In vivo treatment of Propionibacterium acnes infection with liposomal lauric acids

Abstract

Propionibacterium acnes (P. acnes) is a Gram-positive bacterium strongly associated with acne infection. While many antimicrobial agents have been used in clinic to treat acne infection by targeting P. acnes, these existing anti-acne agents usually produce considerable side effects. Herein, the development and evaluation of liposomal lauric acids (LipoLA) is reported as a new, effective and safe therapeutic agent for the treatment of acne infection. By incorporating lauric acids into the lipid bilayer of liposomes, it is observed that the resulting LipoLA readily fuse with bacterial membranes, causing effective killing of P. acnes by disrupting bacterial membrane structures. Using a mouse ear model, we demonstrated that the bactericidal property of LipoLA against P. acne is well preserved at physiological conditions. Topically applying LipoLA in a gel form onto the infectious sites leads to eradication of P. acnes bacteria in vivo. Further skin toxicity studies show that LipoLA does not induce acute toxicity to normal mouse skin, while benzoyl peroxide and salicylic acid, the two most popular over-the-counter acne medications, generate moderate to severe skin irritation within 24 h. These results suggest that LipoLA hold a high therapeutic potential for the treatment of acne infection and other P. acnes related diseases.

Keywords: Propionibacterium acnes; antimicrobial delivery; bacterial infection; free fatty acid; nanoparticle.