Chemotherapy is currently one of the most common methods of tumor treatment, but the drug resistance of tumor cells in the process greatly limits the effectiveness of this treatment strategy. In addition, the conventional methods of triggering drug release by pH and redox strategies cannot control the release process through external stimuli, so the development of this type of technology faces huge challenges. In recent years, the use of magnetic control methods to overcome tumor drug resistance and achieve safe, controllable and effective treatment of cancer has become one of the research hotspots in this field. This precise, non-invasive, and remote method can not only freely control the release time of nanomedicine, but also increase the amount of drug released, and it can also increase the mechanical killing of tumors within the effective range.
In response to the above problems, Wu Aiguo's research team at the Cixi Institute of Biomedical Engineering, affiliated to the Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, has developed a new and highly effective method for the treatment of cancer and has made some progress. The team successfully prepared ferrites with uniform particle size distribution, strong magnetic response, and good stability in the early stage: ZnxFe3-xO4 series of nanomaterials. By comparing the internal structure and magnetic moment of different nanoparticle materials with different zinc doping levels The changing trend of this type of material clarifies the internal relationship between the structure and magnetic properties of this type of material, and conducts an in-depth study of its magnetic resonance imaging mechanism (Chemistry of Materials. 2019, 31, 7255.). It provides a theoretical basis for the subsequent optimization of the performance of magnetic resonance contrast agents, and also lays a material basis for its subsequent use in biological therapy.
Based on the above results, the team recently used Zn0.2Fe2.8O4 nanoparticles with the best magnetic responsiveness in this series of ferrite magnetic materials to synthesize a nanocomposite drug, namely Zn0.2Fe2.8O4 magnetic nanoparticles and anticancer drugs. DOX is co-carried into polylactic acid-glycolic acid copolymer (PLGA) spheres, and the release of internal chemotherapeutic drugs is controlled by external magnetic force and generates magnetomechanical force to achieve the dual purpose of magnetic force and chemotherapy to kill tumor cells . In addition, based on the theoretical model, the trajectory and impact force generated by this series of ferrite magnetic nanomaterials under the action of different magnetic field strengths are calculated, and the law of the influence of the magnetic force on the biological organism is compared and the mechanism of tumor cell death is also explained. Explored. The magneto-mechanical force can not only destroy the cell membrane of tumor cells to cause necrosis, but also destroy the internal lysosomes to realize tumor cell apoptosis. This precise, non-invasive, and remote treatment provides a new way to overcome the drug resistance of tumor cells and enhance tumor killing, as well as new ideas for mechanical stimulation of other biological activities. This work was published in Nano Today 35 (2020) 100967 (DOI: 10.1016/j.nantod.2020.100967) with a paper entitled "Magnetically switchable mechano-chemotherapy for enhancing the death of tumour cells by overcoming drug-resistance".