Effects of preparation method on the release kinetics of curcumin-loaded composites

To explore the effects of preparation methods on the release kinetics of curcumin (Cur)-loaded sustained-release composites, three fabrication techniques—solvent casting, uniaxial electrospinning, and coaxial electrospinning—were employed to develop Cur-loaded composites using Cur as the model drug, soluble starch (St) and polyvinyl alcohol (PVA) as the matrices. The microstructure and chemical composition of three composite groups were characterized, and their functional properties were evaluated, including swelling capacity, degradation behavior, Cur loading capacity (LC), Cur encapsulation efficiency (EE), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Additionally, the in vitro Cur release behavior of the composites was analyzed, and release kinetics were fitted using mathematical models. Results indicated that the preparation methods had no significant impact on the chemical composition of the Cur-loaded composites. However, the nanofibers fabricated by the coaxial electrospinning technique exhibited a unique core-shell microstructure, which distinguished them from the cast films and uniaxial electrospun membranes. Compared with the other two groups, the coaxial membrane showed higher Cur LC and EE, a higher swelling ratio, a lower degradation rate, and a stronger DPPH radical scavenging ability. Kinetic fitting revealed that the Cur release profiles of all three composite groups conformed to the First-order model, but their release performances differed significantly. The coaxial electrospun membrane outperformed the cast film and uniaxial electrospun membrane, with a Cur cumulative release rate of 51.73 % at 96 h and retained significant potential for sustained release. In conclusion, the preparation method directly regulated the antioxidant activity and sustained-release behavior of Cur in the composites. This study provides theoretical basis and technical reference for the design and development of novel drug-loaded sustained-release composite materials.