Facile Glycerol-Assisted Synthesis of N-Vinyl Pyrrolidinone-Based Thermosensitive Hydrogels via Frontal Polymerization

Abstract

We report a facile strategy for quickly fabricating thermosensitive poly(HPMA-co-NVP) hydrogels in the presence of glycerol by using frontal polymerization (FP). The appropriate amounts of hydroxypropyl methacrylate (HPMA) and 1-vinyl-2-pyrrolinone (NVP), N,N 0 -methylenebisacrylamide (MBAA), and ammonium persulfate (APS)/N,N,N 0 ,N 0 -tetramethylethylenediamine (TMEDA) couple redox initiator were mixed together at ambient temperature in the presence of glycerol as the medium. A variety of features for preparing hydrogel samples, such as ratios of NVP/ HPMA, the presence of the glycerol and its concentration, and MBAA cross-linker concentration, were thoroughly investigated. We have found that the presence of glycerol can suppress the "fingering" of FP and overcome the formation of bubbles. Also, the ratio of NVP/HPMA for synthesis of hydrogels by FP plays an important role in its microstructure and swelling property. The morphology, thermosensitive behavior, and swelling studies of polymer hydrogels prepared via FP are comparatively investigated on the basis of environmental scanning electron microscopy (ESEM) and swelling measurement. Results show that the swelling capacity of the hydrogel prepared via FP is superior to that obtained by the traditional batch polymerization (BP) method. The glycerol-assisted FP can be exploited as an alternative means for synthesis of NVP-based copolymer hydrogels with additional advantages of fast and efficient way.

Influence of monomer and crosslinker molar ratio on the swelling behaviour of thermosensitive hydrogels

“…Hydrophilic polymer of HPMet has the excellent biocompatibility and the similarity of its physical and chemical properties with the living tissues, satisfactory chemical and hydrolytical stability and good tolerance by the cells [30][31][32]. It was widely used in immunocytochemical processes.…”

Robust Self-Healing Hydrogels Assisted by Cross-Linked Nanofiber Networks

“…The redox reaction of APS and TEMED can give two types of primary radical species from amine and persulfide (Supplementary Fig. S1), initiating cross-linking reaction and profiting the formation of hydrogel networks252627. To enhance healing performance of hydrogels, an electrospinning technique, a cost-effective approach for facile generation of nano-/micro-fibrous polymers2829303132, was employed to prepare a cross-linked nanofiber bilayer film filled with both oxidant and reductant as a healing layer.…”

Hyperbranched poly(amine-ester) based hydrogels for controlled multi-drug release in combination chemotherapy

“…In our hydrogel system, polymerization could occur quickly at room temperature and at body temperature with a small amount of APS but no reductant added as catalyst. The possible reason is that APS and tertiary amine in the structure of HPAE form a redox system as initiator, which is similar to APS with the catalyst TMEDA [49]. Fig.…”