A review of synthesis, characterizations, and biological activity of amphiphilic copolymers containing pendant phosphorylcholine groups

Abstract

Pendant 2-(methacryloyloxy)ethyl phosphorylcholine (MPC) is a hydrophilic, biocompatible nanodrug, those are required for the preparation of patient-specific nanomedicine to enhance therapeutic efficacy in the human body. MPC combined with hydrophobic n-butyl methacrylate (BMA) or n-dodecyl methacrylate (DMA) with varying molecular weights and compositions obtained block (PMPCn-b-PBMAm and PMPCn-b-PDMAm; m and n represent degrees of polymerization) and random (P(MPC/BMAx) and P(MPC/DMAx); x represents composition) copolymers with reversible addition-fragmentation chain transfer (RAFT) radical polymerization. Their aggregation properties were evaluated by 1H NMR spectroscopy, fluorescence spectroscopy, static light scattering (SLS), dynamic light scattering (DLS), surface tension, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and in vitro anticancer activities. The 1H NMR data of PMPCn-b-PBMAm confirmed highly restricted motion of the n-butyl moiety through hydrophobic interactions between PMPC and PBMA blocks and established the restricted mobility of DMA and MPC pendant groups of P(MPC/DMAx), while MPC units were trapped in a hydrophobic micro domain. Hydrophobic probe pyrene was encapsulated in PMPCn-b-PBMAm micelles to exhibit fluorescence activity. Aggregation number increased with increasing ‘x’ due to the enhancement of hydrophobic interactions between n-dodecyl groups. SLS studies can exhibit structural properties of copolymer micelles by comprising a PBMA core with a PMPC shell. DLS studies demonstrated sizes of PMPCn-b-PBMAm micelles were gradually increased with increasing PBMA block lengths. Size, surface morphology, and thickness of bilayers were confirmed by SEM and TEM. Both copolymers are used as emerging candidates in biomedical research fields because the paclitaxel drug is incorporated in micelles; that’s why PMPC forms a biocompatible outer shell to exhibit stimuli-responsive drug efficacy and gene therapy.