盐酸乌拉地尔PLLA微球的制备及性能研究

采用溶剂挥发法制备盐酸乌拉地尔PLLA微球并通过SEM对其结构进行了表征,同时对微球的包封率和药物释放进行了测试。通过有机相加入乙醇或外水相加入盐的方法可以提高微球对药物的包封率。结果表明,当无水乙醇与三氯甲烷的比为1:2时,制得的微球包封率最高,达到30.52%。外水相中加入盐类电解质的方法也能提高药物的包封率。盐的加入使得盐酸乌拉地尔在外水相的溶解度降低,减少了药物向外水相的泄漏,从而提高了药物的包封率。其中KCl的加入对药物包封率的影响最大。当KCl浓度达到0.4%(mol)时,微球的包封率最高,达到35.52%。体外药物释放结果表明,PLLA微球具有明显的缓释作用,其释药动力学满足Higuchi方程。     

壳聚糖-明胶载药微球的制备及释放性能

以壳聚糖（Cs）和明胶（Gel）为原料,采用乳液凝聚法制备了对药物具有缓释作用的微球。以异喹啉为模拟药物,分别通过丙酮浸泡载药／常温干燥法和盐酸浸泡载药／氢氧化钠再生／冷冻干燥法,制得不同载药量的微球,并对其包封率和释放行为进行了研究。结果表明,当戊二醛（GD）与壳聚糖（Cs）的质量比为0．40～0．53,载药量在20％～30％（质量分数）之间时,壳聚糖-明胶载药微球15h后释放75％左右,包封率可以达到40％～50％,为将壳聚糖。明胶共混微球应用于生物医学领域提供了试验基础。     

美洛昔康PLA缓释微球的制备及性能研究

以生物可降解材料聚乳酸(PLA)作为载体,聚乙烯醇为分散剂,二氯甲烷为溶剂,采用乳化-溶剂挥发法制备美洛昔康(Meloxicam)聚乳酸缓释微球。用生物显微镜和扫描电子显微镜观察微球形态,用傅里叶红外光谱仪检测美洛昔康是否已存在于微球中,用紫外-可见分光光度计测定了微球的包封率、载药量及其体外释药特性。结果表明:美洛昔康聚乳酸缓释微球光滑圆整,聚乳酸和美洛昔康能够有机地结合为一体,微球载药量为12.72%,包封率为89.04%,美洛昔康/PLA微球体外释放80 h后累积释药率达70%以上,具有显著的缓释作用。     

聚乳酸硝苯地平缓释微球的制备与释药性能研究

以熔融缩聚制得的聚乳酸（PLA）作为载体,以聚乙烯醇为分散剂,二氯甲烷为溶剂,采用乳化-溶剂蒸发法制备聚乳酸硝苯地平（PLA／NFD）缓释微球。通过红外光谱（FT—IR）和生物显微镜对聚乳酸硝苯地平缓释微球进行了表征,并用紫外分光光度法探讨了聚乳酸硝苯地平缓释微球的释药性能。结果表明：聚乳酸硝苯地平缓释微球呈现以光滑完整的球形,且聚乳酸和硝苯地平药物能够有机地结合为一体。合成的聚乳酸硝苯地平球形微球具有明显的缓释作用,而且增大硝苯地平,聚乳酸投药比,会提高微球的释放度,但包封率下降。     

负载药物替莫唑胺的纳米羟基磷灰石/聚乳酸-羟基乙酸共聚物微球的缓释行为

以聚乳酸-基乙酸共聚物(PLGA)和纳米羟基磷灰石(nHA)作为生物降解材料制备了药物替莫唑胺(Temozolomide,TMZ)的缓释系统.采用湿法化学工艺制备了球状和棒状的nHA粉末.将TMZ药物分子负载在nHA表面(nHA-TMZ),再通过乳化溶剂挥发法将nHA-TMZ包裹在PLGA微球中,同时研究了微球中nHA的形貌和含量对缓释微球物化性能的影响.用扫描电镜、紫外分光光度计分别测定了微球的结构、形貌、药物包封率和缓释行为.相比于不含有nHA的TMZ/PLGA缓释微球,nHA的介入能够显著提高药物的包封率,并且包封率与nHA的加入量有关.此外,药物释放实验表明包裹在微球中的nHA的形貌和溶解速率能够影响微球的缓释行为.     

