Iturin A with cyclic peptide and fatty acid chain isolated from Bacillus subtilis fermentation shows a variety of biological activities. Among them, the anticancer activity attracted much attention. However, the molecular mechanism of its inhibitory effect on hepatocellular carcinoma was still unclear. Thus its effect on hepatocellular carcinoma was tested in this research. It was found that iturin A could enter HepG2 cells immediately and cause reactive oxygen species burst, disrupt cell cycle and induce apoptosis, paraptosis and autophagy in vitro. The iturin A without fatty acid chain showed no antitumor activity. Amphiphilic is critical to the activity of iturin A. The anticancer activity of iturin A to hepatocellular carcinoma was also verified in mice models carrying xenograft tumors constructed by HepG2 cells. At a dosage of 3 mg/kg/day, iturin A significantly inhibited the further increase of the tumor weight by 58.55%, and reduced the expression of Ki67 in tumor. In the tumor treated with iturin A, lymphocyte infiltration was found, and the expressions of TGF-β1and PD-L1 were decreased, which indicated that the tumor immune microenvironment was improved. Besides, iturin A showed no significant harm on the health of mice except slight disturbance of liver function. These results suggested that iturin A had significant antitumor effect in vitro and vivo, and provide a basis for the application of iturin A as anticancer agent.

In order to investigate the biotribology behavior of a novel artificial joint pair composed of a carbon/carbon composite femoral head and an ultra-high molecular weight polyethylene (UHMWPE) acetabular cup, a hip joint simulator was employed to predict the clinical wear behavior with a constant load and a lubricant of newborn calf serum. The worn surface and the wear particles generated were analyzed by scanning electron microscopy and laser particle size analyzer. The results showed that the worn surface of UHMWPE had a ripple-like morphology with plentiful furrows. The wear particles generated had various morphologies with a size concentrated at about 15 μm.

2D-C/C composites with the dimension of Φ80mm×400mm were prepared rapidly by thermal gradient CVI within 104 hours. Their density reached 1.74g/m3and the density difference was less than 0.04g/cm3. The pyrocarbon microstructure changed from RL to RL+SL, and then to SL along radial direction. These changes were attributed mainly to the difference of gas concentration and temperature gradient at every micro-zone during chemical vapor infiltration. After heat-treatment at high temperature, the space among layers of pyrocarbon enlarged and residual thermal stress was freed, which could lead to cracks formed in matrix. The flexural property of composites decreased with increasing heat-treatment temperature and the fracture mode changed from the brittleness to pseudo-plastic. Carbon particulars between pyrocarbon laminas can increase the flexural strength by particular reinforcement.

Submicro-scaled graphite flakes with uniform distribution on the surface of carbon fiber were grown in situ by catalytic chemical vapor deposition with natural gas as feedstock. Morphology and structure parameter of graphite flakes were characterized by scanning electron microscope and Raman spectroscopy respectively. The results show that graphite flakes with assistance of iron hydroxide aqueous collosol had better shape, higher density and graphitization degree compared with specimen prepared with ferric chloride solution. The size in plane of as grown graphite flakes is in the range of 1-3 μm. Microcrystal domain size of graphite flakes is calculated about 5 nm according to ration of intensity of D band to G band in Raman spectra.

In this study, we prepared porous nano-hydroxyapatite/ polyamide 66 (n-HA/ PA66) porous scaffolds by injection molding method. The morphology, macrostructure and mechanical strength of the scaffolds were characterized. Osteoblasts (OBs) derived from cranial bone of SD rats were cultured and seeded on n-HA/ PA66 scaffolds. The OB/scaffold constructs were cultured for up to 18 days and the adhesion, proliferation and osteogenic activity of OBs were observed by scanning electron microscope and detected by alkaline phosphatase activity. The results showed that the porous n-HA/PA66 porous scaffolds are biocompatible and have no negative effects on the OBs in vitro. The scaffolds fulfill the basic requirements of bone tissue engineering scaffold, and have the potential application in orthopedic, reconstructive and maxillofacial surgery areas.