Nano-sized 58S bioactive glass enhances proliferation and osteogenic genes expression of osteoblast-like cells.

OBJECTIVE: To observe the effects of ionic dissolution products on nano-sized 58S bioactive glass (nano-58S) on proliferation and specific osteogenic genes expression in MG-63 cells. METHODS: Ionic dissolution products were prepared by incubating nano-58S or sol-gel bioactive glass 58S (58S) particulates in Dulbecco's modified Eagle's medium (DMEM) at 1% w/v for 24 hr and filtrated through 0.22 µm filters to remove the particulates. MG-63 cells were cultured in the nano-58S extraction, 58S extraction, and DMEM, respectively, for different time periods to assay the proliferation, mRNA expression of alkaline phosphatase (ALP), Cbfa1, Collagen type I (Col-I) and osteocalcin (OCN), as well as ALP staining, activity and matrix mineralisation. RESULTS: In the nano-58S group, cell proliferation and mRNA expression of ALP, Cbfa1 and OCN were significantly enhanced in a time-dependent manner compared with the control group. mRNA expression of Cbfa1 on day 4 and OCN on day 7 was significantly higher than that in the 58S group. Moreover, there was significantly more ALP protein expression and mineralisation in the nano-58S group than in the 58S group. CONCLUSION: The nano-58S enhanced proliferation, osteogenic markers expression in MG-63 cells and induced stronger mineralization than 58S.

[Study on oral Candida albicans apoptosis in vitro].

PURPOSE: Candida albicans is one of the main opportunistic pathogen for human , the aim of this study is to investigate the phenomena of apoptosis in oral Candida albicans induced by acetic acid. METHODS: The Candida albicans of clinical strains were induced to apoptosis by using a weak acid acetic acid.The apoptosis was detected by flow cytometry and TEM. The data were processed for Chi-square test using SPSS11.5 software package. RESULTS: Oral Candida albicans had classic apoptosis when induced by proper concentration of acetic acid, and different concentrations of acetic acid had variable ability of inducing apoptosis of Candida albicans. CONCLUSIONS: Apoptosis can be detected in clinical strains of Candida albicans, the mechanism of apoptosis needs further research for the purpose of developing new antifungal drugs. Supported by National Natural Science Foundation of China(Grant No.30400498) and 2007 National College Student Innovative Planning Project.