Microenvironment-Responsive Antibacterial, Anti-Inflammatory, and Antioxidant Pickering Emulsion Stabilized by Curcumin-Loaded Tea Polyphenol Particles for Accelerating Infected Wound Healing

Multiphase Pickering emulsions, including two or more active agents, are of great importance to effectively manage complicated wounds. However, current strategies based on Pickering emulsions are still unsatisfying since they involve only stabilization by inactive particles and encapsulation of the hydrophobic drugs in the oil phase. Herein, thyme essential oil (TEO) was encapsulated in the shell of functional tea polyphenol (TP)-curcumin (Cur) nanoparticles (TC NPs) to exemplarily develop a novel Pickering emulsion (TEO/TC PE). Hydrophobic Cur was loaded with hydrophilic TP to obtain TC NPs, and under homogenization, these TC NPs adsorbed on the surface of TEO droplets to form a stable core-shell structure. Owing to such an oil-in-water (O/W) structure, the sequential release of the first Cur from pH-responsive disintegrated TC NPs and then the leaked TEO from the emulsion yielded synergetic functions of TEO/TC PE, leading to enhanced antibacterial, biofilm elimination, antioxidant, and anti-inflammatory activities. This injectable TEO/TC PE was applied to treat the infected full-thickness skin defects, and satisfactory wound healing effects were achieved with rapid angiogenesis, collagen deposition, and skin regeneration. The present TEO/TC PE constituted entirely of plant-sourced active products is biosafe and expected to spearhead the future development of novel wound dressings.