Self-Assemblies of Thermoresponsive Poly(N-vinylcaprolactam) Polymers for Applications in Biomedical Field

Abstract

Poly­(N-vinylcaprolactam) (PVCL) is a temperature-responsive polymer with a lower critical solution temperature (LCST) in the physiological range. PVCL’s unique features include thermosensitivity controlled by concentration and molecular weight, as well as excellent biocompatibility and nontoxicity. In comparison to other thermosensitive polymer structures, PVCL-based materials have been much less investigated. This Spotlight focuses on PVCL materials whose nanostructure can be precisely controlled during self-assembly in aqueous solutions. Recent developments in synthesis of amphiphilic PVCL-containing polymers including random, diblock, and triblock copolymers are reviewed. We overview templated and solution-based self-assembly approaches developed in our group to present thermosensitive assemblies ranging from thin coatings and hydrogels to micelles, polymersomes, nanogels, and capsules. The fundamental issues related to their structure–property relationships for temperature, pH, and enzymatic sensitivity are discussed, and their impact on applications in the biomedical field are emphasized. Finally, we outline the prospects of PVCL constructs to be developed in advanced materials with on-demand properties.

Synthesis, Thermoresponsive Behavior, and Catalytic Properties of Amphiphilic Diblock Copolymers of N-Vinylcaprolactam and N-Vinylimidazole

“…Stimuli-responsive or smart amphiphilic copolymers are capable of changing their morphology in response to various external stimuli, such as temperature, quality of the solvent, pH, and ionic strength [1][2][3][4][5]. Among them, thermosensitive copolymers demonstrating a lower critical solution temperature (LCST) near physiological temperatures, which stratify from aqueous solutions upon heating and recover their solubility after cooling, have received considerable attention owing to potential practical application in targeted drug delivery systems or as nanocontainers for chemical and biochemical reactions [6][7][8][9].…”

Polymer-Based Smart Drug Delivery Systems for Skin Application and Demonstration of Stimuli-Responsiveness

“…PVCL is a temperature-responsive polymer with an LCST in the physiological range (~32-37 °C). PVCL polymers attract high interest because of PVCL solubility in aqueous and organic solutions, as well as strong hydrophilicity and nontoxicity compared with PNIPAM [ 115 , 116 ]. Zavgorodnya and coworkers prepared temperature-responsive hydrogel films of PVCL for topical drug delivery.…”

Thermoresponsive Polymers Based on Tertiary Amine Moieties

“…Up to now, tremendous achievements have been made in the exploration of thermoresponsive polymers. Various LCST‐type thermoresponsive polymers based on hydrogen bonding have been reported, [ 33–58 ] such as poly( N ‐isopropylacrylamide) (PNIPAM) and its analogues, [ 33–41 ] poly( N ‐vinylcaprolactam), [ 42–45 ] poly(2‐oxazoline)s, [ 46–50 ] oligo(ethylene glycol)‐containing polymers, [ 51–54 ] and poly(vinyl ether)s, [ 55–59 ] etc. In comparison, UCST‐type thermoresponsive polymers are relatively uncommon.…”