Octopus-Inspired Adaptive Molecular Motion for Synergistic Photothermal and Nitric Oxide Antibacterial Therapy in Diabetic Wound Repair

Bacterial infections, especially those from drug-resistant strains, pose a significant threat to healing diabetic skin injuries, with current treatments being intricated and often unsatisfactory. Inspired by octopuses, a biomimetic material using α-cyclodextrin (α-CD) and polyethylene glycol (PEG) assembled with graphene oxide end-capped polyrotaxanes (GO-PR) is developed, where α-CD mimics the flexible tentacles of an octopus. Further, α-CD is cationically modified with polyethyleneimine (PEI) to resemble octopus suction cups, creating GO-PRP, which effectively captures and adheres to bacteria. Importantly, to emulate an octopus's ink defense, GO-PRP is used as a carrier for nitric oxide (NO), resulting in GO-PRP/NONOate. Utilizing the photothermal conversion of GO, near-infrared light exposure triggers rapid heating and NO release, providing efficient antibacterial activity and biofilm dispersion, significantly reducing inflammation in diabetic skin injuries in type I rats. During wound healing, sustained NO release promotes vascular endothelial growth factor production and blood vessel regeneration, enhancing collagen formation and shortening the healing time for diabetic skin infections. Thus, octopus-inspired GO-PRP/NONOate emerges as a novel biomaterial for treating drug-resistant bacterial infections in diabetic wounds in the biomedical field.