Antibiofilm activity of polyethylene glycol-quercetin nanoparticles-loaded gelatin-N,O-carboxymethyl chitosan composite nanogels against .

Background: Biofilms, such as those from , are generally insensitive to traditional antimicrobial agents, making it difficult to inhibit their formation. Although quercetin has excellent antibiofilm effects, its clinical applications are limited by the lack of sustained and targeted release at the site of infection.

Objectives: Polyethylene glycol-quercetin nanoparticles (PQ-NPs)-loaded gelatin-N,O-carboxymethyl chitosan (N,O-CMCS) composite nanogels were prepared and assessed for the on-demand release potential for reducing biofilm formation.

Methods: The formation mechanism, physicochemical characterization, and antibiofilm activity of PQ-nanogels against were studied.

Results: Physicochemical characterization confirmed that PQ-nanogels had been prepared by the electrostatic interactions between gelatin and N,O-CMCS with sodium tripolyphosphate. The PQ-nanogels exhibited obvious pH and gelatinase-responsive to achieve on-demand release in the micro-environment (pH 5.5 and gelatinase) of . In addition, PQ-nanogels had excellent antibiofilm activity, and the potential antibiofilm mechanism may enhance its antibiofilm activity by reducing its relative biofilm formation, surface hydrophobicity, exopolysaccharides production, and eDNA production.

Conclusions: This study will guide the development of the dual responsiveness (pH and gelatinase) of nanogels to achieve on-demand release for reducing biofilm formation.