羧甲基纤维素-大豆分离蛋白农药缓释颗粒的制备及性能

为提高农药利用率、精确控制农药释放,设计了一种pH响应型缓释颗粒。以3-氨丙基三乙氧基硅烷（APTES）为桥连接羧甲基纤维素（CMC）与大豆分离蛋白（SP）得到羧甲基纤维素-大豆分离蛋白（CMC-SP）,然后利用分子自组装法负载阿维菌素（AVM）形成载药颗粒（CMC-SP@AVM）。采用红外光谱（FTIR）、扫描电镜（SEM）、热重分析（TGA）等手段对改性产物结构和形貌进行表征,并对CMC-SP@AVM的载药性能、缓释性能、抗紫外性能、杀虫活性进行了探究。结果表明,CMC-SP@AVM具有近似椭圆形的结构,CMC-SP@AVM的平均粒径为104nm;对AVM的包封率达41.9%,并赋予AVM优异的抗紫外光分解性能,强紫外光照射120h后,CMC-SP@AVM中AVM的残留率比未包封的AVM高117%,其药物释放具有pH响应特性,pH越大,释放速率越快;药物释放过程符合Elovich模型。在相同AVM浓度下CMC-SP@AVM的杀虫活性与原药无显著差异。     

叶面亲和型阿维菌素微胶囊的制备及pH响应性释放性能

为减少农药流失，设计了一种叶面亲和型缓释微胶囊。以甲基丙烯酸甲酯（MMA）接枝改性羧甲基纤维素（CMC）得到羧甲基纤维素-聚甲基丙烯酸甲酯（CMC-g-PMMA），然后利用自组装负载阿维菌素（AVM）形成载药微胶囊（CMC-g-PMMA@AVM），通过多巴胺（DA）包覆提高CMC-g-PMMA@AVM的叶面亲和性。采用扫描电镜、红外光谱、热重分析等对其结构和形貌进行表征，研究了微胶囊的载药性能、叶面亲和性及响应释放性能。结果显示，DA/CMC-g-PMMA@AVM为平均粒径126nm的球形粒子，多巴胺的包覆可有效提高微胶囊的载药性能，包封率可达88.56%；增强AVM的叶面亲和性，使其叶面滞留量相对于阿维菌素水乳液提升30.56%；赋予AVM优异的抗紫外光分解性能，强紫外光照射60min后，由AVM水乳液中AVM的残留率14.03%提高到DA/CMC-g-PMMA@AVM中的59.55%。载药微胶囊中药物释放具有pH响应，在pH=5条件下出现爆释，药物释放过程符合Weibull模型，受Fick扩散控制。     

羧甲基壳聚糖-蓖麻油基聚氨酯农药缓释微球的制备及性能

以羧甲基壳聚糖（CMCS）、蓖麻油（CO）和异佛尔酮二异氰酸酯（IPDI）为原料，自乳化法制备了羧甲基壳聚糖-蓖麻油基聚氨酯微球（CO-CMCS-PU），通过分子自组装法负载阿维菌素（AVM）得到载药微球（CO-CMCS-PU@AVM）。采用FTIR、1HNMR、SEM、TGA等对产品结构及形貌进行表征，并探究了不同药量载药微球的包封率、缓释性能、抗紫外性能、叶面接触角和黏附性能。结果表明，相比AVM分散液，紫外照射后载药微球中AVM的保留率提高到43%，说明CO-CMCS-PU载体的抗紫外性能良好；载药微球比AVM分散液在黄瓜叶面上的接触角降低了20%以上，滞留量提高了40%以上，说明其在叶面上有较好的黏附性和润湿性；载药微球包封率可达80%以上，具有良好的缓释和pH响应释放性能，释药行为符合First-order动力学模型，药物释放受Fickian扩散控制。     

5％阿维菌素·噻唑膦复配型微胶囊悬浮剂制备及性能

[目的]为了降低阿维菌素和噻唑膦的分解以及对作物的药害,提高其药效,制备阿维菌素·噻唑膦复配型微胶囊悬浮剂。[方法]以甲苯二异氰酸酯(TDI)和乙二胺为反应单体,阿维菌素和噻唑膦为芯材,二甲苯为溶剂,采用界面聚合法制备微胶囊。[结果]该微胶囊的平均粒径为6.095μm,近似圆球形,表明光滑,阿维菌素和噻唑膦的包封率分别达到99.51%和80.86%,载药量分别为1.03%和4.02%,悬浮率分别为85.43%和97.74%。该微胶囊悬浮剂的缓释性能优于85%噻唑膦原药、20%噻唑膦水乳剂、1.8%阿维菌素乳油和3%阿维菌素水乳剂;该微胶囊悬浮剂具有优异的屏蔽紫外光降解性能。[结论]阿维菌素和噻唑膦通过界面聚合法微胶囊化后可以显著增强其缓释和屏蔽紫外光降解性能。     

