Effects of essential oil on the properties of egg white/polyacrylamide (EW/PAAm) Pickering emulsion hydrogels (PEHs) via UV crosslinking

Abstract Currently, several researches have demonstrated that hydrogels are useful for wound healing in a variety of approaches. Herein, Pickering oil-in-water (o/w) emulsion hydrogels were rapidly produced by free radical photopolymerization (UV crosslinking). Egg white (EW) polymer and acrylamide monomer were used as water phase, whereas lavender essential oil was used as oil phase. The bio-based surfactant β-cyclodextrin was used to stabilize emulsion hydrogels. The introduction of lavender essential oil (LEO) in specific amounts in total emulsion (10 – 50% v/v) was performed. The functional groups in the hydrogels were confirmed by the attenuated total reflectance-Fourier transform ınfrared spectroscopy (ATR-FT-IR). The hydrogels had a swelling ratio of more than 200% and contact angle values of below 70°. The max compression stress of the hydrogels with 20% LEO concentration was 354.98 kPa. The morphology and mechanical characteristics of Pickering hydrogels may be changed by adjusting the increment of LEO concentration in emulsions. Increasing the oil concentration causes droplet diameters to be increased and Young’s modulus to be decreased. The hydrogels with LEO concentration of 40–50% showed antibacterial activity against Escherichia coli ( E. coli) and Staphylococcus aureus ( S. aureus ) with 9–12 mm zone inhibition. It was observed that the hydrodegradation phenomena increased with the increment of the lavender oil amount in the total emulsion and reached the highest 80.1% value for 28-day period. In accordance with the findings, the produced hydrogels have the potential to be used as wound dressings in wound healing applications. Graphical abstract