Photomagnetic Control of Nanoparticles With Radical Pair System: A Promising New Area of Liposomal Drug-Delivery System

A large number of techniques have been developed to investigate magnetic nanoparticles for biomedical engineering applications to drug-delivery systems. In this paper, we carried out research into a new drug-release technology using liposomal nanoparticles equipped with magnetic controls. Exposures to magnetic fields were carried out using a permanent magnet (0.25 T) or an air-cored coil system (40 mT). Under exposure to the static field, anticancer flutamide (FM) in the liposomal membrane was excited by an emission wavelength of 325 nm. To compare the drug-release potentials with magnetic field effects on the behavior of FM in the model membranes, we measured the spectral changes with absorbance at 314, 260, and 370 nm after the excitation. Judging from the overall result of our liposomes prepared in this paper, up to 20 min after the excitation, the gradual increases in the drug-releases were relatively consistent with an $S-T$ level intersystem crossing for a radical pair mechanism in equilibrium. Concerning the releases with magnetic field effects, the release rates obtained using a homogenous field of 0.25 T were more extensive on the order of 67%-75%, than those obtained at 0 T. Our system may provide the best possible balance between clinical performance and low invasivity. We believe the idea that magnetic fields are extremely suitable for the gentle control of chemical reactions.