Anti-MRSA malleable liposomes carrying chloramphenicol for ameliorating hair follicle targeting

Abstract

Ching-Yun Hsu,1,2,* Shih-Chun Yang,3,4,* Calvin T Sung,5 Yi-Han Weng,4 Jia-You Fang2,4,6,7 1Department of Nutrition and Health Sciences, 2Research Center for Food and Cosmetic Safety and Research Center for Chinese Herbal Medicine, Chang Gung University of Science and Technology, Kweishan, 3Department of Cosmetic Science, Providence University, Taichung, 4Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, Kweishan, Taiwan; 5School of Medicine, University of California, Riverside, CA, USA; 6Chinese Herbal Medicine Research Team, Healthy Aging Research Center, Chang Gung University, 7Department of Anesthesiology, Chang Gung Memorial Hospital, Kweishan, Taiwan *These authors contributed equally to this work Abstract: Pathogens usually invade hair follicles when skin infection occurs. The accumulated bacteria in follicles are difficult to eradicate. The present study aimed to assess the cutaneous and follicular delivery of chloramphenicol (Cm)-loaded liposomes and the antibacterial activity of these liposomes against methicillin-resistant Staphylococcus aureus (MRSA). Skin permeation was conducted by in vitro Franz diffusion cell. The anti-MRSA potential was checked using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), a well diffusion test, and intracellular MRSA killing. The classic, dimyristoylphosphatidylcholine (DMPC), and deoxycholic acid (DA) liposomes had a vesicle size of 98, 132, and 239 nm, respectively. The incorporation of DMPC or DA into the liposomes increased the bilayer fluidity. The malleable vesicles containing DMPC and DA showed increased follicular Cm uptake over the control solution by 1.5- and 2-fold, respectively. The MIC and MBC of DA liposomes loaded with Cm were 62.5 and 62.5–125 µg/mL, comparable to free Cm. An inhibition zone about 2-fold higher was achieved by DA liposomes as compared to the free control at a Cm dose of 0.5 mg/mL. DA liposomes also augmented antibacterial activity on keratinocyte-infected MRSA. The deformable liposomes had good biocompatibility against keratinocytes and neutrophils (viability >80%). In vivo administration demonstrated that DA liposomes caused negligible toxicity on the skin, based on physiological examination and histology. These data suggest the potential application of malleable liposomes for follicular targeting and the treatment of MRSA-infected dermatologic conditions. Keywords: chloramphenicol, malleable liposomes, deoxycholic acid, hair follicle, MRSA, antibacterial activity

Keywords

• chloramphenicol
• malleable liposomes
• deoxycholic acid
• hair follicle
• MRSA
• antibacterial activity