A green approach to the development of novel antibacterial cinnamon oil loaded-PVA/egg white foams via Pickering emulsions

Abstract

Cinnamon essential oil (CEO) has a low water solubility as a bioactive antibacterial agent with a good fragrance. Pickering emulsion template approach was presented for producing the wound dressing to enhance CEO loading in water-based polymer foams. In this scope, beta- cyclodextrin/cinnamon oil (beta-CD/CEO) inclusion complexes have been utilized as an emulsion stabilizer, whereas CEO and Polyvinyl alcohol/egg white (PVA/EW) polymer blends have been used as an internal and outer phase, respectively. The amounts of the beta-CD/CEO inclusion complexes were introduced into the PVA/EW foams at four different ratios (1.5, 3, 4.5, and 6) and their microstructural, optic, physical, swelling, hydrolytic degradation, and hydrophilicity properties were studied. SEM micrographs showed all PVA/EW/CEO foams open and close cell morphologies, while the stereo-microscope showed foams containing in the ratio of beta-CD/CEO 1: 6 have a porous surface without shrinkage on its surface. The existence of beta-CD/CEO inclusion complexes and physical interaction between polymer matrixes and the inclusion complexes confirmed by FT-IR spectroscopy. Moreover, the obtained foams have ideal hydrophilicity compatible with the skin with contact angle values ranging from 62.5 & DEG; & PLUSMN; 3.1 & DEG; to 70 & DEG; & PLUSMN; 3.5 & DEG;. Hydrolytic degradation of the foams decreased as the amount of CEO increased, and the values of more than 80% was seen in the foams at the end of 28 days. Even if CEO volatilized during the process, CEO-loaded PVA/EW foams indicated good antibacterial activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa bacteria with 10-20 mm zone inhibition values. Consequently, the produced PVA/EW/CEO polymer foams with Pickering emulsion approach demonstrated promising results for wound dressings.