Characterization and drug delivery properties of OSA starch-based nanoparticles prepared in [C3OHmim]Ac-in-oil microemulsions system

In this work, an enhanced starch-dissolving room-temperature ionic liquid 1-hydroxypropyl -3-methylimidazolium acetate ([C3OHmim]Ac) was tailor-made to service as the polar phase in the formation of [C3OHmim]Ac/TX-100+1-butanol/cyclohexane (IL/O) microemulsion. Its superior solubility to starch was verified by the polarized-light microscope and turbidity test. Furthermore, pseudo-ternary phase diagram, conductivity measurement and dynamic light scattering (DLS) were used to analyze the phase behavior and microregion of IL/O microemulsion. Based on this, starch nanoparticles with a mean diameter of 86.69 nm were successfully prepared in this novel IL/O microemulsion with octenyl succinic anhydride (OSA) maize starch as the raw material and epichlorohydrin as a cross-linker through microemulsion crosslinking reaction. For starch nanoparticles, fourier transform infrared spectroscopy (FTIR) data demonstrated the formation of ester bonds and crosslinking reaction in starch molecules and X-Ray diffraction (XRD...