Curcumin-loaded pickering emulsions based on soy protein isolate aggregates enhance diabetic wound healing

Wound healing in diabetic patients is more complex and prolonged in comparison to nondiabetic persons, and dealing with this problem has attracted considerable attention from researchers. According to its anti-inflammatory and anti-infective properties, Curcumin has a valued place in therapeutics, including wound healing. Still, its low stability and poor bioavailability are significant barriers to using its desirable properties. Hence, various biocompatible and biodegradable delivery systems have been developed to address this issue. In this study, Pickering emulsion (PE) prepared from soybean oil containing curcumin and modified SPI solution at 85 °C at pH 2.0 with 130 mM NaCl for different durations were used as a delivery system for curcumin. Changes in SPI properties were analyzed using fluorescence spectroscopy, Fourier transform infrared spectroscopy, and tensiometry methods. The prepared PEs were studied using microscopic techniques. Curcumin loading efficiency by PE was measured by UV–visible spectroscopy, and the impact of curcumin-loaded PE on wound healing was tested in diabetic rats. Spectroscopic studies and microscopy images revealed SPI amyloid-like aggregates suitable for stabilizing oil-in-water PEs. Tensiometry and creaming stability studies indicated that at least 6 h of heating (HSPI₆) is necessary for optimal stability. Curcumin encapsulation efficiency was 95.7 ± 2.1 %. Curcumin-loaded PE-HSPI₆ increased the healing rate of diabetic wounds in male Wistar rats by 1.46-fold. This study presents an approach for using biocompatible and biodegradable PEs to deliver hydrophobic compounds like curcumin for accelerating diabetic wound healing.