A protein-based self-healing hydrogel for prolonged antimicrobial drug delivery with synergistic activity

Abstract

This study focuses on synthesizing an injectable and self-healing hydrogel from an abundant serum protein (bovine serum albumin, BSA) to control antimicrobial drug delivery impeding bacterial infections. Hydrogels were synthesized through a green synthesis route without using any crosslinking agent and characterized for their cross-linking, surface morphology, self-healing, viscoelasticity, injectability, and swelling and degradation properties. The prepared hydrogel has distinctive autofluorescence properties, as observed from the wavelength-dependent steady-state fluorescence spectral measurements. When lomefloxacin and doxycycline were incorporated into the hydrogel network, it allowed the controlled release of both antibiotics over at least 24 hours, with a release rate of over 90%. Hydrogels containing lomefloxacin and doxycycline were effectively used against E. coli and E. faecalis bacterial strains; their antibacterial effects were maintained for 24 hours. The live/dead cell test indicated that the hydrogel is effective against both (Gram-positive and Gram-negative) bacteria strains. Furthermore, our studies on bacteria encapsulation, specifically using E. coli, confirmed that the hydrogel is non-toxic, and the hydrogel demonstrates biocompatibility as the bacteria successfully grow within the hydrogel matrix. To assess biocompatibility, we conducted a cell attachment experiment with HEK 293 cells, and the results suggest that this hydrogel could be used for 3D cell culturing in the future.