Gallium Protoporphyrin Liquid Crystalline Lipid Nanoparticles: A Third-Generation Photosensitizer against Pseudomonas aeruginosa Biofilms

• Published in: Pharmaceutics Vol. 14; no. 10; p. 2124
• Main Authors: Awad, Muhammed, Barnes, Timothy J., Thomas, Nicky, Joyce, Paul, Prestidge, Clive A.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 06.10.2022; MDPI
• Subjects: Antibiotics; antimicrobial; Antimicrobial agents; Bioavailability; biofilm; Biofilms; cubosomes; Dilution; Glycerol; Light; Lipids; liquid crystal nanoparticles; Nanoparticles; photodynamic therapy; United Kingdom > UK; Australia; United States > US
• ISSN: 1999-4923; 1999-4923
• DOI: 10.3390/pharmaceutics14102124

The looming antimicrobial resistance pandemic has encouraged the investigation of antimicrobial photodynamic therapy (aPDT) as a promising technology to combat recalcitrant bacterial infections caused by antibiotic resistant strains. Here, we report on the optimization and effective application of gallium protoporphyrin liquid crystalline lipid nanoparticles (GaPP-LCNP) as a photosensitizer for aPDT against the Gram-negative bacteria P. aeruginosa in both planktonic and biofilm modes of growth. LCNP significantly enhanced the performance of GaPP as photosensitizer by two-fold, which was correlated with higher antibacterial activity, reducing the viability of planktonic P. aeruginosa by 7 log10 using 0.8 µM GaPP-LCNP and a light dose of 17 J.cm−2. Importantly, GaPP-LCNP also reduced the viability of biofilms by 6 log10 at relatively low light dose of 34.2 J.cm−2 using only 3 µM GaPP-LCNP. The high antibiofilm activity of GaPP-LCNP at low GaPP-LCNP dose indicated the high efficiency and safety profile of GaPP-LCNP as a promising platform for photodynamic inactivation of recalcitrant infections.