| OBJECTIVE:To observe magnetic fluid and SIS, which adsorb of magnetic particles in the alternating magnetic field the warming, and to discuss magnetic fluid and SIS (adsorb of magnetic particles) as hyperthermia medium in mouse colon cancer model, were effected of hyperthermia and safety.METHOD:In vitro, MF and SIS (adsorb of magnetic particles) were prepared, and heated for20min in an intermediate frequency AMF. By prussian blue staining observing, whether magnetic nanoparticles could be absorbed by colon cancer cells in mice (CT-26), HE dyeing observation that the SIS effected cell growth.Tumor-bearing mice were divided into six groups which received, respectively, no treatment (control); planted SIS alone; MF injection alone; AMF irradiation alone; and MF injection and hyperthermia generated by applying an AMF to the subaxillary region; planted SIS generated by applying an AMF to the subaxillary region. When the long size of tumor grew to lcm, MF injection alone group and MF injection and hyperthermia group, the tumor were injected magnetic liquid. Planted SIS alone group and planted SIS hyperthermia group were, planted SIS that absorbed7.8mg magnetic nanoparticles to packed tumour. Will MF injection and hyperthermia group and magnetic SIS heat hyperthermia group in alternating magnetic field were heated. A magnetic induction apparatus was used to apply an intermediate-frequency magnetic field to the subaxillary region. Adjust the magnetic field current strength cancer center will be heated to43°C temperature maintain, for60mins. Tumor-burdened mice, Observe the tumor growth and mice, their impact on survival time pathology. RESULT:The temperature of concentration of7.8mg/ml DMSA@y-Fe2O3and SIS (adsorped magnetic particles) were warmed rapidly,in the first10mins, the temperature was into platform later. Magnetic fliud was heated to80.2°C, and SIS adsorped magnetic particles was heated to68.7°C in alternating magnetic field that were frequency of40KHz, current for320A. Prussian blue staining showed that the magnetic nanoparticles were phagocytosed by the CT-26cells.Hematoxylin-eosin staining shew CT-26cells could grow on SIS.In vivo experiment the temperature reached approximately43°C rapidly at the tumors centers, and was kept at the same temperature by varying the current intensity in magnetic field. In contrast, rectal temperatures remained below36°C. Tumor growth was inhibited, and survival significantly prolonged in the hyperthermia group compared with control groups (P<0.05). After heating20days, in SIS heat treatment group, SIS came away from mouse skin pseudoaneurysm, and tumour ulcerated. Histopathological examination saw heat treatment of tumor cells were immediate apoptosis.CONCLUSION:SIS that absorbed magnetic nanoparticles was used as localized hyperthermia treatment of cancer in an AMF. It had a good heating ability. Preliminary studies in the dunning tumor model of colon cancer have demonstratrd the feasibility of MF in vivo.The temperature of hyperthermia can be controlled by changing the concentration of the AMF. MH led to a significant growth inhibition in this orthotopic model of the aggressive tumor variant. The survival time were extended. SIS (absorbed magnetic nanoparticles to implant heat treatment) were more effective than magnetic fliud hyperthermia on mice CT-26. |
