The Process Of Hepatoma Cells Absorbing Inorganic Nanoparticles And The Change Of Cells

It had been reported that inorganic crystal nanoparticles (ICN) could inhibit the proliferation of cancer cells. The purpose of this study is to confirm that ICN could be absorbed into cytoplasm, exam the approach and process of absorption, and investigate change of nanoparticles and cancer cell.Bel-7402 cells, a hepatoma cell line, were selected to incubation with HAP nanoparticles for 8 hours. Then many particles in shape similar to HAP were found in cytoplasm under Transmission Electronic Microscope (TEM ) . By energy dispersing spectrum (EDS) analysis, the intracellular particles contained calcium (Ca) and phosphorus (P) . The classic rings of HAP crystal appeared in the electronic diffraction (ED) pictures of these particles. So these particles were confirmed as HAP nanoparticles. Thus, it was concluded that HAP nanoparticles coulc be absorbed by cancer cells as the crystal particles.To investigate the approach of nanoparticles absorption, the Bel-7402 cells were treated before incubation with HAP nanoparticles. After incubation with the Bel-7402 cells treated by DMSO, most of HAP nanoparticles appeared in the nuclear area. This illustrated that nuclear envelope could block off free diffusion of nanoparticles. After treated by Cytochalasin B for 1 hour, only few nanoparticles could be absorbed into cytoplasm. In treated by Cytochalasin B for 12 hour group, no HAP nanoparticle was found in cells. This indicated cancer cells phagocytosised nanoparticles by microfiber assistance. After treated by Nimodipine, HAP nanoparticles were absorbed into cytoplasma as before. So calcium channel block had nothing to do with the absorption process. Another, the fact that intracellular HAP nanoparticles were found after incubation with Bel-7402 cells for 0.5 hour, indicated the phagocytosis process finished fast.After high temperature and press disinfection, no change in the shape and size of ICN stated that this disinfection way was fitted to nanoparticles. When mixed with medium, the ICN dispersed but about 50% reducing in size. However, the ICN size did not change after low speed centrifugation. So those nanoparitcles in this study still remained dispersing and nano-size, and the results did not affected by disinfection,mix in medium and centrifugation.After phagocytosised into cytoplasm, TiC>2 could not be decompounded in cancer cells. On the contrary, HAP nanoparticles could be digested in cells so that they should be the ideal biomaterials.Endocytosised ICN, the Bel-7402 cells were examined under TEM: disruption of cytoplasm around nanoparticles, expansion of endoplasmic reticulums, swelling and collapse of most of mitochondrias, disorder of mitochondrias crista, expansion of nuclear space, shrinkage of nuclear envelope, pycnosis of karyotin. Even apoptosis body was found. By TUNEL technology, more brown signals were detected in the HAP nanoparticle group than the control group. After incubation with HAP nanoparticles, the DNA of Bel-7402 cells appeared 'ladder'. So it could be concluded that HAP nanoparticles induced apoptosis of Bel-7402 cells.