盐酸帕洛诺司琼PLGA缓释微球的制备与研究

为了降低盐酸帕洛诺司琼给药频率,提高对延迟性化疗相关性恶心呕吐(CINV)的缓解作用,本研究以聚乳酸-羟基乙酸共聚物(PLGA)为载体,制备盐酸帕洛诺司琼PLGA缓释微球(Pal-MS),并对其体外释药特性进行评价。结果表明,外水相pH值和药物/PLGA质量比可显著影响Pal-MS包封率和药物释放。当外水相pH为7. 0,药物/PLGA质量比为1∶39时,PalMS包封率高达82. 75%,体外7 d内呈现零级释药特征(y=0. 1163x-0. 0006,R~2=0. 9944),有望制备出可在体内缓释一周的制剂。     

改性聚乳酸载药微球的制备及性能

以尼莫地平为模型药物,聚乳酸(PLA)为载体材料,采用溶剂蒸发萃取法制备了N-乙烯基吡咯烷酮(NVP)接枝聚乳酸共聚物(PLA-g-PVP)微球,考察了聚乳酸质量分数、乳化剂质量分数、转速和投药质量比对微球的影响。采用红外光谱、差式扫描量热分析表征药物与载体的相互作用,扫描电镜观察微球表面形态,对不同接枝率共聚物微球的粒径、载药量、包封率及体外释放性能进行研究。结果表明,当w(PLA)=4%,w(乳化剂)=3%,转速9 000 r/min,投药质量比为2∶3时,不同接枝率改性聚乳酸微球形态圆整,平均粒径小于10μm,粒径分布窄,微球可连续释放14 d以上,释放速率随着接枝率增大而增大。     

小檗碱壳聚糖微球制备及其抗真菌活性测定

采用乳化-化学交联法制备了负载小檗碱的壳聚糖微球. 以正交实验对微球形态、粒径、药物包封率和载药率等指标进行了制备工艺条件优化. 显微镜和电镜观察显示微球球形良好,表面光滑,平均粒径约15 mm,包封率为78.98%,载药率为4.78%. 持续30 d的药物释放实验表明,小檗碱可从微球中缓慢释放. 利用生长速率法测定了微球对3种重要植物病原真菌的抑制作用,5 mg/mL微球对番茄早疫病菌(Alternaria solani)的抑菌率达65%.     

聚乳酸—聚乙二醇嵌段共聚物胶束的制备及性能研究

分别以聚乙二醇(PEG)及聚乙二醇单甲醚(m PEG)引发L-丙交酯开环聚合得到PLLA(聚乳酸)-PEG-PLLA三嵌段与PLLA-m PEG两嵌段共聚物,通过1H-NMR分析确定共聚物的结构及分子量。采用直接溶解法和有机溶剂挥发法制备PLLA-PEG-PLLA及PLLA-m PEG胶束,并用TEM对其形态进行表征。利用激光粒度分析和染料探针的方法证实了共聚物自组装形成了胶束,且具有较小的临界胶束浓度(CMC),粒径约为100 nm。三嵌段PLLA-PEG-PLLA胶束的粒径小于两嵌段PLLA-m PEG胶束的粒径;有机溶剂挥发法制备的胶束粒径小于直接溶解法制备的胶束粒径。盐酸乌拉地尔胶束的体外释放结果表明,共聚物组成以及载药方式等对胶束载药、释药行为有一定影响,胶束对所包载的盐酸乌拉地尔具有明显的缓释作用。     

阿司匹林壳聚糖纳米缓释微球的制备及体外释放性能的研究

以自制阿司匹林为药物,壳聚糖为载体,采用乳化-化学交联法制备了阿司匹林-壳聚糖载药微球,确定了阿司匹林-壳聚糖载药微球的制备工艺条件,探讨搅拌速度、阿司匹林/壳聚糖质量比、交联剂戊二醛、乳化剂Span-80用量对微球的药物包封率、载药量和释药性能的影响。研究结果表明,室温条件下,以液体石蜡为介质,选用3%的壳聚糖冰醋酸溶液、按阿司匹林∶壳聚糖=1.5∶1、4%的戊二醛为交联剂、Span-80用量为体积比6%、中等搅拌速度制备出的微球药物包封率可达79%,微球粒径最小可达20 nm,制得的载药微球在16 h内对药物有良好的缓释作用,在25 h之内仍存在缓药效果。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.