Dai Honglian

Selective anti-hepatoma treated with titanium oxide nanoparticlesin vitro

Effects of titanium oxide (TiO2) nanoparticles on Bel-7402 human hepatoma hepatoma cells and L-02 human hepatocytes at different times were observed. Using cell culture, cell growth curves of Bel-7402 cells and L-02 cells treated with TiO2 nanoparticles were examined by MTT assay, and the cellular ultrastructure was observed by an analytical transmission electron microscope (ATEM). It is found that OD value of Bel-7402 cell treated with TiO2 nanoparticles for 48–144h is obviously lower than that of control group (p<0.01). However the growth curve of L-02 cells is almost not affected by TiO2 nanoparticles. ATEM and energy dispersive X-ray (EDX) analyses show that there are obvious vacuoles increased heterolysosome, and particles with high electron density which are confirmed to be TiO2 nanoparticles in Bel-7402 cytoplasm. More interestingly, it is alse found that TiO2 nanoparticle obviously inhibits the proliferation of hepatoma cells by altering lysosome activity and destroying cytoplasm structure. The inhibition on proliferation of hepatocytes by TiO2 nanoparticles is much slighter. The results demonstrate that TiO2 nanoparticle has different killing effects on cancer cell and normal cell.

Cytotoxinic mechanism of hydroxyapatite nanoparticles on human hepatoma cell lines

Stable and single-dispersed HAP nanoparticles were synthesized with chemical method assisted by ultrasonic treatment. HAP nanoparticles were surveyed by AFM and Zataplus. The effect on the Bel-7402 human hepatoma cell lines treated with HAP nanoparticles was investigated by the MTT methods and observation of morphology, and the mechanism was studied in changes of cell cycle and ultrastructure. The result shows that inhibition of HAP nanoparticles on the Bel-7402 human hepatoma cell lines is obviously in vitro. HAP nanoparticles the entered cancer cytoplasm, and cell proliferation is stopped at G1 phase of cell cycle, thus, cancer cells die directly.

The transformation of calcium phosphate bioceramicsin vivo

To study the transformation process of calcium phosphate bioceramic in vivo, biodegradable porous β-tricalcium phosphate ceramics (β-TCP) were used in this experiment. The materials (ø5×8mm) were implanted in the tibia of rabbits. The β-TCP ceramics with bone tissue were retrieved, and treated for histology, and then observed by using a scanning electron microscope (SEM) and an electron probe X-ray microanalyzer (EMPA) every month. The results show that β-TCP ceramics bond to bone directly, new bones are forming and maturing with materials continuous degrading, and the materials are nearly replaced by the formed bone finally. Parts of the materials were degraded, absorpted and recrystallized, the others dispersped on the cancellous bone and the Haversian lamella with an irregular arrangement incorporating in bone formation directly by remodeling structure.

Biological evaluation of α-TCP/TTCP composite bone cement

Abstractα-tricalcium phosphate (α-TCP)/tetracalcium phosphate (TTCP) composite bone cement had good hydration characteristic. In our system, α-TCP/TTCP powder mixture was mixed with water at a powder/liquid (P/L) ratio of 1.50g·mL−1. The setting time could be adjusted, the maximum compressive strength was 45.36MPa, and the hydration product was hydroxyapatite (HAP). In vitro biological simulated experiments indicate that α-TCP/TTCP bone cement has α certain dissolubility. The hardened product is mainly HAP after soaking in simulated body fluid (SBF) for 10 weeks. The results of in vitro test and animal experiments and SEM analyses show that no local or general toxicity response, no muscle stimulation, no haemolysis, no cruor, no inflammatory reaction and no exclusion response are caused by α-TCP/TTCP cement, which can be contributed to bone tissue spreading and impinging. α-TCP/TTCP cement hydrated and hardened continually in vivo. The materials fused with host bone together with implanting time prolonging. Therefore, it is believed that α-TCP/TTCP composite bone cement has a high biocompatibility and bioactivity, a certain biodegradation and good osteogenesis as well.

Effects of Antihepatocarcinoma with Apatite Nanoparticles in vivo

The inhibition effect of hydroxyapatite (HAP) nanoparticles on hepatocarcinoma was investigated in vivo. The human hepatocarcinoma cell line Bel-7402 was transplanted subcutaneously into nude mice. Hydroxyapatite nanoparticles suspension at a dose of 0.2 mL was injected into the transplanted tumors every day for 2 weeks, and saline was used as control. The efficacy of hydroxyapatite nanoparticles on this carcinoma was surveyed and morphological changes of tissue and cells were observed by light microscopy and transmission electron microscopy (TEM). Experimental results show that hydroxyapatite nanoparticles have a visible destructive effect on the structures of hepatocarcinoma cells and tissue. The inhibition rates of tumor growth were 77.21% and 51.32% after intra-tumor injection of hydroxyapatite nanoparticles for 1 week and 2 weeks, respectively. Compared with the control group, hydroxyapatite nanoparticles can also prolong the survival time of the nude mice bearing this cancer significantly. This indicates that hydroxyapatite nanoparticles have the therapeutic potential on hepatoma in vivo.

Preparation of hydroxyapatite fibers by the homogeneous precipitation method

This paper discussed the preparing process of hydroxyapatite fibers which were widely used as reinformcement for biomedical materials by homogeneous precipitation method. The needle-like hydroxyapatite crystals were synthesized in an aqueous system. They were transferred from precursors-dicalcium phosphate anhydrate and octacalcium phosphate crystals. The reaction conditions were well controlled in order to obtain crystals in given morphology. The products were characterized by X-ray powder diffractometry (XRD), scanning electron microscopy (SEM) and infrared spectroscopy(IR). They were verified to be hydroxyapatite crystals with needle-like in shape.

Bone Formation Process of β-TCP Ceramics with Tetracycline Tracing

To study the new bone formation in the bone defect area after implantation, the tetracycline tracing method was used. The results show that new bone formed in 1 month, and the formation rate of new bone was very high (8. 164 μm/day), considerably faster than that of control groups (3.219 μm/day). The new bone grew up quickly and β_TCP particles were surrounded by double fluorescence bands which became more obvious. The new bone formation rate was maximal at 2 months, and then gradually reduced. The rate was steady at 4 months, and then reduced to resembling as the normal physiologic metabolism of bone, which indicated the implanted materials were completely replaced by bone. Calcium phosphate materials had the ability of osteoconduction.