Sonophotodynamic inactivation of Pseudomonas aeruginosa biofilm mediated by curcumin

Abstract

The inactivation of Pseudomonas aeruginosa biofilm is a major challenge, as biofilms are less responsive to conventional treatments and responsible for persistent infections. This has led to the investigation of alternative approaches for biofilm control such as photodynamic (PDI) and sonodynamic (SDI) inactivation. The combination of them, known as Sonophotodynamic Inactivation (SPDI), has improved the effectiveness of the process. Curcumin, a well-established photosensitizer, has been identified as a potential sonosensitizer. This study evaluated the most effective combination for SPDI against P. aeruginosa biofilms in vitro, varying curcumin concentrations and ultrasound intensities. The results indicated that the inactivation was directly proportional to the curcumin concentration. Using curcumin 120 µM and 3.0 W.cm⁻² of ultrasound intensity, SPDI demonstrated the highest and the best synergistic results, equivalent to 6.9 ± 2.1 logs of reduction. PDI reduced 0.7 ± 0.9 log and SDI had no effect. In conclusion, SPDI with curcumin is a promising approach for biofilm inactivation.

Keywords:

• Sonodynamic
• ultrasound
• photodynamic
• light
• Curcumin
• Pseudomonas aeruginosa
• biofilm

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was funded by Brazilian Funding Agencies: Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) [Finance Code 001]; National Council for Scientific and Technological Development - CNPq [465360/2014-9, 306919/2019-2; 305072/2022-6, 131017/2022-5, 440237/2021-1]; São Paulo Research Foundation (FAPESP) grants [2013/07276-1 (CePOF), 2014/50857-8 (INCT), 2021/01324-0 (FA scholarship)]; University of São Paulo under Grant [Programa Unificado de Bolsas - PUB 2021].