Antimicrobial chitosan nanodroplets: new insights for ultrasound-mediated adjuvant treatment of skin infection.

BACKGROUND

Chronic wounds, characterized by hypoxia, inflammation and impaired tissue remodeling, are often worsened by bacterial/fungal infections. Intriguingly, chitosan-shelled/decafluoropentane-cored oxygen-loaded nanodroplets (OLNs) have proven effective in delivering oxygen to hypoxic tissues.

AIM

The present work aimed at investigating nanodroplet antimicrobial properties against methicillin-resistant Staphylococcus aureus (MRSA) or Candida albicans, toxicity on human keratinocytes (HaCaT) and ultrasound (US)-triggered transdermal delivery.

MATERIALS & METHODS: Nanodroplet antibacterial/antifungal properties, human cytotoxicity, and US-triggered transdermal delivery were measured through microbiological, biochemical, and sonophoresis assays, respectively.

RESULTS

OLNs and oxygen-free nanodroplets (OFNs) displayed short- or long-term cytostatic activity against MRSA or Candida albicans, respectively. OLNs were not toxic to keratinocytes, whereas OFNs slightly affected cell viability. Complementary US treatment promoted OLN transdermal delivery.

CONCLUSION

As such, US-activated chitosan-shelled OLNs appear as promising, nonconventional and innovative tools for adjuvant treatment of infected chronic wounds.