Glycine-functionalized Fe3O4@TiO2:Er3+,Yb3+ nanocarrier for microwave-triggered controllable drug release and study on mechanism of loading/release process using microcalorimetry

Objectives: The current study aimed at developing microwave-triggered controlled-release drug delivery systems using glycine-modified Fe3O4@TiO2: Er3+,Yb3+ multifunctional core-shell nanoparticles. We also studied the drug loading and release mechanisms by means of microcalorinnetry. Methods: We used hydrothermal method to prepare glycine-functionalized Fe3O4@TiO2:Er3+,Yb3+ multifunctional nanoparticles. The controlled release of the Fe304@Ti02:Er3+,Yb3+-glycine-VP16 triggered by microwave was determined with ultraviolet-visible spectroscopic analysis. We studied the cytotoxicity of the nanocarrier by MU assay. Results: The thermodynamic parameter values (Delta H = -17.46 kJ mol(-1), Delta S = -365.20 kJ mol(-1)) showed that the main interaction between the carrier and drug molecules is hydrogen bonding. The molar enthalpy (Delta H) of the drug-release process was 72.01 kJ mol(-1), which indicates an endothermic process. This suggests that drug release can be controlled by microwave heating. The release profile can be controlled by the duration and number of cycles of microwave application. The particles also exhibit good magnetization and upconversion luminescence properties, which will allow simultaneous targeting and monitoring of the loaded drug. Conclusion: The modification of glycine and the introduction of absorbing material not only increased the load properties of the composite materials but also realized the microwave-stimulated anticancer drug controlled release.