A hydrothermally transformed multifunctional proteinaceous nanoparticle biosealant with intrinsic light-responsive redox cycling for self-sterilizing and accelerated wound healing

Abstract

Mouldable tissue sealants with optimal adhesion and cohesion remain an active research focus, with a few commercial options, but none offering inherent therapeutic benefits. We report a novel fluorescent proteinaceous nanoparticle (PNP)-based nanosealant, derived from co-nanotization of gelatin and acrylamide through a green synthesis route, which demonstrates intrinsic therapeutic attributes for accelerated wound healing, together with the desirable tissue-reinforcement properties expected of a biosealant. PNPs were synthesized through in situ crosslinking via controlled aqueous-phase hydrothermal crosslinked polymerization (HTCP) of the aforementioned substrates, followed by tannic acid grafting to yield the final PNP sealant. The core–shell PNP and surface functionalities modulate photophysical enhancement, influence carbonization for balanced cohesion/adhesion, and aid redox regulation. The PNP sealant's enriched optical traits enable dual functionality: inherent blue fluorescence for real-time tissue tracking and low-intensity visible-light activation (40 W white LED) to generate reactive oxygen species (ROS) on demand. This allows self-sterilization through rapid photodynamic inactivation of Gram-positive and Gram-negative bacteria. Most notably, the PNP sealant could also scavenge ROS under ambient conditions, imparting the much-coveted ability to regulate ROS without any external agents or metal ions. In vivo studies with rabbits establish the PNP sealant as a pro-sealing material (∼1.48 MPa strength) that heals wounds within a week, outperforming both commercial variants and traditional suturing. The adhesive nanoformulation surpasses these controls at every stage of healing by enhancing collagen deposition, aligning fibroblasts, and reducing inflammation, which promotes endothelial proliferation and organized vascular remodelling. This low-cost synthesis approach effectively converts regenerative substrates into bio-nanosealants with strong potential as light-responsive, multifunctional platforms offering precise control over oxidative stress applicable well beyond wound healing.