Antibiotic biocompatibility assay and anti-biofilm strategies for Pseudomonas aeruginosa infection in bioengineered artificial skin substitutes.

Objectives: Bioengineered artificial skin substitutes (BASS) are an advanced therapy for treating extensively burned patients. Pseudomonas aeruginosa (P. aeruginosa) infections represent a major challenge in these patients as formation of biofilms impede wound healing and perpetuate a chronic inflammatory state. Here we assessed antibiotics (alone or in combination) with respect to cytotoxicity, as well as antimicrobial efficacy in P. aeruginosa biofilm formed on infection of BASS.
Methods: Cell viability, structure and functionality were evaluated using microscopy and trans-epidermal water loss analyses, respectively. BASS were established and infected for 24 h to allow P. aeruginosa biofilm formation, after which two antimicrobial approaches, treatment and prevention, were tested. In the latter, antibiotics were added to BASS before infection. The antimicrobial effect was determined using real-time calorimetry.
Results: In dose-response experiments, 1.25 mg/mL amikacin, 0.02 mg/mL ciprofloxacin, 0.051 mg/mL colistin, 1 mg/mL meropenem and colistin in combination with either amikacin, ciprofloxacin and meropenem did not affect BASS' viability, structure and functionality. All antibiotics, except colistin, showed effective antimicrobial activity at these non-cytotoxic concentrations. For concentrations below the highest non-cytotoxic ones, successive treatments resulted in higher bacterial metabolic rates. Only the combinations managed to eradicate the infection with repeated treatments. With respect to prevention of infection, all antibiotics at the highest non-cytotoxic concentrations and the combinations were effective. This preventive capacity was maintained for at least 5 days.
Conclusion: The findings highlight the potential for developing BASS with antimicrobial properties that can prevent infections during wound healing in burn patients.
(© The Author(s) 2024. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)