Effective modulation of transforming growth factor-ß1 expression through engineered microRNA-based plasmid-loaded nanospheres.

BACKGROUND AIMS: Sustained gene delivery could be particularly necessary in modulating gene expression in healing intrasynovial tendons and may be a promising approach for preventing adhesions. METHODS: Polylactic-co-glycolic acid nanospheres were prepared and were then incorporated with plasmids expressing enhanced green fluorescence protein and miRNA for inhibiting the transforming growth factor-ß1 gene expression. RESULTS: We demonstrated that cultured tenocytes could be effectively transfected by means of nanosphere/plasmid. The expression of transforming growth factor-ß1 is significantly downregulated in healing chicken flexor tendon treated with nanosphere/plasmid. Histology analysis did not demonstrate any significant inflammation or necrosis in tendons injected with nanosphere/plasmid after surgery. CONCLUSIONS: Nanosphere/plasmid may be a promising non-viral vector for gene therapy of the injured flexor tendon.