Poly(ortho ester) nanoparticles targeted for chronic intraocular diseases: ocular safety and localization after intravitreal injection

Treatment of posterior eye diseases is more challenging than the anterior segment ailments due to a series of anatomical barriers and physiological constraints confronted by drug delivery to the back of the eye. In recent years, concerted efforts in drug delivery have been made to prolong the residence time of drugs injected in the vitreous humor of the eye. Our previous studies demonstrated that poly(ortho ester) (POE) nanoparticles were biodegradable/biocompatible and were capable of long-term sustained release. The objective of the present study was to investigate the safety and localization of POE nanoparticles in New Zealand white rabbits and C57BL/6 mice after intravitreal administration for the treatment of chronic posterior ocular diseases. Two concentration levels of POE nanoparticles solution were chosen for intravitreal injection: 1.5?mg/ml and 10?mg/ml. Our results demonstrate that POE nanoparticles were distributed throughout the vitreous cavity by optical coherence tomography (OCT) examination 14 days post-intravitreal injection. Intraocular pressure was not changed from baseline. Inflammatory or adverse effects were undetectable by slit lamp biomicroscopy. Furthermore, we demonstrate that POE nanoparticles have negligible toxicity assessed at the cellular level evidenced by a lack of glia activation or apoptosis estimation after intravitreal injection. Collectively, POE nanoparticles are a novel and nontoxic as an ocular drug delivery system for the treatment of posterior ocular diseases.     

Caffeic acid phenethyl ester,a propolis polyphenolic,attenuates potentially cadmium-induced testicular dysfunction in mice

Abstract

Cadmium (Cd) as environmental pollutant can induce severe damage, particularly to the testis. This study investigated the effects of Caffeic acid phenethyl ester (CAPE) on testicular dysfunction induced by Cd. Adult mice were intraperitoneally injected with cadmium chloride (CdCl₂) with different doses of CAPE pretreatment. After CdCl₂ injection, body/testis weight ratio decreased, Cd levels accumulated and zinc levels decreased in testis. Furthermore, Cd intoxication caused a significant increase of oxidative stress levels, antioxidant enzymes activities, and glutathione levels. Interestingly, significant improvements were observed after the administration of CAPE. Our results demonstrated the protective effect of CAPE, linking Cd testicular dysfunction to oxidative stress.     

l-DOPA induces concentration-dependent facilitation and inhibition of presynaptic acetylcholine release in the guinea-pig submucous plexus

Neurotransmitter- or neuromodulator-like actions ofl-DOPA were investigated with intracellular recordings from submucous plexus neurons of the guinea-pig caecum.l-DOPA at 30 nM augmented the amplitude of fast EPSPs, but did not affect depolarizations elicited by puff application of acetylcholine (ACh). The augmenting effect ofl-DOPA on the fast EPSPs was counteracted byl-DOPA methyl ester. The fast EPSPs were depressed by 10 μMl-DOPA, but transiently augmented after rinsing the drug.l-DOPA methyl ester did not affect the inhibitory action ofl-DOPA on the fast EPSPs, but antagonized the potentiation following the inhibition. The depolarization elicited by exogenously applied. ACh was inhibited by 10 μMl-DOPA. Intracellular Ca²⁺ concentrations ([Ca²⁺]_i) of the neuronal soma were measured with fura-2 microfluorophotometry. The transient increase in the [Ca²⁺]_i evoked by the somatic action potential (Δ[Ca²⁺]_AP) was facilitated by 30 nMl-DOPA, but decreased by the drug at 10 μM. It is concluded thatl-DOPA at low concentrations enhances the Δ[Ca²⁺]_AP, increasing the neurotransmitter release, but at high dose diminishes the Δ[Ca²⁺]_AP, inhibiting the neurotransmission.     

L—NAME促进大鼠红藻氨酸诱导性发作

为证明癫痫发作早期一氧化氮（ＮＯ）抗发作效应，用ＮＯ合酶（ＮＯＳ）抑制剂Ｌ－硝基精氨酸甲酯（Ｌ－ＮＡＭＥ）对大鼠红藻氨酸（ＫＡ）诱导性发作进行干预，同时用分光光度法检测海马结构中ＮＯＳ活性的早期变化。发现ＫＡ发作１０ｍｉｎ、３０ｍｉｎ组海马结构中ＮＯＳ活性明显升高，而ＫＡ注射前３０ｍｉｎ给予Ｌ－ＮＡＭＥ可显著抑制ＮＯＳ活性的升高，这种抑制效应与大鼠ＫＡ发作中湿狗样摇动（ＷＤＳ）的提早出现和发生次数增多显著相关。结果提示在ＫＡ诱导大鼠发作早期内源性ＮＯ具有明显的抗发作效用。     

薄层扫描法测定复脉定冲剂中远志有效成分的含量

采用薄层扫描法对复脉定冲剂中远志有效成分３，４，５－三甲氧基反式肉桂酸乙酯的含量进行测定。方法简单、快速，结果可靠，可作为该制剂的质控标准。     

党参总碱对东莨菪碱引起小鼠记忆障碍和脑内乙酰胆碱及胆碱乙酰化酶的作用

用跳台法观察到党参总碱(DSA)能改善东莨菪碱(Scop)引起的记忆障碍,并能对抗Scop所致小鼠脑内乙酰胆碱(ACh)浓度下降及胆碱乙酰化酶(ChAT)活性的降低。体外实验发现当在反应液中加入DSA后,ChAT生成ACh的量增加。     

四逆汤煎煮过程中乌头类生物碱的溶出和水解平衡

目的 研究四逆汤中乌头类生物碱的溶出平衡和水解平衡。方法 利用电喷雾质谱分析，比较了制附子、四逆汤、四逆汤药渣和含有3种双酯型生物碱的混合对照品体系中的乌头碱类二萜生物碱。结果 在煎煮过程中双酯型生物碱溶解并发生水解反应，而脂类生物碱则难溶于水。乌头碱、中乌头碱、次乌头碱水溶性相近，但是次乌头碱在水中的热稳定性更高，C19二萜骨架上C3取代基(—OH或—H)的变化影响生物碱的稳定性。结论四逆汤中的乌头碱类生物碱的种类及含量由其溶解性和化学稳定性共同决定。     

维胺酯-β-环糊精包合物的研究

应用３因素８水平的均匀设计方法，优化出维胺酯－β－环糊精包合物最佳制备条件，所得包合物的包合率为９９．３％，其表观稳定常数为１３９４Ｍ－１．