Microenvironment-Responsive\nAntibacterial, Anti-Inflammatory,\nand Antioxidant Pickering Emulsion Stabilized by Curcumin-Loaded Tea\nPolyphenol Particles for Accelerating Infected Wound Healing

Multiphase Pickering emulsions, including two or more\nactive agents,\nare of great importance to effectively manage complicated wounds.\nHowever, current strategies based on Pickering emulsions are still\nunsatisfying since they involve only stabilization by inactive particles\nand encapsulation of the hydrophobic drugs in the oil phase. Herein,\nthyme essential oil (TEO) was encapsulated in the shell of functional\ntea polyphenol (TP)-curcumin (Cur) nanoparticles (TC NPs) to exemplarily\ndevelop a novel Pickering emulsion (TEO/TC PE). Hydrophobic Cur was\nloaded with hydrophilic TP to obtain TC NPs, and under homogenization,\nthese TC NPs adsorbed on the surface of TEO droplets to form a stable\ncore–shell structure. Owing to such an oil-in-water (O/W) structure,\nthe sequential release of the first Cur from pH-responsive disintegrated\nTC NPs and then the leaked TEO from the emulsion yielded synergetic\nfunctions of TEO/TC PE, leading to enhanced antibacterial, biofilm\nelimination, antioxidant, and anti-inflammatory activities. This injectable\nTEO/TC PE was applied to treat the infected full-thickness skin defects,\nand satisfactory wound healing effects were achieved with rapid angiogenesis,\ncollagen deposition, and skin regeneration. The present TEO/TC PE\nconstituted entirely of plant-sourced active products is biosafe and\nexpected to spearhead the future development of novel wound dressings.