A near-infrared responsive hydrogel loaded with Prussian blue-based nanocarriers for CO gas therapy of infected wounds

A NIR-responsive hydrogel loaded with Prussian blue-based nanocarriers and polydeoxyribonucleotides (PDRN) was proposed for the treatment of infected wounds . Carbon monoxide (CO)-releasing molecules were solidified in hollow Prussian blue nanoparticles via a phase change material and released after NIR triggering the photothermal conversion of Prussian blue. CO gas therapy demonstrated positive effects in antibacterial and anti-inflammatory aspects. Meanwhile, wounds showed accelerated healing under the action of PDRN. • Prussian blue nanocarriers achieve controlled release of carbon monoxide by near-infrared light. • Cationized polysaccharide and carbon monoxide endow the nanocomposite hydrogel with enhanced antibacterial effects. • Carbon monoxide and polydeoxyribonucleotides jointly exert immunomodulatory effects. • The polydeoxyribonucleotide accelerates wound healing by stimulating cell proliferation and growth. Infected wounds present difficulties in healing on account of persistent infection and inflammation, imbalance in the local microenvironment, as well as antibiotic resistance. Although carbon monoxide (CO) has the effect of inhibiting bacterial growth and reproduction, anti-inflammatory and promoting cell proliferation and differentiation, it faces major challenges to achieve its safe, effective and controlled release. Thereby, a Prussian blue (PB)-based nanocarrier loaded with CO-releasing molecules (CORMs) was prepared and encapsulated in a hydrogel for gas therapy of infected wounds . CO released under the trigger of near-infrared (NIR) light, along with the active factor polydeoxyribonucleotides (PDRN), plays a role in immunomodulation and promoting tissue proliferation. Simultaneously, CO and cationic-enhanced carboxymethyl chitosan (CMC), which constitute the hydrogel matrix, exerted an antibacterial function. In models of infected wounds, a rapid and high-quality wound healing was detected.