Preparation of Honey-Loaded Liposomes and Evaluation of Their Physicochemical and Antibacterial Properties.

Background: Honey is a natural wound-healing agent with antibacterial properties. It is applied to wounds in pure form or in conventional formulations; however, its application and efficacy may be challenging. Liposomes have been used as promising carriers for natural products. Therefore, honey-loaded liposomes were prepared and investigated as novel carriers for honey. Objectives: This study aimed to prepare honey-loaded liposomes using different honey concentrations and to characterize the formulations. Methods: Honey-loaded liposomes were prepared using the thin-film hydration method with egg lecithin and cholesterol at an 8:2 molar ratio and were hydrated with aqueous solutions containing 5% - 75% (w/v) honey. The mean particle size and zeta potential were measured by dynamic light scattering. Surface morphology was characterized by electron microscopy. Entrapment efficiency and the percentage of honey released were evaluated by quantifying honey polyphenols using the Folin-Ciocalteu assay as a marker of honey content. The minimum inhibitory concentration and minimum bactericidal concentration against Results: The liposomes had particle sizes of 94 - 282 nm, with the highest initial honey concentration (75%) yielding the largest particle size. Entrapment efficiencies were 22%-46%, with the 50% initial honey concentration showing the highest value. Increasing the initial honey concentration increased the honey content in the formulations. The zeta potential of plain liposomes was approximately -16 mV and shifted toward neutral values in honey-loaded liposomes (approximately -8 to -4 mV). Honey-loaded liposomes appeared as spherical particles, with some distorted spherical/angular particles. Honey release from liposomes showed a more extended pattern than that of honey solutions and followed Fickian diffusion kinetics from spheres for liposomes prepared with 5%-50% honey concentrations, whereas liposomes with a 75% initial honey concentration apparently favored first-order release kinetics. Biological assays showed enhanced antibacterial effects of liposomes of up to 3.5-fold and 7-fold against Conclusions: The present results demonstrate that liposomes can deliver honey compounds and that honey-loaded liposomes may be promising candidates for medical applications, such as wound treatment.