Influence of Calcium Hydroxide–loaded Microcapsules on Osteoprotegerin and Receptor Activator of Nuclear Factor Kappa B Ligand Activity

Introduction

Calcium hydroxide (Ca[OH]₂) microcapsules were synthesized to allow controlled release of Ca(OH)₂. The aim of this study was to evaluate the influence of Ca(OH)₂ microcapsules on osteoprotegerin (OPG) activity, receptor activator of nuclear factor kappa B ligand (RANKL) activity, and the OPG/RANKL ratio compared with pure Ca(OH)₂ powder and Vitapex (Neo Dental Chemical Products Co Ltd, Tokyo, Japan).

Methods

One formula of Ca(OH)₂ microcapsules was evaluated, and pure Ca(OH)₂ powder was used as a control. A commonly used Ca(OH)₂ medication containing an oily vehicle (Vitapex) was also evaluated, and the in vitro release profile of Vitapex was studied. The human osteosarcoma cell line MG63 was used to evaluate the influence of Ca(OH)₂ microcapsules, pure Ca(OH)₂ powder, and Vitapex on OPG and RANKL activity. The relative messenger RNA (mRNA) expression of OPG and RANKL was determined by real-time polymerase chain reaction. The protein expression of OPG and RANKL in supernatants was measured using enzyme-linked immunosorbent assay.

Results

Vitapex prolonged the release of Ca(OH)₂ compared with pure Ca(OH)₂ powder, and the release rate of Vitapex was faster than that of the microcapsules. The OPG/RANKL ratio in the microcapsules group was up-regulated at both the mRNA and protein levels compared with the negative control group and the pure Ca(OH)₂ powder group. The ratio in the Vitapex group was lower than the microcapsule group both at the mRNA and protein levels.

Conclusions

Ca(OH)₂ microcapsules increased the expression of OPG although they did not increase the expression of RANKL compared with pure Ca(OH)₂ powder and Vitapex. This increase in expression led to an increase in the OPG/RANKL ratio and eventual inhibition of osteoclast activity.     

阿奇霉素微囊的制备与质量控制

目的:制备阿奇霉素微囊,并建立其质量控制方法。方法:以明胶为囊材,阿奇霉素为主药制备微囊。采用紫外分光光度法于482nm波长处测定阿奇霉素的含量,同时考察微囊的形态、粒径、载药量、包封率等指标。结果:所制微囊呈圆形,粒径均匀,平均体积径为100.96μm,平均载药量为23.8%,平均包封率为(68.72±0.89)%。阿奇霉素检测浓度的线性范围为7.5～52.5mg·L-1,平均回收率为(99.5±1.02)%,RSD=1.03%。结论:该制剂制备工艺可行,含量测定方法简便、可靠。     

Islet transplantation in the future: Use of a bioartificial pancreas

Tight glycemic control effectively delays the onset and slows the progression of diabetic complications in patients with insulin-dependent diabetes mellitus. Successful pancreas transplantation corrects abnormal glucose metabolism but subjects patients to morbidity and mortality associated with chronic immunosuppression. Immune exclusion devices containing pancreatic islets (bioartificial pancreas devices) are designed to provide glycemic control through islet transplantation without immunosuppression. The immune exclussion is achieved by separating allogeneic or xenogeneic islets from the host by semipermeable membranes that allow only small molecules, such as glucose, insulin, and nutrients, to pass through. Immune lymphocytes and immunoglobulins are excluded by the membrane and are unable to cause destruction of the islets. This report provides a brief review of three types of bioartificial pancreas devices used for the treatment of diabetes, i.e., perfusion-based vascular devices, diffusion-based chambers and microcapsules, and describes recent progress in each area.     

吡哌酸缓释微囊的体外溶出特性考察

考察了不同主药含量、不同粒径的吡哌酸缓释微囊的药物溶出特性及在不同pH介质中的溶出行为,探讨了微囊中吡哌酸含量对微囊结构、半数测出时间T_(50)及药物渗透性的影响与因不同pH介质中由于药物溶解度不同而引起的溶出行为的改变。证实了微囊释药符合Higuchi方程,其结构与药物含量有关,药物渗透性及T_(50)~(1/2)与药物含量存在线性相关性,药物溶出因微囊粒径减小、药物于介质中溶解度增加而增加。     

吡喹酮微囊的研制

以生物可降解的明胶为囊材，采用单凝聚法制得流动性粉末状的吡喹酮微囊。其平均容积径为８２．６６μｍ。用差示热分析法求得其热解活化能为３３７．０９ｋＪ／ｍｏｌ。建立了一阶导数分光光度法测定微囊内药物含量，三批平均为１４．２％，平均回收率为９７．９％，ＲＳＤ为１．７２％，平均包封率为８１．１％。     

12-O-(对硝基苯甲酰)二氢青蒿素聚L-乳酸微囊的制备研究

用聚乳酸为囊材制备12-O-(对硝基苯甲酰)二氢青蒿素(79019)微型包囊以期达到注射后该化合物在体内缓释的目的。使用本文介绍的液中干燥法,可使具疏水性的本品包入囊内。对微囊内含物的体外释放和影响囊径分布的因素进行了较详尽的研究。     

玉米多孔淀粉-海藻酸钠-壳聚糖-葡萄多酚缓释微胶囊的制备及表征

目的为提高葡萄多酚的稳定性和强化缓释效果,采用玉米多孔淀粉为芯材载体复合凝聚法制备葡萄多酚微胶囊。方法以包埋率为主要指标,通过单因素试验和正交试验考察了各因素对葡萄多酚微胶囊化的影响,并对其制备工艺进行优化。结果优选的最佳工艺为25 mg/m L葡萄多酚溶液10 m L,玉米多孔淀粉用量1.5 g,在质量浓度0.03 g/m L海藻酸钠溶液30 m L、0.01 g/m L壳聚糖溶液50 m L、0.05 g/m L氯化钙溶液50 m L、p H 3.5时制得的微胶囊外观较优,粒径分布主要在600~850μm,葡萄多酚包埋率为83.2%,微胶囊产品在模拟胃液和肠液环境中具有很好的释放特性。结论以玉米多孔淀粉为芯材载体,海藻酸钠-壳聚糖为壁材制备的葡萄多酚微胶囊产品的形态及包埋率要优于单纯的海藻酸钠-壳聚糖微胶囊。用红外光谱和扫描电镜对葡萄多酚缓释微胶囊结构进行表征,均证实包埋物制备成功。     

Preparation of magnetic and pH-responsive chitosan microcapsules via sonochemical method

Magnetic and pH-responsive chitosan microcapsules (MPRCMCs) were prepared by a simple sonochemical method. Superparamagnetic oleic acid modified Fe₃O₄ nanoparticles (OA-Fe₃O₄ NPs) and hydrophobic drugs could be directly loaded into MPRCMCs during sonication. The obtained microcapsules had a well-defined spherical morphology with the average size of 2?μm. The microcapsules showed an excellent magnetic property. In addition, the pH-responsive controlled release of coumarin 6 (C6) from MPRCMCs indicated that the developed microcapsules could be a promising candidate for drugs carriers.     

大豆异黄酮-壳聚糖-海藻酸钠缓释微囊抗衰老能力的实验研究

[目的]制备大豆异黄酮-壳聚糖-海藻酸钠缓释微囊,并从药代动力学和抗衰老的动物学效应对其进行评价。[方法]采用壳聚糖-海藻酸钠包埋体系和自主研发的离心筛制粒机制备大豆异黄酮缓释微囊,以市售大豆异黄酮非缓释剂型为对照,将受试ICR小鼠分为缓释、非缓释两个实验组,以及模型、空白两个对照组。连续灌胃30天,通过Morris水迷宫检测小鼠的学习和记忆能力,并分别采血浆、脑匀浆液,测定血浆丙二醛（MDA）含量,脑匀浆液MDA含量、过氧化物歧化酶（SOD）活力,根据以上检测指标评价缓释微囊的抗衰老效应。同时,将家兔分为缓释、非缓释以及空白组。受试测试药物后于不同时间点测定其血药、尿药浓度以及微囊在动物消化系统中的状态。[结果]经壳聚糖-海藻酸钠包埋体系制备的大豆异黄酮缓释微囊在受试药物后6~12小时开始崩解并释放药物,延长了大豆异黄酮的生物半衰期,而水迷宫实验及小鼠血、脑组织的MDA、SOD水平等指标结果表明,缓释微囊可提高小鼠的学习能力以及记忆力,降低小鼠血浆以及脑组织MDA含量,增加SOD活性,充分发挥大豆异黄酮抗衰老的生物学功效,与非缓释组比较,差异有统计学意义。[结论]对比现有市场剂型,大豆异黄酮-壳聚糖-海藻酸钠缓释微囊能更好地提高动物学习能力及记忆力,降低血浆与脑中MDA含量,提高脑SOD活力,具有非常优越的缓慢释放特性,充分发挥大豆异黄酮的抗衰老生物学效应。     

二氧化钛微囊防晒霜的研制

目的 制备含纳米二氧化钛的聚电解质微囊防晒霜,并考察制剂的结构和防晒性能。 方法 以碳酸钙粒子为核心,通过静电吸附原理将聚电解质4-苯乙烯磺酸钠和纳米二氧化钛交替逐层包裹在核心表面形成微囊,加入辅料,按常规方法制备防晒霜。利用扫描电镜和共聚焦显微镜观察微囊结构;防晒系数分析仪测定制剂的防晒性能。 结果 二氧化钛微囊外观圆整,平均粒径为(5.46±1.05) μm,微囊防晒霜防晒SPF值为30.31±2.56。 结论 含纳米二氧化钛的聚电解质微囊防晒霜防晒的效果优于普通二氧化钛防晒霜。