Co‐axial electrospinning of liposomal propolis loaded gelatin‐zein fibers as a potential wound healing material

Abstract

In this study, propolis extract (PE) was first encapsulated in different liposomal formulations (65–370 nm) with high encapsulation efficiency (68%–93%). The liposomal PE was further embedded in a food‐grade gelatin‐zein core/shell fiber by using the co‐axial electrospinning method. Transmission electron and confocal laser scanning microscopy verified the structure of liposomes and their homogeneous dispersion in fibers. Scanning electron microscopy (SEM) images confirmed the smooth morphologies of core/shell liposomal fibers. The loading of PE in liposomal fibers improved both thermal (differential scanning calorimetry) and textural (elongation at break and tensile strength) properties, and the fibers loaded with more PE provided higher mucoadhesiveness. The PE‐loaded fiber showed higher antimicrobial activity against Staphylococcus aureus. The incorporation of liposomal PE in fiber enhanced the viability of human skin fibroblast (HFF‐1) cells. The adhesion of HFF‐1 cells on fiber was demonstrated by SEM, thus PE‐loaded liposomal fiber could provide an efficient platform for cell growth. The findings of this study proposed that propolis‐loaded liposomal hybrid fibers produced by the co‐axial method can be used as a potential wound healing material.

Propolis-loaded liposomes: characterization and evaluation of the in vitro bioaccessibility of phenolic compounds

“…Our previous study determined that PE loading into the liposomes prepared without surfactant was limited. The highest PE loading was achieved at 0.6 % (w/v), and the incorporation of Tween 80 (T80) enabled us to load PE at higher concentrations (≥ 2 %) [ 15 ]. Therefore, in this study, in addition to T80, we employed AMP in the liposome formulations.…”

“…Considering the hydrophobic properties of PE, it was expected to be more included in the bilayers than in the internal aqueous phase of the liposome. Therefore, higher loading of PE in liposomes would result in the formation of larger liposomal vesicles [ 12 , 13 , 15 ]. The reduced zeta potential values might also indicate that PE was associated with the surfaces.…”

“…Soy lecithin (Lipoid S75), Tween 80 (T80), ammonium phosphatide (AMP), and propolis extract (PE) were dissolved in ethanol. The mass ratio was decided based on preliminary tests and our previous study [ 15 ]. Our goal was to use the minimum surfactant concentration that would allow us to load the highest PE in the final liposome without precipitating.…”

“…To determine the encapsulation efficiency (EE), free PE was separated from the PE-loaded liposomes by centrifuging at 4000 g for 40 min at 4 °C using an Amicon membrane ultra-centrifugal filter (50 kDa) [ 15 ]. 1 mL of liposome was added to the upper section of the filter, and free PE was filtered to permeate (lower section), while the PE-loaded liposomes stayed in the retentate phase (upper section).…”

“…The propolis loading only ranged from 0.25 to 0.5 % (w/v) in the previous studies [ 12-14 ] related to propolis-loaded liposomes. In our previous study [ 15 ], the highest propolis loading in liposomes produced without the aid of any surfactant was 0.6 % (w/v); higher than this concentration resulted in the precipitation of propolis. In this study, we aimed to enhance the loading of propolis into liposomes at higher concentrations (2 and 4 %, w/v) with the use of two different surfactants.…”