecan
were increased in all cartilage defected groups, however, the highest expression was observed in (CS/
igf-1
) treated group. For histological evaluation, (CS/
igf-1
) treatment leaded to the best recruit. Taken together, these observations confirm that local chitosan mediated
igf-1
gene transfer to joints could serve as a therapeutic strategy to stimulate new matrix synthesis and to promote the reparation of the injured articular cartilage
in

vivo
.