Temperature‐Responsive Hydroxypropyl Cellulose Microcapsules Modulated by Hyaluronic Acid for Controlled Release of Carvacrol and Dementholized Peppermint Oil

Commonly used temperature‐responsive delivery systems still exhibit intrinsic limitations in the precise tuning of the release temperature and environmental adaptability. Meanwhile, Increasing concerns over microplastic pollution have driven the development of biodegradable microcapsules as alternatives to conventional polymeric delivery systems. Herein, hyaluronic acid (HA) is introduced to achieve temperature‐responsive release in hydroxypropyl cellulose (HPC)‐based microcapsules. Through competitive hydrogen bonding, HA shifts the phase transition temperature (Tp) of methacrylic anhydride‐modified hydroxypropyl cellulose (HPC‐MA). After the incorporation of 2 wt% HA, its Tp decreased from 34.70°C to 30.69°C. Carvacrol (CV) and dementholized peppermint oil (DPO) were co‐encapsulated via free‐radical polymerization, endowing the CV‐DPO@HPC‐MA/HA microcapsules with antioxidant functionality. The obtained microcapsules exhibited a mean particle size of 1.3 μm, with an encapsulation efficiency (EE) of 88.0%. At 32°C, the final cumulative release of HA‐modified microcapsules was 20.58% higher than that of unmodified microcapsules. At a concentration of 10 mg/mL, the microcapsules achieved 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and 2,2′‐azino‐bis (3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) radical scavenging rates of 85.49% and 86.85%, respectively. Besides, both types of microcapsules demonstrated excellent biocompatibility and low cytotoxicity. This work provides a simple strategy to adjust the release temperature of microcapsules and offers a promising design route for stimuli‐responsive microcapsule systems.