Recent Advances in Thermoresponsive OEGylated Poly(amino acid)s.

Chao Geng,Shixue Wang,Hongda Wang

doi:10.3390/polym13111813

Chao Geng, Shixue Wang + Show 1 more

Open Access

https://doi.org/10.3390/polym13111813

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Abstract

Thermoresponsive polymers have been widely studied in the past decades due to their potential applications in biomedicine, nanotechnology, and so on. As is known, poly(N-isopropylacrylamide) (PNIPAM) and poly(oligo(ethylene glycol)methacrylates) (POEGMAs) are the most popular thermoresponsive polymers, and have been studied extensively. However, more advanced thermoresponsive polymers with excellent biocompatibility, biodegradability, and bioactivity also need to be developed for biomedical applications. OEGylated poly(amino acid)s are a kind of novel polymer which are synthesized by attaching one or multiple oligo(ethylene glycol) (OEG) chains to poly(amino acid) (PAA).These polymers combine the great solubility of OEG, and the excellent biocompatibility, biodegradability and well defined secondary structures of PAA. These advantages allow them to have great application prospects in the field of biomedicine. Therefore, the study of OEGylated poly(amino acid)s has attracted more attention recently. In this review, we summarized the development of thermoresponsive OEGylated poly(amino acid)s in recent years, including the synthesis method (such as ring-opening polymerization, post-polymerization modification, and Ugi reaction), stimuli-response behavior study, and secondary structure study. We hope that this periodical summary will be more conducive to design, synthesis and application of OEGylated poly(amino acid)s in the future.

Highlights

Stimuli-responsive polymers, so called “smart polymers” that can be triggered by a variety of external environmental stimuli such as temperature, pH, light, ionic, chemical and biological stimuli etc., and with the change of physical and chemical properties, have been extensively investigated because of their potential applications in the past few decades [1,2,3,4,5,6,7,8,9,10,11,12]
Thermoresponsive behaviors of polymers can be generally classified into two categories, lower critical solution temperature (LCST) type and upper critical solution temperature (UCST) type based on the equilibrium phase separation [16]
Thermoresponsive OEGylated poly(amino acid)s combined the advantages of oligo(ethylene glycol) (OEG) and poly(amino acid)s with great solubility, excellent biocompatibility and well-defined secondary structures

Summary

Introduction

Stimuli-responsive polymers, so called “smart polymers” that can be triggered by a variety of external environmental stimuli such as temperature, pH, light, ionic, chemical and biological stimuli etc., and with the change of physical and chemical properties, have been extensively investigated because of their potential applications in the past few decades [1,2,3,4,5,6,7,8,9,10,11,12]. Thermoresponsive behaviors of polymers can be generally classified into two categories, lower critical solution temperature (LCST) type and upper critical solution temperature (UCST) type based on the equilibrium phase separation [16]. In both types, phase separation will occur and result in a turbid mixture of the two phases at a concentration dependent cloud point temperature (Tcp), with Tcp ≥ LCST for separation with increasing temperature or Tcp ≤ UCST for separation with decreasing temperature, and a single phase for temperatures intermediate to these two regimes.

Synthetic Method

Applications

Conclusions and Outlook