Stimuli-responsive degradation of amphiphilic block copolymer (ABP) micelles is highly desired in the development of multifunctional nanomaterials. For polymer-based drug delivery applications, the degradation enables fast and controlled release of encapsulated therapeutics from the delivery vehicles in targeted cells. It also ensures clearance of the empty device after drugs are delivered in the body. This chapter reviews the recent development of new methods to synthesize three types of reductive (thiol-responsive) degradable ABP micelles having different numbers and types of disulfides positioned at various locations. These new ABPs were prepared by a combination of atom transfer radical polymerization (ATRP) with polycondensation or anionic ring opening polymerization (ROP). Due to the amphiphilic nature, these ABPs formed, through aqueous self-assembly, colloidally stable micelles with hydrophobic cores surrounded with hydrophilic coronas. The micelles exhibit rapid and controlled response to reductive reactions, enhancing the release of encapsulated model drugs as well as leading to the significant change in morphologies. In a biomedical perspective, the micelles were non-toxic to various cell lines, and hence biocompatible.
展开▼
