聚酰胺微胶囊分散染料的制备及其缓释性能

由对苯二甲酰氯与不同二胺单体采用界面聚合法制备聚酰胺微胶囊分散染料.用扫描电子显微镜测定微胶囊粒径大小及其分布;紫外-可见分光光度计测定微胶囊中染料扩散到丙酮溶液中的吸光度,确定了微胶囊染料在丙酮中的缓释性能.结果表明,随着脂肪烃基的二胺中亚甲基数的增大,聚酰胺微胶囊分散蓝(2BLN)的粒径和粒径分布变宽,在丙酮中的缓释性增强.     

含VE微胶囊的制备及其控制释放性能研究

以天然维生素E（VE）为芯材，利用Shirasu porous glass (SPG) 膜乳化结合液中干燥法，制备了粒径单分散的聚苯乙烯（PS）微胶囊.微胶囊的粒径为膜孔径的4倍，粒径单分散系数CV小于0.2.考察了改变PS和VE的比例及微胶囊的粒径对控制释放性能的影响.     

单细胞微胶囊的制备与表征

基于微流体数字化微喷射技术进行了单细胞微胶囊制备实验,探究了单细胞微胶囊的制备条件和粒径变化规律.结果显示,当微喷嘴的内径及液体的脉冲流动步长小于2倍的细胞最小粒径时,可实现单细胞微胶囊的制备.单细胞微胶囊的平均粒径随着微喷嘴内径的增大而线性增大,可通过改变微喷嘴内径调节单细胞微胶囊的粒径大小.以200μm微喷嘴制备猪...     

硬脂酸丁酯微胶囊的制备与表征

采用原位聚合法用脲醛树脂包覆硬脂酸丁酯,制得相变储热微胶囊.利用激光粒径分布仪、扫描电镜、差示扫描量热仪(DSC)和傅立叶转换红外光谱仪分别研究了微胶囊的粒径分布、表面形态、热性能和壳结构.结果表明,所得微胶囊粒径分布均匀,表面光洁,具有良好的韧性和致密性.不同的制备工艺对微胶囊粒径分布有一定的影响,其中在28 000 r/m in下乳化5 m in时,所得微胶囊的粒径分布集中在1~4μm.DSC测定结果显示硬脂酸丁酯微胶囊的最大相变焓为68 J/g.     

不同相对分子质量羟乙基纤维素对甲维盐微胶囊制备的影响

采用原位聚合法以三聚氰胺-甲醛树脂为壁材制备了甲维盐微胶囊。 探讨了不同黏均相对分子质量羟乙基纤维素作为乳化剂对微胶囊表面形貌、粒径及其分布、包覆率与载药量的影响,对使用不同黏均相对分子质量羟乙基纤维素作为乳化剂制备的微胶囊的释放性能进行了表征。 结果表明,以相对分子质量较小的羟乙基纤维素制备的微胶囊外形规则、致密且无黏连现象。 随羟乙基纤维素黏均相对分子质量的增加所得微胶囊的平均粒径及粒径分布逐渐增大,包覆率与载药量逐渐减小。 释放性能的研究表明,采用相对分子质量较小的羟乙基纤维素制备的微胶囊的释放性能较好。     

配糖蛋白B肠溶微胶囊的研究

采用双乳液法研制配糖蛋白Ｂ的肠溶微胶囊，考察了微胶囊的形态、粒径及其分布，在摸拟肠液的缓冲液中进行溶解释放试验。配制了两种口服微胶囊混悬制剂，并考察了它的稳定性。     

CS/TPP纳米微胶囊的制备及其载药性能

利用离子凝胶法, 以三聚磷酸钠(TPP)为交联剂, 由壳聚糖(CS)制备了CS/TPP纳米微胶囊. 用红外光谱仪、扫描电镜和粒径分析仪进行了表征, 并以牛血清蛋白(BSA)作为模型药物, 考察了所制备的CS/TPP纳米微胶囊的包载和缓释性能. 结果表明, CS/TPP纳米微胶囊的红外光谱相对于CS和TPP的红外光谱发生了很大变化, 说明CS和TPP通过正负电荷吸引聚合成囊; 粒径分析表明, 离子凝胶法可以得到粒径约430 nm的均匀分散的壳聚糖纳米微胶囊, 经冷冻干燥后粒径变为300 nm左右; 微胶囊包封率最高可达79.74%, 模型药物的持续释放时间可达7 d以上.     