树脂共混改性制备毒死蜱微胶囊

[目的]以聚甲基丙烯酸甲酯(PMMA)/聚碳酸亚丙酯(PPC)复合材料为壁材,制备毒死蜱微胶囊。[方法]以聚乙烯醇(PVA)-1788为连续相,采用乳化-溶剂挥发法制备微胶囊,利用激光粒度分析仪测定微胶囊粒径,通过光学显微镜对微胶囊形貌进行表征,高效液相色谱法(HPLC)测定微胶囊的包封率、载药量及缓释性能。[结果]经PMMA共混改性后的PPC载体微胶囊,平均粒径为7.15μm,经测载药量为27.56%,包封率为83.77%,对毒死蜱的缓释效应优于单纯以PPC为壁材的微胶囊,缓释期为33 d。[结论]2种聚合物共混改性后的微胶囊在降解性、缓释期上克服了以单一聚合物为壁材的缺点,载药量、包封率也较高。     

靶向性紫杉醇纳米胶束的制备及体外评价

为了增加紫杉醇溶解度和稳定性,采用薄膜分散法制备紫杉醇纳米胶束;采用粒径测定仪测定粒径和PDI;采用UV法测定药物的含量,计算载药量和包封率;采用膜透析法对载药聚合物胶束的体外释药进行考察。本研究制备的纳米胶束粒径分布均匀,平均粒径为(64.34±1.83)nm,包封率大于85%;紫杉醇纳米胶束体外释放显示了良好的缓释特性。本研究制备的紫杉醇纳米胶束制备工艺操作简单,制备得到载药胶束的粒径较小且分布均匀,包封率、载药量较高。     

氧化石墨烯对盐酸四环素的缓释性能研究

本文以氧化石墨烯为药物载体,承载盐酸四环素,探究不同的载药量、pH值、温度的装载率和缓释性能。结果表明,氧化石墨烯的载药率为81.5%,包封率为16.3%。且在pH为5的条件下药物缓释性能最佳,24小时后累计释放率为72.89%;在一定温度范围内,温度越高其药物累积释放率越多。当温度为60℃时,8小时后药物累计释放率为58.59%。     

载阿霉素聚乳酸多孔微球的表征及释药性能

以阿霉素（DOX）为小分子化学药物模型,采用吸附法对聚乳酸（poly-L-lactide,PLLA）多孔微球进行载药,采用场发射扫描电子显微镜（FE-SEM）、傅里叶变换红外光谱（FTIR）、X射线衍射（XRPD）及差示扫描量热（DSC）对DOX-PLLA复合微球的形貌粒径及空气动力学性能、药物及材料的理化性能、载药性能进行表征,并且研究了其载药量、包封率和体外释放性能。结果表明,不同载药量之间的PLLA多孔微球粒径并无显著差异,均具有良好的空气动力学性能,适合肺部可吸入给药的条件;化学组成未见明显改变,物理结构由结晶态变为无定形态;随载药量的增加（2.9%,4.0%,4.6%）,包封率逐渐降低（56%,51%,44%）;药物的体外释放与原料药相比具有一定的缓释效果,最长释放时间可达5天,表明DOX-PLLA复合微球有望作为缓释制剂用于肺部给药。     

阿维菌素凝胶微球制备及其缓释性能研究

以壳聚糖(CS)和海藻酸钠(ALG)为包封材料,以阿维菌素(AVM)为芯材,采用锐孔法制备了阿维菌素-海藻酸钠-壳聚糖微球,考察了海藻酸钠质量分数、壳聚糖质量分数、氯化钙质量分数和芯壁体积比(质量分数1%的阿维菌素乳液与质量分数3%海藻酸钠溶液的体积比)对微球形态及包埋率的影响,利用SEM、FTIR等对微球结构及性质进行了表征,并考察了其在土壤中的缓释性能和释药机制。结果表明,经优化的制备条件为:海藻酸钠、壳聚糖及氯化钙的质量分数分别为3%、0.6%及5%,芯壁体积比为1∶2,制备的载药微球形状规整,成球性良好,粒径约0.7 mm,载药量31.65%,包埋率83.81%;红外光谱分析显示,芯壁材料之间除氢键外,没有发生化学作用。所制备的阿维菌素微球在土壤中具有缓释特性,42 h累积释药率达到82.06%,之后药物释放减缓。药物释放特性符合Riger-Peppas模型,释放机理为Fick扩散。     

