Sprayed PAA-CaO₂ nanoparticles combined with calcium ions and reactive oxygen species for antibacterial and wound...

The most common socioeconomic healthcare issues in clinical are burns, surgical incisions and other skin injuries. Skin lesion healing can be achieved with nanomedicines and other drug application techniques. This study developed a nano-spray based on cross-linked amorphous calcium peroxide (CaO₂) nanoparticles of polyacrylic acid (PAA) for treating skin wounds (PAA-CaO₂ nanoparticles). CaO₂ serves as a 'drug' precursor, steadily and continuously releasing calcium ions (Ca²⁺) and hydrogen peroxide (H₂O₂) under mildly acidic conditions, while PAA-CaO₂ nanoparticles exhibited good spray behavior in aqueous form. Tests demonstrated that PAA-CaO₂ nanoparticles exhibited low cytotoxicity and allowed L929 cells proliferation and migration in vitro. The effectiveness of PAA-CaO₂ nanoparticles in promoting wound healing and inhibiting bacterial growth in vivo was assessed in SD rats using full-thickness skin defect and Staphylococcus aureus (S.aureus)-infected wound models based thereon. The results revealed that PAA-CaO₂ nanoparticles demonstrated significant advantages in both aspects. Notably, the infected rats' skin defects healed in 12 days. The benefits are linked to the functional role of Ca²⁺ coalesces with H₂O₂ as known antibacterial and healing-promoted agents. Therefore, we developed nanoscale PAA-CaO₂ sprays to prevent bacterial development and heal skin lesions.