# Biomedical Interpenetrated Hydrogels Fabricated via Quaternary Ammonium Chitosan and Dopamine-Conjugated Gelatin Integrated with Genipin and Epigallocatechin Gallate

## TL;DR

This paper introduces a new type of biomedical hydrogel with self-healing, antibacterial, and cell-friendly properties for tissue regeneration.

## Contribution

A novel interpenetrated hydrogel is developed using dopamine-gelatin and quaternary ammonium chitosan with EGCG for multifunctional biomedical use.

## Key findings

- The hydrogels show self-healing properties and strong adhesion to various materials and organs.
- They exhibit antibacterial activity against Escherichia coli and Staphylococcus aureus.
- The hydrogels have good antioxidant activity, hemocompatibility, and cell migration ability.

## Abstract

Multifunctional hydrogels with an interpenetrated network structure have shown great potential for biomedical and tissue-regeneration applications. In this work, the biomedical hydrogel was fabricated with an interpenetrated network based on dopamine grafted gelatin (DA-Gel), and genipin crosslinked quaternary ammonium chitosan (QCS), incorporating epigallocatechin gallate (EGCG). The EDC/NHS and Schiff-base bond connections occurred in the hydrogels, as confirmed by Fourier-transform infrared (FT-IR) analysis. The properties of the fabricated hydrogels, including microstructure, degradation rate, adhesive strength, mechanical strength, and rheological behavior, can be regulated by adjusting the DA-Gel/QCS ratio or by using different crosslinking approaches. In addition, the fabricated hydrogels exhibited self-healing properties and strong adhesion to various materials and organs. Furthermore, the hydrogels performed good antibacterial activity against the typical bacteria, Escherichia coli and Staphylococcus aureus. EGCG encapsulated hydrogels displayed excellent antioxidant activities and good hemocompatibility. The hydrogels also demonstrated excellent cytocompatibility and good cell migration ability. The above results provide a facile approach to fabricate the biomedical hydrogels with a regulated network structure and multifunctional characteristics with potential in biomedical applications.