Bioreducible, hydrolytically Degradable and Targeting Polymers for Gene Delivery
Recently, synthetic gene carriers have been intensively developed owing to their promising application in gene therapy and considered as a suitable alternative of viral vectors because of serval benefits. But the cationic polymers still face some problems like low transfection efficiency, cytotoxicity, and poor cell recognition and internalization. The emerging engineered and smart polymers can respond to some change in the biological environment like pH change, ionic strength change and redox potential, which is beneficial for cell uptake. The redox-sensitive disulfide based and hydrolytically degradable cationic polymers serve as gene carriers with an excellent transfection efficiency and good biocompatibility owing to the degradation in cytoplasm. Additionally, the biodegradable polymeric micelles with cell-targeting function are the recently emerging gene carriers, especially for the transfection of endothelial cells. In this review, some strategies for gene carriers based on these bioreducible and hydrolytically degradable polymers will be illustrated.