5-氟尿嘧啶/明胶纳米载药微球的制备及体外性能研究

目的：以5-氟尿嘧啶(5-FU)为模型药物,明胶为载体材料,制备5-氟尿嘧啶/明胶纳米载药微球,探究药物的缓释效果和抗肿瘤性能。方法：“单凝聚相法”制备明胶纳米载药微球;透射电镜（TEM）和粒径分析仪（DLS）分析纳米微球的形貌、粒径分布情况;计算其包封率和载药量,并对其体外缓释效果和抗肿瘤性能进行研究。结果：明胶纳米微球的表面形态良好,分散均一,平均粒径65.1?2.1 nm,明胶纳米微球的包封率为23.5?1.9 %,载药量为69.7?0.5 %;明胶微球具有良好的缓释性能,Higuchi方程对微球的体外药物释放情况拟合度较高。四甲基偶氮唑蓝实验结果表明,5-FU/明胶微球对胃癌细胞(SGC7901)具有明显的抑制作用。结论：5-FU/明胶微球缓释性好,抗肿瘤活性显著,可作为抗癌药物的缓释制剂。     

Synthesis of pH-responsive isolated soy protein/carboxymethyl chitosan microspheres for sustained pesticide release

In order to improve the utilization rate of avermectin (AVM), a complex was prepared by electrostatic self-assembly using isolated soy protein (ISP) and carboxymethyl chitosan (CMCS) for loading AVM to obtain ISP/CMCS@AVM microspheres. The encapsulation efficiency (EE), sustained release property, ultraviolet (UV) protective ability, and toxicity of the microspheres were evaluated, and the release kinetics of AVM from the microsphere at different pHs were investigated. The results demonstrated that the average particle size of ISP/CMCS@AVM was 283.95 nm, and the EE reached 88.42% for AVM after denaturation. After 70 h of exposure to UV light, the residual rate of AVM in ISP/CMCS@AVM was 78.12%, which was significantly higher than 35.18% in the AVM emulsion. Moreover, the formulation imparted pH sensitivity and sustained-release property to AVM and was consistent with the Korsmeyer–Peppas model, controlled by Fick diffusion. Finally, the insecticidal toxicity of ISP/CMCS@AVM did not differ significantly from that of unmodified AVM. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48358.     

半纤维素基阿维菌素载药微囊的制备及性能

目前阿维菌素以高效性、无污染和低抗药性等特点而得到广泛应用，但是其稳定性较差，易降解导致使用量较大从而造成浪费。为解决上述问题，本文以半纤维素为基体，利用原位聚合法制备阿维菌素载药微囊（HDCM），通过制备条件、热降解性、储存稳定性和释放动力学研究，确定了HDCM的载药量、热稳定性及释放性能。结果表明，在芯壁比为1∶34（质量比），温度为65℃，pH为3.5的制备条件下，HDCM的载药量可达66.5%，粒径较小且分散均匀。HDCM的热降解性能和恒温热稳定性能较阿维菌素原药有所提高，最高热分解温度从261℃增加到272℃，阿维菌素原药10h后降解率达到12.1%，而载药量为66.5%的HDCM降解率仅为5.2%。HDCM的释放机理满足Fick扩散，阿维菌素原药在水中的累积释放率在12h之内达到83.8%，而HDCM的累积释放率在24h之后才有所增大，12h内其释放率仅为33.7%，表明HDCM具有极好的缓释性能。     

Comparative study of encapsulated vildagliptin microparticles produced by spray drying and solvent evaporation technique

Vildagliptin (VLG), an antihyperglycemic drug, having high water solubility and shorter elimination half-life. This leads to administer VLG frequently to maintain its therapeutic efficacy. Hence the goal of this work was to formulate sustained release polymeric VLG microparticles by spray drying technique using 3² full factorial design (Design-Expert Software). Ethyl cellulose (EC) and span-80 were used as encapsulating material and surfactant, respectively. This work furthermore assessed the probability of encapsulating VLG by single emulsion oil in oil (o/o) solvent evaporation technique. The resultant microparticles from these two methods were evaluated to demonstrate the significant differences in their particle size, percentage yield, drug loading (DL), encapsulation efficiency (EE), in vitro drug release, surface morphology, and drug–polymer compatibility. EE of microparticles prepared by spray drying and solvent evaporation technique was in the range of 71.42–89.87% and 51.79–64.03%, respectively. The in vitro drug release study from the microparticles prepared by both methods was conducted for 12?h. Microparticles prepared by solvent evaporation technique showed incomplete VLG release in 12?h. To visualize the effects of independent factors (polymer and surfactant amount) on dependent factors (EE and DL), 2D contour and 3D surface plots were constructed. Significant variations in microparticles’ physicochemical properties were observed with two formulation techniques. Optimum EE and sustained drug release of VLG–EC microparticles were conclusive using spray drying and solvent evaporation techniques.     

