A thesis submitted to the University of Bedfordshire in partial fulfilment of the requirements for the degree of Doctor of PhilosophyCancer treatment has become one of the top priorities in health. Great efforts have been devoted to the diagnosis and therapy of cancers. Culturing cells with drugs is a common method used to investigate cancer therapy in experiments. However, this method has limitations in cancer treatment because of the lack of capabilities of handling cells, targeting specific cells and measuring the nanoscale changes in cell structures. Magnetic nanoparticles (MNPs) and magnetic force microscopes (MFMs) have been used to study biological samples due to their advantages in tracing, manipulating and measuring, which has motivated to research the method for implanting MNPs into cancer cells, to target the cancer cells and to measure their changes during the treatment. Research reported in this thesis focuses on magnetic force imaging and handling of targeted cancer cells on the nanoscale for possible new cancer therapies.
A new differential MFM imaging method and a new compensation MFM imaging method were developed in this research to improve the MFM imaging quality. The former reverses the magnetized direction of probe from upward to downward and the latter scans the samples with three scanning directions of 0°, 45° and 90°. With these methods, the obtained MFM images achieve a high resolution, SNR, image contrast and accuracy.
A pair of innovative MNPs picking up method and MNPs releasing method were developed in this research to achieve flexible MNPs picking up and releasing. The picking up method handles the magnetic tip following a helical structure as the capture path when approaching to the target MNPs. The MNPs releasing method uses a biaxiably-oriented polypropylene (BOPP) film together with a magnet allowing MNPs to separate from the MFM tip surface. With these methods, the target MNPs can be picked up by the MFM tip and released from the tip surface successfully.
This research discovered, for the first time in the world to the author knowledge, the differences in morphological features (height, length, width and roughness) and mechanical properties (adhesive force and Young‟s modulus) between multinuclear and mononuclear colon cancer cells after treating the cells with fullerenol. This discovery provides guidance to the selection of cells for target treatment. The results indicate that the mononuclear SW480 cells are more sensitive to fullerenol than the multinuclear SW480 cells and the multinuclear SW480 cells exhibit a stronger drug-resistance than the mononuclear SW480 cells.
A new MNPs implantation method was developed in this research, which enables the FITC-MNPs functioned tip to insert into cells so that MNPs are implanted into the target cells. Fluorescence microscope images show that the FITC-MNPs are released into the cells successfully. Cells being treated with MNPs (Cell-MNPs) manipulation III
methods are explored by magnet and controllable electromagnets to manipulate the target cancer cells. The results show that the cell-MNPs have magnetic force manipulated capability and they can be manipulated to have the leftward, rightward, upward and downward flexibilities
