Jia-You Fang,1â 3 Wei-Ling Chou,4 Chwan-Fwu Lin,2,3,5 Calvin T Sung,6 Ahmed Alalaiwe,7 Shih-Chun Yang1,8 1Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, Kweishan, Taoyuan, Taiwan; 2Research Center for Food and Cosmetic Safety and Research Center for Chinese Herbal Medicine, Chang Gung University of Science and Technology, Kweishan, Taoyuan, Taiwan; 3Department of Anesthesiology, Chang Gung Memorial Hospital, Kweishan, Taoyuan, Taiwan; 4Department of Traditional Chinese Medicine, Chang Gung Memorial Hospital, Keelung, Taiwan; 5Department of Cosmetic Science, Chang Gung University of Science and Technology, Kweishan, Taoyuan, Taiwan; 6Department of Dermatology, University of California, Irvine, CA, USA; 7Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al Kharj, Saudi Arabia; 8Department of Cosmetic Science, Providence University, Taichung, TaiwanCorrespondence: Shih-Chun YangPharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, Kweishan, Taoyuan, TaiwanEmail phageyang@gmail.comBackground: The biofilm produced by Cutibacterium acnes is a major infection threat for skin and implanted catheters. Nanoparticles provide a new approach to eradicate biofilms. The present study evaluated the capability of cationic liposomes loaded with DNase I (DNS) and proteinase K (PK) to remove preformed C. acnes biofilms.Methods: DNS and PK were able to target and disassemble the biofilm by degrading extracellular polymer substances (EPS). Soyaethyl morpholinium ethosulfate (SME) was used to render a positive charge and enhance the antibacterial activity of the liposomes.Results: The cationic liposomes containing enzymes yielded monodisperse nanovesicles ranging between 95 and 150 nm. The entrapment efficiency of the enzymes in the liposomes achieved a value of 67â 83%. All liposomal formulations suppressed planktonic C. acnes growth at a minimum inhibitory concentration (MIC) equal to the free SME in the solution. The enzyme in the liposomal form inhibited biofilm growth much better than that in the free form, with the dual enzyme-loaded liposomes demonstrating the greatest inhibition of 54% based on a crystal violet assay. The biofilm-related virulence genes PA380 and PA1035 were downregulated by the combined enzymes in the liposomes but not the individual DNS or PK. Scanning electron microscopy (SEM) and confocal microscopy displayed reduced C. acnes aggregates and biofilm thickness by the liposomal system. The liposomes could penetrate through about 85% of the biofilm thickness. The in vitro pig skin permeation also showed a facile delivery of liposomes into the epidermis, deeper skin strata, and hair follicles. The liposomes exhibited potent activity to eliminate C. acnes colonization in mouse skin and catheters in vivo. The colony-forming units (CFUs) in the catheter treated with the liposomes were reduced by 2 logs compared to the untreated control.Conclusion: The data suggested a safe application of the enzyme-loaded cationic liposomes as antibacterial and antibiofilm agents.Keywords: liposomes, cationic surfactant, DNase I, proteinase K, Cutibacterium acnes, biofilm