Mixed micelles self-assembled from block copolymers for drug delivery

Mixed micelles self-assembled from two or more dissimilar block copolymers provide a direct and convenient approach to improve physical stability and enhance drug loading capacities of conventional polymeric micelles for drug delivery. The versatility of this approach also allows for the concomitant integration of multiple functionalities into a single system — a feat that is synthetically challenging to accomplish with micelles formed from a single co-polymer. Through the careful selection and blending of structurally and/or functionally diverse block copolymers, a population of novel and multi-functional micelles bearing desirable attributes of each constituent copolymer can be easily fabricated without the need for elaborate synthetic schemes. As such, this review is focused on the various strategies used to form and stabilize mixed micelles for drug delivery and the methodologies employed to ascertain the establishment of mixed micelle formation. In vivo evidence demonstrating the effectiveness of mixed micelles will be presented. Lastly, future perspectives for the development of mixed micelle systems for drug delivery will also be discussed.