Background: The treatment of Staphylococcus aureus  (S. aureus )-infected wounds is difficult. It causes extreme pain to tens of thousands of patients and increases the cost of medical care. The antimicrobial peptide OH-CATH30 (OH30) has a good killing activity against S. aureus  and can play a role in accelerating wound healing and immune regulation. Therefore, it shows great potential for wound healing.
Purpose: The aim of this study was to overcome the short half-life and easy enzymolysis of OH30 by using graphene oxide conjugated with polyethylene glycol to load OH30 (denoted as PGO-OH30), as well as to evaluate its effect on wounds infected by S. aureus.
Methods: PGO-OH30 nanoparticles were prepared by π–π conjugation and characterized. Their cell cytotoxicity, cell migration, infectious full-thickness dermotomy models, and histopathology were evaluated.
Results: Characterization and cytotoxicity experiments revealed that the PGO-OH30 drug-delivery system had good biocompatibility and excellent drug-delivery ability. Cell-migration experiments showed that PGO-OH30 could promote the migration of human immortalized keratinocytes (HaCaT) cells compared with the control group (P < 0.05). In a mouse model of skin wound infection, PGO-OH30 accelerated skin-wound healing and reduced the amount of S. aureus  in wounds compared with the control group (P < 0.05). In particular, on day 7, the number of S. aureus  was 100 times lower in the PGO-OH30 group than in the control group.
Conclusion: The PGO-OH30 drug-delivery system had good biocompatibility and excellent drug-delivery ability, indicating its good therapeutic effect on a skin wound-infection model.
Keywords: OH-CATH30, bacterial infection, graphene oxide, skin wound