Composite guar gum-silver nanoparticle hydrogels as self-healing, injectable, and antibacterial biomaterials

Biomaterial-based hydrogels incorporating antibacterial agents may provide sustainable solutions to biomedical device failures and the prevention of infections. Herein we report guar gum hydrogels, cross-linked with borax and loaded with silver nanoparticles, that are injectable, exhibit rapid self-healing, and show antibacterial properties towards both gram-positive and gram-negative bacteria. The hydrogels are fully characterized by infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and rheological measurements. An important focus was to minimize borax content, thus reducing the toxicity of the gels greatly, whilst retaining their favorable viscoelastic properties. When the low borax-content hydrogels are composited with curcumin-stabilized silver nanoparticles, the hydrogels show activity against Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), and Staphylococcus aureus (S. aureus).