Fast Gelation of Poly(ionic liquid)-Based Injectable Antibacterial Hydrogels.

Chengju Sheng,Chao Zhou,Che Zhao

doi:10.3390/gels8010052

Abstract

Traditional antibacterial hydrogels have a broad-spectrum bactericidal effect and are widely used as wound dressings. However, the biological toxicity and drug resistance of these antibacterial hydrogels cannot meet the requirements of long-term clinical application. Imidazolium poly(ionic liquids) (PILs) are polymeric antibacterial agents exhibiting strong antibacterial properties, as they contain a strong positive charge. In this study, two imidazolium PILs, namely poly(N-butylimidazolium propiolic acid sodium) (PBP) and poly(N-(3,6-dioxaoctane) imidazolium propiolic acid sodium) (PDP), as high efficiency antibacterial agents, were synthesized by polycondensation reaction. Then, the PILs were compounded with polyethylene glycol (PEG) by a thiol-yne click reaction to prepare injectable antibacterial hydrogels. An in vitro assay showed that the injectable antibacterial hydrogels could not only quickly kill Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), but also had low toxicity for human skin fibroblasts cells (HSFs) and human umbilical vein endothelial cells (HUVECs), respectively. Additionally, the lipopolysaccharide (LPS) inflammation model revealed that the injectable antibacterial hydrogels also had anti-inflammatory effects, which would be advantageous to accelerate wound healing.

Highlights

Injectable hydrogels have great application prospects in tissue engineering, because they have good water absorption, air permeability, and biocompatibility [1,2]
The Fourier transform infrared spectroscopy (FTIR) spectra in Figure S3a show that vibration peaks at 2200 cm−1 and 1700 cm−1 corresponded to –C≡C– and C=O, respectively, in both poly(Nbutylimidazolium propiolic acid sodium) (PBP) and PDP
These data confirmed that the targeted Poly(ionic liquids) (PILs) (PBP and PDP) were successfully synthesized

Summary

Introduction

Injectable hydrogels have great application prospects in tissue engineering, because they have good water absorption, air permeability, and biocompatibility [1,2]. The antibacterial mechanism of PILs involves positive imidazolium groups in the PILs attracting the negatively charged bacterial cell wall under the action of electrostatic force. PILs showed slow gelation and could not be injectable, which limited rial hydrogels containing PILs showed slow gelation and could not be injectable, which the application as wound in clinical practice. This work, we fabricated gelation and injectable antibacterial hydrogels, whichwhich wouldwould be wellbe adaptable to coverto fast gelation and injectable antibacterial hydrogels, well adaptable any irregularly infectedinfected wound wound completely in future situations. Two antibacterial imidazolium PILs, namely poly(N-butylimidazoliumpropropiolic piolicacid acid(PBP). Alkynyl) were crosslinked with 4 arm thiol PEG (4 arm PEG-SH) to fabricate fast gelation and antibacterial hydrogels by thiol-yne clickclick reaction

Structure of Synthesized PILs

The Gelation and Physical Properties of Injectable Hydrogels

In Vitro Antibacterial and Antibiofilm Activities of Injectable Hydrogels

Both HB and HD exhibited taining imidazolium

In Vitro Cytotoxicity of Injectable Hydrogels

InHemolysis

Conclusions

Materials and

Synthesis of PEG-SH and PEG-Alkynyl

Synthesis of PBP and PDP

Preparation of Antibacterial Hydrogels

Characterization of PILs and Hydrogels