Effect of biosurfactants on the self-assembly behavior and drug encapsulation for branched block copolymers

Abstract

For the past few years, block copolymers have attracted extensive attention in the field of drug delivery. In this work, the hyperbranched PEO-PPO block copolymer H1304 having the same PEO segments and PPO segments as the commercially available 4-branched block copolymer Tetronic1304 was synthesized. Compared with T1304, H1304 was characterized by lower cloud point, smaller critical micelle concentration (CMC), larger micellar size and better drug solubilization capacity. The effect of three biosurfactants lecithin (PC), alkyl glycogen (APG), sodium deoxycholate (NaDC) on the aggregation behavior of H1304 and T1304 were researched. Meanwhile, the solubilization and in vitro release properties of hydrophobic anticancer drug podophyllotoxin were also evaluated. The addition of PC or APG to form a mixed micelle reduced the cloud point and CMC, optimized the drug carrier characteristics. NaDC exhibited different effects due to its unique disclike surface structure. NaDC formed back-to-back aggregates, which interfered the self-assembly process of block copolymer and in turn caused variation of the copolymer micellar properties. The study of mixed systems consisting of biosurfactants and block copolymers will help to change the performance of copolymers in various pharmaceutical fields and contribute to the application of copolymers as drug carriers in drug delivery systems.