Elaboration of a feather keratin/carboxymethyl cellulose complex exhibiting pH sensitivity for sustained pesticide release

Feather keratin (FK) and carboxymethyl cellulose (CMC) were used as raw materials to prepare a FK/CMC polyelectrolyte complex via electrostatic interactions. Using avermectin (AVM) as a model drug and elevated temperature, an FK/CMC@AVM drug-carrying complex was obtained. The structure and morphology of FK/CMC@AVM were both analyzed by Fourier transform infrared spectroscopy, dynamic light scattering, and scanning electron microscopy (SEM). Furthermore, the encapsulation efficiency, anti-ultraviolet, sustained release, and toxicity properties of FK/CMC@AVM were studied. The results showed that the average particle size of FK/CMC@AVM was 386.57 nm and the encapsulation efficiency was 67.06%. Under UV light irradiation, FK/CMC@AVM significantly improved the stability of AVM and the half-life of AVM was found to be delayed from 354 to 1800 min. Moreover, the sustained release of AVM featured pH sensitivity and was consistent with the Korsmeyer–Peppas model. Upon increasing the pH from 1.5 to 9.5, the release mechanism of AVM changed from Fick diffusion to non-Fick diffusion. Finally, the toxicity characteristics of FK/CMC@AVM were not significantly different from those of nonmodified AVM. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47160.     

炭气凝胶对阿维菌素的控释性能研究

文章首次采用炭气凝胶作为控释载体对阿维菌素进行控释性能研究。利用蒸发溶剂法和反溶剂法将阿维菌素包埋到多孔的炭气凝胶载体内,并利用紫外分光光度计和药物溶出实验对其整体的载药量和载药后的缓释性能进行了分析。结果表明:反溶剂法和蒸发溶剂法制备的阿维菌素-炭气凝胶控释剂有较高的载药量,达24.24%,控制释放时间可长达25 h以上。炭气凝胶有望成为新一代药物控释载体。     

Production and evaluation of vildagliptin-loaded poly(dl-lactide) and poly(dl-lactide-glycolide) micro-/nanoparticles: Response surface methodology approach

A laboratory scale spray dryer was used to encapsulate vildagliptin (VLG), an antihyperglycemic drug, into different polymers such as poly(dl-lactide) (PDLA), poly(dl-lactide-glycolide)-50:50 (PLGA 50:50), and poly(dl-lactide-glycolide)-75:25 (PLGA 75:25). Response surface methodology (RSM) was employed to evaluate the effects of process and formulation factors on the encapsulation efficiency (EE). The physicochemical properties of the drug-loaded micro-/nanoparticles, mainly the drug loading (DL), particle size distribution, surface morphology, drug–polymer compatibility, and release rate were investigated. % EE of drug-loaded micro-/nanoparticles were in the range of 57.10% to 76.44%. PLGA50:50 micro-/nanoparticles showed highest EE as compared to PDLA and PLGA75:25 micro-/nanoparticles. The mean particle size of the micro-/nanoparticles containing PLGA 50:50, PLGA 75:25, and PDLA polymers were 428?nm, 640?nm, and 1.22 µm, respectively. Surface morphology study revealed smooth, spherical and nonporous surface structures of the micro-/nanoparticles. Fourier transform infrared spectroscopy studies confirmed the drug–polymer compatibility. Powder X-ray diffraction analysis of micro-/nanoparticles revealed that VLG was present in the amorphous form within the micro-/nanoparticles formulations. In vitro release study demonstrated that VLG is slowly released from micro-/nanoparticles for 12?h and the drug release rate was influenced by type and viscosity of polymers used. This work suggests that PDLA, PLGA 50:50, and PLGA75:25 polymers are able to sustain the VLG release rates from micro-/nanoparticles.     

Avermectin/polyacrylate nanoparticles: preparation,characterization, anti-UV and sustained release properties

In an effort to reduce the dose of drugs and in order to improve drug efficacy, avermectin (AVM) was encapsulated by amphipathic polyacrylic ester (PAE) via self-assembly. The experimental results indicated that the AVM/PAE nanoparticles were spherical in shape, homogeneous dispersion, and had a core-shell structure, the particle size ranged from 172.7?nm to 337.8?nm, the highest encapsulation efficiency and loading capacity were 62.11 and 25.65%. The anti-UV property has been significantly improved. Consistent with the Korsmeyer–Peppas model, the release rate was observed to be higher upon decreasing Tg and increasing the core-shell ratio.