PVA/gelatin hydrogel loaded with propolis for the treatment of myocardial infarction

Recently, propolis has shown potential cardioprotective effects against myocardial infarction. However, challenges in its clinical application have arisen, primarily due to concerns regarding dosage and potential adverse effects. To address this, we suggest integrating propolis into polyvinyl alcohol (PVA)/gelatin hydrogel to regulate the localized release of propolis at infarcted sites. PVA/gelatin hydrogels with varying propolis concentrations (3%, 7%, and 10%) were fabricated using a freeze-thawing method, and we characterized their microstructure, mechanical properties, and swelling behavior. Additionally, we examined propolis release profiles and assessed the cytotoxicity of the hydrogels. The presence of propolis in the PVA/gelatin hydrogel interfered with PVA and gelatin chains through intermolecular hydrogen bonding, consequently restricting chain movement and enhancing mechanical strength with increasing propolis concentration. The swelling ratio decreased by at least 40% upon the addition of propolis to the PVA/gelatin hydrogel. The PVA/gelatin hydrogels with different concentrations of propolis exhibited sustained release of propolis characterized by a burst release in the initial hour followed by a release at a constant rate up to 120 min, 240 min, and over 360 min for 3%, 7%, and 10% propolis, respectively. Moreover, the cytotoxicity test of the hydrogels' degradation products against HEK 293 cells revealed cell viability within the range of 80-90%, indicating that the hydrogels were non-toxic and safe for cell growth. The incorporation of propolis into PVA/gelatin hydrogels not only allows for controlled localized release but also presents a promising therapeutic approach for myocardial infarction.