Safety and delivery efficiency of a photodynamic treatment of the lungs using indocyanine green and extracorporeal near infrared illumination

Author(s)

Kassab, Giulia ; Cheburkanov, Vsevolod ; Willis, Jace ; Moule, Madeleine G. ; Kurachi, Cristina ; Yakovlev, Vladislav ; Cirillo, Jeffrey D. ; Bagnato, Vanderlei S.

• Document type: Journal article
• Source: Journal of Biophotonics; v. 13, n. 10, p. 13-pg., 2020-08-12.

Abstract

Photodynamic inactivation (PDI) is a promising alternative for combating infections caused by antimicrobial resistant bacteria. Pneumonias are among the most worrisome infections because of their high-mortality rate. Previous studies have demonstrated the feasibility of using PDI with extracorporeal light to treat pneumonia. In this study, we analyzed key parameters for the viability of this treatment, including the selectivity of the photodynamic response for pathogens over host cells. Our results showed that PDI can induce killing ofStaphylococcus aureus(of up to 4.18 log for the strain Xen29 and 3.62 log for Xen36) under conditions where little or no toxicity for host cells is observed. We validated pulmonary delivery of the photosensitizer and light in mice, using photobleaching as an indicator, and demonstrated preservation of healthy tissues as evidence of the safety of the protocol. Overall, PDI displays low toxicity on host tissues, making it a promising tool for treatment of pneumonias caused byS. aureusand other important pathogens. (AU)

• FAPESP's process: 18/18188-0 - Photodynamic inactivation of Bacterial Pneumonia with nebulization of the photosensitizer and extracorporeal illumination
• Grantee: Giulia Kassab
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 13/07276-1 - CEPOF - Optics and Photonic Research Center
• Grantee: Vanderlei Salvador Bagnato
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC