ABSTRACT
No matter what kind of therapies you choose, clear aligner treatment (CAT) or fixed orthodontic treatment (FOT), the therapy must be performed on the basis of periodontal health and follow the rule that the treatment cannot be harmful to the periodontal tissues. Doctors and patients prefer the clear aligner treatment because of its features, such as aesthetic, removable and comfortable. There are many studies which consider the influences of CAT on the periodontal health, and the conclusions are relatively consistent. The CAT is more beneficial for the plaque-control and maintaining the periodontal health. However, there are a few articles which are talking about applying the CAT to the patients with severe periodontitis. This article mainly reviews the effect of CAT towards the patients with periodontitis, and provides some reference when the patients with severe periodontitis need to choose a proper treatment.
ABSTRACT
BACKGROUND: Previous research has indicated that graphite carbon nanoparticles have a strong adsorbability. While, when the concentration is effectively controlled, graphite carbon nanoparticles also have well compatibility and sensitizing effect. OBJECTIVE: To observe the morphology of graphite carbon nanoparticles, and to investigate the effects of graphite carbon nanoparticles on cell proliferation and ultramicrostructure.METHODS: Graphite carbon nanoparticles (0.5 g) were put in 100 mL triple distilled water to obtain graphite carbon nanoparticle mother liquid after oscillation and microfiltration. HepG2 cells, L02 cells, HI7702 cells, and 3T3 cells in the logarithmic phase were adjusted to the concentration of 5×10~7/L and inoculated in 6-well culture plate with 0.5 mL per well. Thereafter, the cells were cultured with RPMI-1640 culture media (1.5 mL) containing fetal bovine serum, penicillin, and streptomycin. The original culture solution was removed after 24 hours. The 1-5 wells were considered as the experimental group, and 25, 10, 7.5, 5, 0.25 mg/Lgraphite carbon nanoparticles (2.0 mL) were respectively added into each well; while, the sixth well was considered as the blank control group without graphite carbon nanoparticles. The cells in the blank control group were cultured for 24 hours. Particle diameter was measured using atomic force microscopy; morphology was observed using electron microscope; effect of different concentrations of graphite carbon nanoparticles on cell number was detected using hemacytometry under optic microscope; the effect of 7.5 mg/L graphite carbon nanoparticles on ultramicrostructure was observed under transmission electron microscope. RESULTS AND CONCLUSION: Graphite carbon nanoparticles were around and 20 nm diameter. Compared with the blank control group, cell numbers except HepG2 cells were increased, especially the effect of 7.5 mg/L graphite carbon nanoparticles was greatest (P < 0.05). Transmission electron microscope indicated that graphite carbon nanoparticles were distributed into cells, including cytoplasm, nucleus, and mitochondrion; while, subcellular structure damage and cell apoptosis and necrosis were absent. Graphite carbon nanoparticles have no side effects on in vitro cultured cells and can promote cell proliferation, showing a dose-dependence correlation, especially the concentration of 7.5 mg/L.
ABSTRACT
BACKGROUND: Naked plasmid DNA cannot transfect cells effectively because of negative charge and the degradation of nuclease. Chitosan is a biodegradable natural cationic polysaccharide. It can provide effective protection against DNases and enhance transfection efficiency.OBJECTIVE: To prepare chitosan nanoparticles loaded with pcDNA3.1(-)/MAGE-3-HSP70 by complex coacervation method and to research its characteristics.DESIGN, TIME AND SETTING: A controlled experiment was performed at the Key Laboratory of Nano-biotechnology, National Ministry of Public Health of China from February to August 2009.MATERIALS: pcDNA3.1 (-)/MAGE-3-HSP70 was constructed at the Key Laboratory of Nano-biotechnology, National Ministry of Public Health of China. Chitosan, deacetylation degree > 90.0%, viscosity < 100 cps, batch number 060306, was obtained from Shanghai Bio Life Science & Technology Co., Ltd. B16 cells were presented by the Institute of Oncology, Central South University. METHODS: Chitosan nanoparticles loaded with pcDNA3.1(-)/MAGE-3-HSP70 were prepared by complex coacervation method. Then the naparticles were transfected into B16 cells, and the level of MAGE-3-HSP70 mRNA was tested using reverse transcription-polymerase chain reaction (RT-PCR) technology. The in vitro cytotoxicity of the nanoparticles was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl (MTT) assay.MAIN OUTCOME MEASURES: Particle diameter and Zeta potential were determined by ZetaSizer 1000HSA. Efficiency of the encapsulation was measured with a spectrophotometer. The combination manner was observed by gel retardation test. The ability to protect plasmid DNA from Dnase I degradation was evaluated by DNase Ⅰ protection test. RESULTS: The mean diameter of chitosan plasmid DNA nanoparticles was 223 nm, its zeta potential was 16 mV. The encapsulation efficiency of DNA was 92.3%. The transfection efficiency of chitosan plasmid DNA nanoparticles by B16 cells was about equivalent to that of the Lipofectamine 2000 reagent. Chitosan plasmid DNA nanoparticles were much less cytotoxlc when compared with Lipofectamine 2000-pDNA complexes.CONCLUSION: Chitosan plasmid DNA nanoparticle were nontoxic to cultured cells and plasmid DNA can be efficiently transferred into B16 cells by chitosan nanoparticles.