Preparation of multifunctional micelles from two different amphiphilic block copolymers

Micelles are widely used in drug delivery owing to their attractive properties such as controllable drug release rates and the ability to target certain locations by conjugating with specific molecules. However, with the current state of understanding, only the core–shell and corona sites of micelles can be utilized. To form a micelle, each block copolymer was dissolved in DMF and then dropped into a polar solvent. Polymer micelles were formed through the agglomeration of the hydrophobic part that constituted a non-polar core and a hydrophilic corona. In this study, poly(styrene)-block-poly(4-vinylpyridine) (PS-b-P4VP) and poly(styrene)-block-poly(acrylic acid) (PS-b-PAA) formed micelles with a PS core in water. The hydrophobic PS domains were insoluble in the aqueous phase, which led to aggregation. Furthermore, from the pH-sensitive characteristic of weak polyelectrolyte, the changing of pH condition has an affected to the degree of ionization. Due to their characteristics, we prepared micelles from block copolymers at various pH values to increase the functionality of the micelles.