Wound healing hydrogel based on natural substrances

Abstract

In this study, a series of multifunctional polymeric hydrogels was designed and synthesized by combining a biodegradable polyester backbone based on glycerol, divinyl adipate, and xylitol with a bioinspired crosslinking system composed of polydopamine–polyethylenimine (PDA–PEI) complexes. Structural characterization by NMR and FTIR spectroscopy confirmed the successful incorporation of benzaldehyde-modified units and the formation of covalent and supramolecular bonds responsible for the stability of the polymer network. Swelling experiments revealed a clear dependence of water uptake and dimensional stability on the crosslinker concentration. Higher PDA–PEI contents led to denser and more stable networks, while lower levels provided higher swelling capacity. Antioxidant tests using DPPH (2,2-diphenyl-1-picrylhydrazyl) radical demonstrated a strong correlation between crosslinker content and radical scavenging activity, attributed to the catechol and amine functionalities of PDA–PEI. Antibacterial evaluations confirmed broad-spectrum efficacy against both Gram-positive and Gram-negative bacteria, including Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The combined results demonstrate that the developed PDA–PEI-crosslinked polyesters form robust, bioactive hydrogel systems with tuneable physicochemical and biological properties. Their simultaneous antioxidant and antimicrobial performance, along with good swelling stability, make them promising candidates for biomedical applications such as wound healing, tissue scaffolds, and controlled drug release systems.