NaCl／EC微胶囊释放规律的实验研究

考察了膜厚，粒径，温度及外部溶液性质对ＮａＣｌ／ＥＣ微胶囊释放速率的影响，实验表明对单个微胶囊在膜厚增加，粒径减小，温度下降时则释放速率下降，当外部溶液中尿素浓度增加时也使释放速度下降。     

以聚脲为囊壁薄荷素油微胶囊的制备及表征

采用界面聚合法,以薄荷素油为芯材,以异佛尔酮二异氰酸酯为壁材单体,在催化剂四甲基乙二胺作用下和水反应形成聚脲外壳,制备出了薄荷素油微胶囊.通过扫描电镜、激光粒度分析仪、傅里叶红外光谱仪及热重分析仪分别对香精微胶囊的表面形貌、粒径分布、单体反应情况和热稳定性进行了分析表征.通过紫外可见分光光度计对香精微胶囊包覆率进行了测定.并分析了均质化速率和微胶囊平均粒径的关系以及不同乳化剂种类和芯壁比条件下微胶囊的形貌特征.结果表明,微胶囊平均粒径随均质化速率的增大而减小,下降到1μm左右时趋于平稳,当乳化剂采用聚乙烯醇且芯壁比为4∶1时,微胶囊形貌最佳,为规整球形.最终测得微胶囊芯材包覆率为84.09 wt%,粉末状微胶囊样品含油率为72.64 wt%,并且微胶囊芯材具有良好的热稳定性.     

高效氯氰菊酯微胶囊的制备、表征及释放性能

以高效氯氰菊酯为芯材, 乙基纤维素为壁材, 采用溶剂蒸发法制备了微胶囊, 并对其理化性能进行表征, 通过单因素实验研究了工艺参数对微胶囊外观形貌、 粒径大小及分布、 包封率、 载药量和缓释性能的影响. 结果表明, 乳化剂种类和剪切时间可以显著影响微胶囊的外观形貌; 随着乳化剂用量增大, 微胶囊粒径减小, 分布变窄, 当Tween-80用量从4%增加至8%时, 微胶囊平均粒径从59.9 μm减少到29.8 μm, 跨距也从1.21减少到0.72. 随着芯壁比(质量比)减小, 微胶囊粒径和包封率均逐渐增大, 载药量逐渐减小, 当芯壁比为1:1.75时, 包封率可以达到70%以上. 微胶囊释放动力学模型符合Ritger-Peppas模型(lgQ=lgk+nlgt); 平均粒径相近而载药量不同时, 初期载药量最小的样品释放速率慢, 累积释放率低; 载药量相近而平均粒径不同时, 粒径大的样品释放速率低, 累积释放率也低.     

制备聚电解质空腔胶囊及其荧光蛋白装载

以三聚氰胺甲醛(MF)微粒为模板,采用逐层静电自组装技术交替吸附聚苯乙烯磺酸钠(PSS)和聚烯丙基胺盐酸盐(PAH),得到具有核壳结构的复合式微球,然后通过pH=1的盐酸溶液除去中心模板,得到直径约为3～4μm的空腔胶囊.使用藻红蛋白作为探针分子,通过比较空腔胶囊装载前后荧光强度的变化,发现pH在4～5之间时,胶囊呈现最大的蛋白装载量.pH在6～10的范围内,藻红蛋白在胶囊上的装载量几乎不变.pH3时,装载能力很差.此外,通过荧光共聚焦显微镜对不同pH条件下的蛋白装载规律进行了成像分析.一部分藻红蛋白在pH=4的条件下通过扩散进入了胶囊的内部,而pH=7的条件下,藻红蛋白不进入胶囊内部,而是吸附在表面.     

