Cationic liposome of hen egg white lysozyme for enhanced its stability, activity and accessibility in gastro-intestinal tract

Hen egg white lysozyme (HEWL) is a food-derived antimicrobial protein, exhibiting bacteriolytic activity against several bacteria including foodborne enteric pathogens. It has been approved for using in food, pharmacological and therapeutic applications. However, using HEWL through the ingestion is still a challenge due to its poor stability and low bioavailability in the gastro-intestinal tract (GIT). Herein, liposomes incorporating with dimethyl dioctadecyl ammonium bromide (DDAB) were fabricated to encapsulate HEWL (Lip_HEWL_DDAB) for oral delivery. Lip_HEWL_DDAB was spherical with an average diameter of 162.7 ± 1.6 nm and zeta potential of 37.1 ± 4.3 mV. The Lip_HEWL_DDAB had high entrapment efficiency of 80% and 11% loading efficiency of HEWL. The formulated Lip_HEWL_DDAB were highly physicochemical stable in both simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) and capable of enhancing the intestinal absorption via their mucoadhesive property while retaining antimicrobial activity against enteric bacteria. HEWL was released from Lip_HEWL_DDAB via diffusion mechanism at higher extent than those without the DDAB. Additionally, the prepared Lip_HEWL_DDAB was non-toxic at below 6.25 μg/ml to intestinal cells and was able to deliver HEWL across an in vitro intestinal epithelium model, resulting in enhanced anti-microbial/anti-inflammatory activities, compared to their free- and unmodified-liposomal forms. Together, our modified cationic liposome is a new and promising strategy for improving oral delivery of HEWL with enhanced nutraceutical functions.