Self-assembled photothermal conversion shell coating on the surface of CA/SP for photothermal bacteriostasis and rapid wound healing

Near-infrared light-triggered photothermal therapy (PTT) has attracted extensive attention in the field of antibacterial research. This therapy confers advantages such as tissue penetration and acceleration of tissue regeneration . Tannic acid/Fe (TA/Fe), a green gold organic complex, displays excellent photothermal conversion and adhesion abilities. In this study, TA/Fe was assembled on surface of composite microspheres (CA/SP) based hydrogen bond interaction to prepare a novel microsphere dressing (CA/SP@TA/Fe) that shows well photothermal conversion capability and biocompatibility. After 5 cycles of NIR light irradiation , the microspheres still maintain a good warming rate. Under the synergistic effect of NIR, CA/SP@TA/Fe+NIR can greatly improve the antibacterial performance of CA/SP@TA/Fe, exhibiting inhibition rates for Streptococcus aureus and Pseudomonas aeruginosa are over 99 %. In addition, CA/SP@TA/Fe also showed excellent hemostatic ability and accelerated the total healing of cortical injury wounds, with wound closure reaching 92.58 % and 98.54 % on days 7 and 15 of healing. Therefore, CA/SP@TA/Fe microsphere dressings show potential for application as wound dressings.