Core‐shell structure microcapsules with dual pH‐responsive drug release function

We report dual pH‐responsive microcapsules manufactured by combining electrostatic droplets (ESD) and microfluidic droplets (MFD) techniques to produce monodisperse core (alginate)‐shell (chitosan) structure with dual pH‐responsive drug release function. The fabricated core‐shell microcapsules were size controllable by tuning the synthesis parameters of the ESD and MFD systems, and were responsive in both acidic and alkaline environment, We used two model drugs (ampicillin loaded in the chitosan shell and diclofenac loaded in the alginate core) for drug delivery study. The results show that core‐shell structure microcapsules have better drug release efficiency than respective core or shell particles. A biocompatibility test showed that the core‐shell structure microcapsules presented positive cell viability (above 80%) when evaluated by the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay. The results indicate that the synthesized core‐shell microcapsules were a potential candidate of dual‐drug carriers.     

Preparation of chitosan/alginate microcapsules by high-voltage electrostatic method

Chitosan and sodium alginate have the opposite charges; they can become a gelatin by the electrostatic attraction, High-voltage electrostatic droplet generator method was used to prepare chitosan-sodium alginate microcapsule. Multi-layer chitosan-sodium alginate microcapsule was prepared through layer-by-layer self-assembly, and the morphology was investigated. In addition, the release property of ofloxacin in microcapsules was studied by UV-Vis microscopy under different conditions such as pH value, layer number, etc. The results showed that the prepared microcapsules have a smooth surface with average particle size about 100 μm. The result of controlled release indicated that the prepared microcapsules are pH-independent, and the rate of release decreased when the layer number increases.     

三聚氰胺甲醛微球的制备及模板法构建聚谷氨酸基微胶囊

以分散聚合法制备低交联度三聚氰胺甲醛(MF)微球, 研究了pH和反应时间等对MF微球粒径、表面电位和溶解性的影响. 以MF微球为模板, 采用层层自组装法交替吸附聚谷氨酸(PGA)和壳聚糖(CS), 构建中空的PGA/CS微胶囊. 采用偏光显微镜、纳米粒度及电位分析仪、红外和透射电镜等进行表征. 结果表明, MF粒径及表面电位随pH值降低而减小, 在盐酸中的溶解性随反应时间延长而变差. 在自组装过程中, 微球表面电位呈正负交替变化, 表明以静电力为主要驱动力制得的空心微胶囊粒径均匀, 分散良好, 模型药物罗丹明可成功载入其中, 有望成为优良的水溶性药物载体.     

Preparation of protein microcapsules with narrow size distribution by sonochemical method

Protein microcapsules with narrow size distribution have been prepared by sonochemical method which is a simple, fast, environmental friendly and cost-effective method. The prepared microcapsules are composed of a water-insoluble core and an outer protein shell. The hydrophobic drugs could be encapsulated into protein microcapsules directly via sonochemical method by dissolving drugs in the nontoxic and edible vegetable oil before ultrasonication, which is a potential solution for drug resistance by hiding cytotoxic drugs in the carrier and allows for the delivery of high doses in relatively small volume. The size and size distribution of protein microcapsules are very important for their practical application. In this paper, the factors affecting the size and size distribution of protein microcapsules are investigated in detail. Moreover, confocal laser scanning microscopy and transmission electron microscopy confirmed that the protein microcapsules with narrow size distribution were obtained.     

