A novel biomimetic micro/nano hierarchical interface of titanium enhances adhesion, proliferation and osteogenic differentiation of bone marrow mesenchymal cells / 口腔疾病防治

Objective @#To design a novel biomimetic micro/nano hierarchical interface on endosseous titanium implants and investigate its effect on the biological activity of bone marrow mesenchymal cells.@*Methods@#Electrochemical anodization and spark plasma sintering were used to modify smooth titanium (untreated Ti group) with a microporous trabecular bone-like architecture (micro-Ti group) and TiO2 nanotube architecture (nano-TiO2 group). Additionally, electrochemical anodization was employed to prepare TiO2 nanotubes on microporous trabecular bone-like architectures, which formed a novel biomimetic hierarchical interface (micro/nano-TiO2 group). Four groups of titanium samples were characterized by field emission scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle (CA). Bone marrow mesenchymal cells (BMMCs) were seeded on four groups of titanium samples. Scanning electron microscopy (SEM) was employed to observe cell morphology. Cell proliferation was determined by MTT assay. The expression of focal adhesion proteins (F-actin; vinculin; osteocalcin, OCN; osteopontin, OPN) were observed under a confocal laser scanning microscope (CLSM). The mRNA expression levels of osteogenic factors (runt-related transcription factor 2, RUNX2; osteocalcin, OCN; osteopontin, OPN; collagen I, COL I) were assessed by qRT-PCR.@*Results@# The micro/nano- TiO2 group featured a hydrophilic surface (CA=9° ± 2.1°). The results of the MTT assay indicated that the relative cell proliferation rates for the nano- TiO2 and micro/nano-TiO2 samples were significantly increased compared with those for the untreated-Ti and micro-Ti samples (P＜0.001) after 5-9 days. The ALP results indicated that the micro/nano-TiO2 sample gained the highest value at 14 days. After 72 h of incubation, the expression of osteocalcin (OCN) and osteopontin (OPN) on micro/nano-TiO2 was the strongest. After 24 h incubation, the expression of F-actin on micro/nano-TiO2 was the strongest. In comparison with untreated-Ti and micro-Ti samples,the mRNA expression levels of all the osteogenic factors (runt-related transcription factor 2, RUNX2; osteocalcin, OCN; osteopontin, OPN; Collagen I, COL I) were markedly increased on the nano-TiO2 and micro/nano-TiO2 samples, the mRNA expression levels of collagen I (COL I) were significantly different between the nano-TiO2 and micro/nano-TiO2 samples versus the untreated-Ti and micro-Ti samples (P＜0.001). @* Conclusion@#The novel biomimetic micro/nano hierarchical interface has a positive effect on cell attachment, viability and osteogenic differentiation of bone marrow mesenchymal cells.

Effects of three kinds of nanoparticles on proliferation and apoptosis of esophageal squamous carcinoma cells / 中国药理学通报

Aim TostudytheeffectsofCuO,ZnOand TiO2 nanoparticles on the viability and metastatic po-tential of EC-9706 and EC-109 esophageal squamous carcinomacelllineinvitro.Methods Characteristics of CuO,ZnO and TiO2 nanoparticles were detected u-sing transmission electron microscope (TEM)and dy-namic light scattering (DLS ).EC-9706 and EC-109 cells were treated with different concentrations of CuO, ZnO and TiO2 (5 ~80 mg · L-1 ).The cell prolifera-tion was analyzed by MTT assay.The cell cycle and apoptotic rates were determined by flow cytometry (FCM).The cell invasion was assayed in Transwell chambers.The expression of Bcl-2 and caspase-3 pro-tein in cells was detected by Western blot method.Re-sults CuO,ZnOandTiO2nanoparticleswerespheri-cal with primary particle size 12,20. 6,12 nm.The particles were agglomerated in water and cell culture medium with negative charge.CuO and ZnO nanoparti-cles induced decreases in EC-9706 and EC-109 cell vi-ability dose-dependently.After exposed to increasing concentrations of CuO and ZnO nanoparticles,the cell cycle analysis revealed a decreasing proportion of cells in G2/Mand S phase,and up-regulation of the cells in G0/G1 phase.Apoptotic cells also increased along with decreased cell invasion upon CuO and ZnO treatment. Nanoparticles treatment after 48 h, the activated caspase-3 expression quantity increased significantly and the Bcl-2 expression quantity decreased obviously (P<0. 05 )compared with control group.TiO2 nanop-articles had no obvious effect on the EC-9706 and EC-109 cell proliferation,cell cycle,apoptosis and inva-sion.Conclusion ComparedwithTiO2,CuOand ZnO nanoparticles can inhibit EC-9706 and EC-109 cell viability and metastatic potential,the mechanism of action involves cell cycle arrest in G0/G1 phase and apoptosis.These findings can help the development of nanoparticles as anti-cancer therapeutics for esophageal cancer.

Preparation of TiO2 Nano-materials and Photocatalytic Purification of Sewage / 环境与健康杂志

The recent research progress of photo-catalyzed degradation of organic pollutants by TiO2 is reviewed,the characteristics of hydrothermal method and the prepared processes of TiO2 were discussed,the photo-catalyzed mechanism under UV and visible light and the application of degradation of sewage using TiO2 nanomaterials from five aspects were described in this paper. The main problems existing in the studies of TiO2,the research directions,and the development prospects were also discussed.