Stimuli‐Responsive Amino Acid Based Polymeric Nanomicelles With Antimicrobial and Anticancer Activities

ABSTRACT Herein this work, a biocompatible polymer synthesis approach has been established for the designing of α‐methoxy‐ω‐amino poly(ethylene glycol)‐L‐glutamate‐L‐aspartate [MeO‐PEG‐NH‐ b ‐(L‐GluA) 5 ‐ b ‐(L‐AspA) 18 ]/[PEG‐ b ‐PBLG‐ b ‐PBLA] triblock copolymeric nanomicelles by using α‐methoxy‐ω‐amino PEG as a macro initiator via modified ring‐opening polymerization. The colloidal stability, remarkable protein folding properties, and distinct morphology of the prepared polymer are confirmed. The microscopic analysis confirms the formation of nanomicelles with an average diameter of 13 nm to 22 nm for [PEG‐ b ‐PBLG‐ b ‐PBLA] and [PEG‐ b ‐PBLG], respectively. The copolymers show an effective influence on self‐assembly behavior with respect to change in temperature and pH. The cellular inhibition properties of the block copolymeric micelles is confirmed through in vitro study against the MDA‐MB‐231 cancer cells. The calculated IC 50 values for [PEG‐b‐PBLG] and [PEG‐ b ‐PBLG‐ b ‐PBLA] copolymers are found to be 560.340 ± 34.107 μg/mL and 750.468 ± 47.312 μg/mL, respectively. The minimum inhibitory concentration (MIC) for antibacterial activity is calculated to be 0.8 μg /mL against gram (−) Escherichia coli ( E . coli ) of triblock copolymer. Therefore, the attachment of a new amino acid block in the [PEG‐ b ‐PBLG‐ b ‐PBLA] copolymer enhances the thermal stability, protein folding properties, colloidal stability, antibacterial activities, and biocompatibility, on account of which the synthesized triblock copolymer nanomicelle could be beneficial for antimicrobial and anticancer activities.