Modified chitosan micelles improving physical stability, sustained release, and antibacterial activity of fir...

To meet consumer demand for the application of natural ingredients such as essential oils in food systems, this study developed a chitosan-g-poly(lactic acid) (CS-g-PLA) micellar system for fir essential oil (FEO) delivery. The research focused on investigating the regulatory effects of PLA side-chain parameters on micellar properties. Results demonstrated that increasing parameters enhanced hydrophobic interactions, forming compact micelles with a minimal particle size (229.7 nm) and critical micelle concentration (0.012 mg/mL). The hydrophobic core enabled efficient FEO loading (30.99%) with stable sustained release. FEO@CS-g-PLA micelles also showed broad-spectrum antimicrobial activity by disrupting cell membranes. Molecular dynamics simulations visualized the self-assembly of CS-g-PLA and the FEO loading process, providing theoretical support for experimental observations. In summary, this work offers microscopic insights into the micellization of modified CS-g-PLA and FEO loading mechanisms, providing a feasible strategy for applying essential oils in food preservation.