Effects of fluoridation of porcine hydroxyapatite on osteoblastic activity of human MG63 cells

Abstract

Biological hydroxyapatite, derived from animal bones, is the most widely used bone substitute in orthopedic and dental treatments. Fluorine is the trace element involved in bone remodeling and has been confirmed to promote osteogenesis when administered at the appropriate dose. To take advantage of this knowledge, fluorinated porcine hydroxyapatite (FPHA) incorporating increasing levels of fluoride was derived from cancellous porcine bone through straightforward chemical and thermal treatments. Physiochemical characteristics, including crystalline phases, functional groups and dissolution behavior, were investigated on this novel FPHA. Human osteoblast-like MG63 cells were cultured on the FPHA to examine cell attachment, cytoskeleton, proliferation and osteoblastic differentiation for in vitro cellular evaluation. Results suggest that fluoride ions released from the FPHA play a significant role in stimulating osteoblastic activity in vitro, and appropriate level of fluoridation (1.5 to 3.1 atomic percents of fluorine) for the FPHA could be selected with high potential for use as a bone substitute.     

Forms of occurrence of fluorine in drinking water

Alum coagulation and fluoridation are common processes in many water treatment plants. Under these conditions, fluorine may be present in treated water as less physiologically active fluoroaluminates. This study reports the results of a mathematical analysis of the corresponding chemical equilibria. The influence of at least two possible side-reactions must be taken into account (protonation and hydrolysis). In neutral and alkaline solutions, fluoroaluminates will be, under given conditions, converted to hydroxoaluminates so that the total fluoride concentration can be considered approximately equal to the free fluoride ions. In acid solutions the presence of fluoroaluminates might be significant.     

2-羟基-3-三氟甲基吡啶的合成

以2-氯烟酸为原料,经氟代、水解制备得到目标化合物,收率66.3%。考察了反应时间、反应温度、投料比分别对氟化反应、水解反应的影响。适宜的反应条件为:氟化反应时间为12h,氟化反应温度为60℃,n(2-氯烟酸)∶n(SF_4)=1∶6;水解反应时间为8h,水解温度为70℃,n(2-氯-3-三氟甲基吡啶)∶n(KOH)=1∶2.5。     

氟化聚乙烯高分子材料化学稳定性研究

分析了聚乙烯高分子材料氟化后化学稳定性增强的原理,并选用经过氟化处理的聚乙烯微球进行了耐油实验。结果表明,经氟化处理后的聚乙烯微球表面形成了一层有效的阻隔层,能够阻止油分子进入微球内部。     

流态化法氧化钕氟化实验的研究

在直径80 mm振动流化床中,研究Nd2O3超细颗粒常温条件下的流化状态,考察了粉体物性,粉体填料量和流化速度等因素对原料Nd2O3流化质量的影响.由此确定了后期高温氟化反应的最佳流化速度和初始床层高度.并探索了不同条件下NdF3产品的氟化率,实验结果表明,在600℃下反应时间30min为相对最优氟化条件.     

氟化物激光晶体Nd3+:LiYF4的坩埚下降法生长

本文报道了氟化物激光晶体Ｎｄ＾３＋：ＬｉＹＦ４的坩埚埚下降法生长工艺,采用经氟化处理的无水氟化物原料,按照ＬｉＦ：ＹＦ３＝５１５：４８．５的比例配料,控制炉体温度于９２０－９６０℃,晶体生长速度为０．４－０．８ｍｍ／ｈ,通过密闭条件下的坩埚下降法生长出尺寸为φ２５ｍｍ＊８０ｍｍ的完整单晶。     

Atmospheric Pressure Plasma Activation of Hydroxyapatite to Improve Fluoride Incorporation and Modulate Bacterial Biofilm

Despite the technological progress of the last decade, dental caries is still the most frequent oral health threat in children and adults alike. Such a condition has multiple triggers and is caused mainly by enamel degradation under the acidic attack of microbial cells, which compose the biofilm of the dental plaque. The biofilm of the dental plaque is a multispecific microbial consortium that periodically develops on mammalian teeth. It can be partially removed through mechanical forces by individual brushing or in specialized oral care facilities. Inhibition of microbial attachment and biofilm formation, as well as methods to strengthen dental enamel to microbial attack, represent the key factors in caries prevention. The purpose of this study was to elaborate a cold plasma-based method in order to modulate microbial attachment and biofilm formation and to improve the retention of fluoride (F⁻) in an enamel-like hydroxyapatite (HAP) model sample. Our results showed improved F retention in the HAP model, which correlated with an increased antimicrobial and antibiofilm effect. The obtained cold plasma with a dual effect exhibited through biofilm modulation and enamel strengthening through fluoridation is intended for dental application, such as preventing and treating dental caries and enamel deterioration.     

含氟水治理方法的分析

综述了近年来国内外在各种除氟方法上的研究进展情况 ,并介绍了铝酸钙渣除氟的有关情况     

The Effect of Sintering Processes on the Properties of Mn-F Doped PZT Ceramics

Fluoridated PZT ceramics were produced by solid-state and liquid-phase sintering methods, according to the formula Pb(Zr_0.52Ti_0.48)_1-xMn_xO_3-yF_y, where 0 < x < 0.015 and 0 < y < 0.1. The effects of sintering processes on the phase development and microstructure of Mn-F doped PZT ceramics have been investigated using XRD and FEGSEM. In solid-state sintering, the fluoride additive enhanced the densification of PZT ceramics, enabling densification to >95% relative density at a temperature as low as 1000°C. However, fluoride loss at high temperatures was found to be a significant problem. Alternatively, ceramics with a density >92% were prepared by sintering at a temperature of 850°C by incorporating a eutectic mixture of PbO and V₂O₅ as sintering aid. Problems associated with volatilization of fluoride compounds during sintering could be alleviated using this approach. EPMA was employed to analyze the distribution of the additives in the calcined powders and sintered ceramics. The nonlinear dielectric properties were determined by measuring P-E loops, using an AC electric field in the range 0.1 to 2.0 kV mm^?1.     

杯[4]芳烃咪唑盐的微波合成及在氟化反应中的应用

以杯[4]芳烃为起始原料,首先制得中间体杯[4]芳烃双溴代烷基衍生物,然后经微波辐射和阴离子交换,共得9种杯[4]芳烃咪唑盐衍生物,化合物的结构与构象经元素分析、IR、1HNMR、19FNMR、31PNMR表征.研究了它们在对氯硝基苯氟化反应中的催化性能以及对K+的萃取性能.结果表明,这9种化合物在氟化反应中的催化效果良好,对氟硝基苯的收率为80.89％～92.67％;同时化合物对K+具有较好的萃取效果,其中以化合物25,27-二[4-(3-甲基咪唑)乙氧基]-26,28-二羟基-5,11,17,23-四叔丁基杯[4]芳烃六氟磷酸盐的萃取效果最好,萃取率可达75.45％.