2,4-D/CMC接枝物纳米粒子的制备与缓释性能研究

以羧甲基纤维素钠(CMC)为基材,甲基丙烯酸甲酯(MMA)和二甲基二烯丙基氯化铵(DMDAAC)为改性单体,通过乳液聚合制备了CMC-g-P(MMA-DMDAAC)共聚物,采用自组装方法负载2,4-二氯苯氧乙酸(2,4-D)得到2,4-D/CMC-g-P(MMA-DMDAAC)纳米药物缓释体系。利用傅里叶红外光谱(FTIR)、差示扫描量热法(DSC)、热重分析(TGA)、扫描电镜(SEM)、粒度分析仪对其结构和形貌进行表征,并探究其载药性能和缓释性能。结果表明,2,4-D/CMC-g-P(MMA-DMDAAC)载药粒子呈笼状结构,粒度分布为160～425 nm;其载药率随着CMC∶MMA∶DMDAAC的摩尔比增大而提高,最高可达40.8%;其药物累计释放率随CMC∶MMA∶DMDAAC的摩尔比增大而降低,其释放行为符合Weibull模型,遵循Fick扩散机理。     

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。     

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。     

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。     

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。     

壳聚糖-海藻酸钠载药微球的缓释性能研究

采用乳化交联法制备出负载5-氟尿嘧啶(5-Fu)的壳聚糖-海藻酸钠磁性载药微球。利用红外(FIRT)、X射线衍射(XRD)、热重(TG)、紫外-可见分光光度计(UV)对1其进行结构表征和缓释性能研究,考察了不同因素对载药微球缓释性能的影响。结果表明,油水相体积比为1∶1时载药性能最佳,载药量为6.69%,包封率为22.00%,产物发生交联反应且保持原有晶型,同时在不同p H值环境下载药微球相对5-Fu药物有明显的缓释作用,并且在p H=8.4时药物达到最大释放量,微球适用于给肠癌细胞靶向供药。     

低CMC纳米载体PEGMA-b-PLLA-b-PCL的制备及其药物缓释性能

以ε-己内酯（ε-CL）为疏水原料，聚乙二醇甲醚甲基丙烯酸酯（PEGMA）为亲水原料，通过引入亲疏水性过渡原料L-丙交酯（LLA），利用可逆加成-断裂链转移法（RAFT）制备了超低临界胶束浓度（CMC）的聚乙二醇甲醚甲基丙烯酸酯-聚丙交酯-聚己内酯（PEGMA-b-PLLA-b-PCL）。通过FTIR、1HNMR、GPC、DLS和SEM对聚合物的结构、相对分子质量（简称分子量）及粒径进行测定，用界面张力法测得PEGMA-b-PLLA-b-PCL 胶束溶液的CMC，用溶剂挥发法负载姜黄素（CUR）制备载药胶束溶液，并计算其载药量和包封率，进一步考察载药胶束溶液在不同环境下的释药能力。结果表明，聚合物相对分子质量（简称分子量）为1220~8782，粒径为28~180 nm，且最低CMC为0.62 μg/mL（pH=7.4）。载药胶束的载药量和包封率最高可达12.6%和78 .0% (pH=7.4)，且药物释放可在15 d内完成，在pH=5环境下释放量最高可达45.53%。     

大蒜素/海藻酸钠/明胶/壳聚糖复合微球的制备及性能

以大蒜素为模型药物,采用复凝聚法制备了海藻酸钠/明胶/壳聚糖复合微球,考察了不同条件对微球溶胀性、载药性能和缓释性能等指标的影响。结果表明,明胶和海藻酸钠(质量比为1∶3)为2%,大蒜素投入量与混合胶比为1∶2时,制备的载药微球(DSGCM)外形规则,粒径分布在0.8~0.9mm之间,载药量为24.3%,包封率为69.4%,复合微球具有p H敏感性,在p H=7.4介质中微球溶胀率达到450%,药物释放过程符合Higuchi方程,明胶的加入可以延缓DSGCM复合微球的药物释放性能。     

盐酸米托蒽醌多囊脂质体的制备工艺优化及性能

采用均匀设计优化并制备了平均粒径为58.75 μm的载盐酸米托蒽醌多囊脂质体。该多囊脂质体粒度分布较窄,球形度好。Zeta电位、相变温度及稳定性考察均表明该体系稳定性强,适于药物的释放体系。渗漏率结果表明相对于室温（37 ℃）,冰箱（4 ℃）更有利于载药多囊脂质体的保存。盐酸米托蒽醌平均包封率为90.13%,考察了胆固醇及三油酸甘油酯用量对多囊脂质体药物释放的影响,药物释放符合《药典》规定,无突释效应,且具有较好的体外缓释性能。     

