Functionalization Of Fe₃O₄Filled Magnetic Carbon Nanotubes And Biomedical Applications

The worldwide increase of incidence of cancer should be carefully treated. The effect of commonly used medicine is limited due to the lack of target specificity and its potential side effects to the healthy tissues. Thus it is necessary to improve the targeting specificity of conventional medicine and their therapeutic effect. Moreover, it will be more helpful to understand the treatment effect timely and accurately if biological labeling of tumor tissue could be achieved. In this work, a multi-functional nano drug carrier is developed by covering the magnetic carbon nanotubes with quantum dots and transferrin. The targeting cure and imaging trace of Hela cells are achieved via the load/unload of doxorubicin (DOX) by the developed nano drug carrier.Firstly, carbon nanotubes are filled with Fe3+ions by controlling the pressure difference of internal/external surfaces of carbon nanotubes by controlling the vacuum. Magnetic carbon nanotubes are thus obtained after calcination. The methodology of filling magnetic nanoparticles inside the tube, not only is helpful to control the size of magnetic nanoparticles and avoids the de-immoblization of nanoparticle encountered in the outer-coating protocol, but also offers a larger external surface area to achieve further functionalization and drug-loading. In addition, the positively charged QDs are immoblized on the surface of magnetic carbon nanotubes via electrostatic attraction, and thereafter, transferrin are strongly bonded onto QDs by EDC/NHS coupling reaction. The obtained composites are characterized by DLS, Zeta potential, TEM, XRD, UV-Vis, FL and VSM. The results indicate that the obtained multi-functional composites possess excellent solubility and biocompatibility. It is characterized by the coupling of magnetic targeting and biological targeting, and the ability of tracing imaging of cells.The applications of the multi-functional composites in nano drug carrier are investigated. DOX could be loaded onto the magnetic carbon nanotubes via π-π stacking. Excellent treatment effect of the drug carrier to Hela cells are validated by MTT assay. The drug-loading efficiency is110%in PBS (pH=8.5). Controlled and slow release behaviors of the loaded drug are demonstrated under a simulated internal environment of tumor cells. The treatment effect is improved by local enrichment and controlled release of loaded drug under an external magnetic field.