Multifunctional zwitterionic microneedle dressings for accelerated healing of chronic infected wounds in diabetic rat models.

Diabetic infected wounds are one of the major threats to public health but traditional wound dressings always have poor therapeutic efficacy influenced by the single treatment principle and limited penetration depth. Herein, we developed a novel kind of multifunctional degradable and removable zwitterionic microneedle dressings that could achieve multi-effective treatment of diabetic chronic wounds with a single dressing application. The substrates of microneedle dressings are composed of zwitterionic polymer polysulfobetaine methacrylate (PSBMA) and photothermal hair particles (HMPs), which can absorb wound exudate, form a barrier to the bacterial environment for the wound and exhibit an excellent photothermal bactericidal effect to promote wound healing. By loading zinc oxide nanoparticles (ZnO NPs) and asiaticoside in needle tips, drugs could diffuse in the wound area as the tips degrade to achieve highly effective antibacterial and anti-inflammatory effects and promote deep wound healing and tissue regeneration. The microneedles (MNs) were applied in diabetic rats with Staphylococcus aureus -infected wounds to demonstrate that the combination of drug and photothermal multi-treatment has accelerated tissue regeneration and collagen deposition and significantly promoted wound healing.