Thermo-responsive PNIPAAm-b-PLA amphiphilic block copolymer micelle as nanoplatform for docetaxel drug release

In this study, a thermo-responsive poly(N-isopropylacrylamide-b-lauryl acrylate) (PNIPAAm-b-PLA) as a smart amphiphilic block copolymer was fabricated with tailored molecular weight through a controlled polymerization method, i.e., reversible addition-fragmentation chain-transfer (RAFT). Initially, the homopolymer of NIPAAm was synthesized and applied in the role of macroRAFT agent to copolymerize with LA monomer. The PNIPAAm-b-PLA nanosystem was self-assembled and organized stable nanomicelles with a low amount of critical micelle concentration (CMC) of 2.07 mg L-1 and small spherical dimensions. The anti-cancer therapeutic cargo, docetaxel (DTX) was encapsulated in a hydrophobic interior region of block copolymer (micelle core) via Van der Waals interactions with high loading efficiency. In vitro drug liberation profile from polymeric micelles demonstrated that DTX delivery was thermo-sensitive with a sustained drug release rate. The safety and anti-cancer effects of DTX and as-prepared micellar structures were investigated through an MTT assay on MCF-7 cells. The results exhibited that DTX loaded polymeric micelles revealed a comparable amount of toxicity to free drugs. It was concluded that this system emerges as a potentially favorable and powerful intracellular delivery of antitumor drug system in chemotherapy. [GRAPHICS] .