2,4-Dichlorophenol molecularly imprinted two-dimensional photonic crystal hydrogels

A novel molecularly imprinted two-dimensional (2-D) photonic crystal hydrogels (MIPH) for sensitive and label-free recognition of 2,4-dichlorophenol (2,4-DCP) was prepared. The 2-D photonic crystal template was fabricated by using air-water interface self-assembly method. And then the template was embedded with molecularly imprinted polymer, which was synthesized with 2,4-DCP as imprinted molecules, dimethyl sulfoxide as solvent, acrylic acid and acrylamide as functional monomers, N,N-methylene bis acrylamide as cross-linker, azobisisobutyronitrile as initiator. The imprinted molecules were removed by 0.01 M ammonia solution. The results indicated that the 2,4-DCP molecularly imprinted 2-D photonic crystal hydrogels has good response and recognition ability to 2,4-DCP. When the molar ratio of cross-linking density of MIPH is 2.3% and the molar ratio of imprinting molecule is 5.0%, the change of Debye ring diameter is the largest. The diameter of Debye ring increased by 7.1 mm when the concentration of 2,4-DCP changed from 0 to 1 × 10⁻⁶ M, and the particle spacing of MIPH reduced 38 nm. In addition, the diameter of the Debye ring hardly changed in the solution of analogues of 2,4-DCP such as, phenol, 2-chlorophenol, 2,4,6-trichlorophenol and so on, indicating that the MIPH has highly sensitivity and specificity.     

Optimization of an herbicide release from ethylcellulose microspheres

Summary The herbicide 2,4-D was microencapsulated using ethyl cellulose to develop controlled release formulations that protect it from photodegradation and evaporation and to reduce the environment pollution. Ethyl cellulose microspheres loaded with 2,4-D were prepared by the emulsion solvent-evaporation technique. We have obtained the desired microspheres with higher drug entrapment and encapsulation yield by varying certain conditions as stirring speed, polymer-solvent ratio, drug-polymer ratio, pH of continuous phase and organic phase solvent. The shape and size of microspheres were analysed by scanning electron microscopy. The herbicide release was studied at 25 °C and the release data were analysed according to Fick’s Law. The results demonstrate that we can control the release rate by modifying the process parameters.     

红光响应眼镜蛇神经毒素PEG-PLGA纳米囊的制备与表征

以聚乙二醇-聚乳酸-聚乙醇酸嵌段共聚物(PEG-PLGA)为囊材,添加脱镁叶绿酸作为光敏剂,采用复乳法制备了光响应的眼镜蛇神经毒素纳米囊。以纳米囊的包封率、载药量和粒径为指标,采用单因素法对纳米囊的制备条件进行优化;以差示量热扫描分析其热流变性能,并以累积释药量研究其光控释行为。优化的PEGPLGA、眼镜蛇神经毒素及光敏剂脱镁叶绿酸质量配比为40∶12.5∶1,获得的纳米囊包封率为72.3%±3.6%,载药量为15.1%±1.3%,平均粒径为(862±23)nm,电位为(-46.5±3.8)m V,呈紧密球形,光敏剂分布在囊壳;在650 nm半导体激光照射30 min,体外释放明显加快。该纳米囊在不光照时具有增强药物稳定和缓释作用,而红光可促进药物释放,因而可实现光控靶向。     

Core content and stability of n‐octadecane‐containing polyurea microencapsules produced by interfacial polymerization

Microencapsulation of phase change material (PCM) n‐octadecane was carried out by interfacial polymerization technique using core and bulk monomers as toluene‐2,4‐diisocyanate (TDI) and diethylene triamine (DETA), respectively. Cyclohexane was used as the solvent for TDI and n‐octadecane, which formed the oil phase. The effect of encapsulation procedure, core‐to‐monomer ratio (CM ratio) and PCM‐to‐cyclohexane (PC) ratio was investigated on core content, encapsulation efficiency, and stability of microcapsules. Using a modified procedure, the core content was found to increase with the increasing CM ratio and reached a maximum at 3.7, while the encapsulation efficiency continuously decreased with the increasing CM ratio. Also the encapsulation efficiency was found to have a strong dependence on PC ratio and a maximum encapsulation efficiency of 92%, along with the core content of 70% was obtained with CM ratio of 3.7 along with the PC ratio of 6. The microcapsules were well shaped, i.e., round and regular, with narrow size distribution at these conditions. The PCM microcapsules were found to be stable to heat treatment at 150°C for 8 h. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

磺化硅胶催化合成2,4-滴丁酯

以2,4-二氯苯氧乙酸和正丁醇为原料,磺化硅胶为催化剂,催化合成除草剂2,4-二氯苯氧乙酸正丁酯(2,4-滴丁酯)。考察催化剂用量、原料配比及回流时间对反应的影响。结果表明,最佳反应条件为:催化剂用量为2,4-二氯苯氧乙酸质量的1.4%,n(正丁醇):n(2,4-二氯苯氧乙酸)=10:1,回流时间为1.0 h,2,4-二氯苯氧乙酸正丁酯的收率为98.7%。     

A novel one-step microemulsion method for preparation of quercetin encapsulated poly(methyl methacrylate) nanoparticles

A series of drug-loaded poly(methyl methacrylate) (PMMA) nanoparticles were prepared and studied as controlled release carrier of quercetin drug using a simple one-step differential microemulsion method. The polymer carriers were prepared in different monomer/surfactant ratios. The encapsulated PMMA nanoparticles were characterized by Fourier transform infrared spectroscopy, dynamic light scattering and transmission electron microscopy analysis. The particle size was obtained below 10 nm with spherical shape and narrow size distribution. In vitro drug release studies were performed using a dissolution medium such as sodium phosphate buffer saline simulating body fluids. Based on a full factorial 3² experimental design, nine formulations for quercetin-loaded PMMA nanoparticles were prepared and the molar ratio of monomer/surfactant and amount of initiator were considered as independent variables, while the encapsulation efficiency, solid content and drug release were taken into account as responses. Based on ANOVA analysis, with desirability factor of 0.952, the software F3 was suggested as an optimized formulation. This formulation was composed using a monomer/surfactant molar ratio of 3 and initiator amount of 0.02 g as independent variables, while the amounts of 71.10, 25.34, and 61.54%, in the order given, for encapsulation efficiency, solid content and drug release, were obtained as responses. To estimate release mechanism, the obtained cumulative release data were fitted to zero-order, first-order, Higuchi and Korsmeyer-Peppas kinetic models. In vitro release experiments in all cases revealed that the controlled release behavior followed from Korsmeyer-Peppas kinetic model exhibited non-Fickian diffusion mechanism. Consequently, this research offers useful pharmaceutical carriers with the purpose of providing prolonged release for targeting delivery.     

脱氧氟尿苷脂质体的制备

目的建立脱氧氟尿苷(DFUR)脂质体的制备工艺。方法采用逆向蒸发法制备DFUR脂质体,并以包封率为参考指标,进行正交试验优化该脂质体的配方。以优化的配方制备脂质体,观察其微观形态,测定粒径、包封率及稳定性,并进行体外释药实验。结果制备DFUR脂质体的最佳配方为:卵磷脂/胆固醇(摩尔比)为2∶1,有机相/水相(体积比)为5∶1,DFUR浓度为2mg/ml,磷酸盐缓冲液pH值为7.0。以此配方制备,脂质体包封率可达52.15%。3批DFUR混悬液,粒径小于220nm的粒子比率均在70%以上,显微镜下观察可见,脂质体呈球形或椭圆形,粒径范围在0.15μm～1.00μm之间。4℃保存49d,脂质体的稳定性良好。其累积释放率远低于原料药浓度。结论已建立了DFUR脂质体的制备工艺,该工艺操作简便可靠,所需设备简单,稳定性较好,可用于包埋水溶性药物。     

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.     

乳化-溶剂挥发法制备乙基纤维素/萘普生复合微球

以乙基纤维素（EC）为载体材料,萘普生为包埋药物,采用O/W型乳化-溶剂挥发法制备了包封率较高的EC/萘普生复合载药微球,利用正交试验优化制备工艺,得出当EC与萘普生的质量比为3：1,EC用量2.5%,聚乙烯醇用量0.8%,吐温-80用量0.4%时是复合微球的最佳制备工艺,在该工艺条件下药物包封率达到88.97%。通过扫描电子显微镜（SEM）、激光粒度分析、傅里叶变换红外光谱（FT-IR）对复合微球的形态和结构进行了分析表征。SEM显示复合微球的形态顺滑,激光粒度分析表明复合微球平均粒径为14.014μm,复合微球的FT-IR谱图中既有EC的特征峰,又有萘普生的特征峰,但没有新基团产生,表明EC包覆萘普生过程中未产生新化合物。体外释放实验表明复合微球的累积释药率随溶出介质pH值的增大而增大,在溶出介质pH值为9时,复合微球的累积释药率最大,达到82.5%,缓释性能较好。