Melting and swelling behaviors of UV-irradiated gelatin gel microcapsules

Gelatin gel microcapsules with a narrow size distribution have been prepared for the use of regenerative therapy by means of SPG (Shirasu porous glass) emulsification and UV-induced cross linking, and the melting and swelling behaviors of the gel membrane of the microcapsules were observed. The gel melting temperature was proportional to the 2/3 power of UV irradiation time t for tor=1 h. The average cross-sectional area of the microcapsules that remains insoluble normalized by that at 25 degrees C monotonically increased with temperature for tor=1 h. Repeated quenching of the gel microcapsules between two temperatures (25 and 40 degrees C) induced a reversible size change, which was attributed to the helix-coil transition of collagen molecules locally. From a theoretical consideration of gel particles, the observed gel melting behavior was explained well, and the scaled volume of the microcapsules was expressed as a function of scaled temperature with four fitting parameters for t相似文献   

Viscoelastic properties of hydrogel microcapsule membranes

The viscoelastic properties of poly(L-lysine-alt-terephthalic acid) (PPL) microcapsules were studied as a function of medium pH. An abrupt increase in the apparent relative viscosity of PPL microcapsule suspensions was observed in the pH range between 4.0 and 7.0 due to the increased total particle volume concentration caused by a sudden increase in microcapsule size. Above pH 7.0, the relative viscosity decreased, being indicative of a deformability of the microcapsules. The adiabatic compressibility of PPL microcapsule membranes was the lowest at pH 4.0 and increased remarkably when the pH value departed from 4.0. On the contrary, the membrane density was the highest at pH 4.0 and decreased as medium pH shifted to either side of this value, implying that the microcapsules behave as compact particles at low pH and loose particles at high pH. The amount of hydrated water also showed a similar change when the pH of the medium was altered.     

复凝聚法制备昆虫激素模拟物十二醇微胶囊及其释放性能

以明胶(GE)和阿拉伯胶(AG)为壁材, 通过复凝聚法将昆虫激素模拟物十二醇(C12OH)包覆在微胶囊中, 改变微胶囊壁材的浓度和交联度, 探讨了体系中C12OH的可控释放性能. 通过对壁材质量比为1及不同pH条件下的壁材凝聚率测试确定最佳复凝聚的pH为4.0; 考察了不同分散剂对微胶囊及其分散液性能的影响, 确定以Tween 20/Span 80(质量比1∶1)作为复凝聚法包覆C12OH体系的分散剂. 在壁材质量分数大于或等于3%条件下制备的微胶囊粒径大于壁材质量分数为2%的微胶囊, 胶囊的载药量和C12OH包覆率明显高于后者. 增加交联剂的用量, 壁材交联度、胶囊的载药量和C12OH包覆率都显著提高. 在相同用量的情况下, 用甲醛作交联剂时得到的微胶囊的交联度比用戊二醛作交联剂时的要低, 但其对C12OH的包覆率更高. 通过扫描电镜对微胶囊进行了分析, 认为GE与AG通过复凝聚能够将C12OH包覆在微胶囊内部. 对胶囊中C12OH在恒温恒湿条件下的释放研究结果表明, 3%与4%壁材含量下1%戊二醛交联的微胶囊和5%壁材含量下4%戊二醛交联的微胶囊中C12OH的释放行为有明显的可控性. 通过调节微胶囊的壁材含量和交联度可以达到昆虫激素可控释放的目的.     

Extraction of Cu<Superscript>2+</Superscript> from aqueous solutions using microcapsules containing ionic liquid [BMIM]PF<Subscript>6</Subscript>

Polysulfone (PSF) microcapsules filled with ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF₆] were successfully prepared via solvent evaporation method. The encapsulation capacity of 38.0% was achieved. Microcapsules showed a spherical, porous honeycomb structure. The size of microcapsules was approximately 110 μm and the thickness was approximately 10 μm. Microcapsules have excellent thermal stability, with a higher thermal degradation onset temperature of 360°C compared to traditional extractant-loaded microcapsules. Microcapsules were used to extract Cu²⁺ from aqueous solutions. The effect of chelator, pH, PSF, and ionic liquid on the extraction rate were studied. When chelator was added in aqueous solutions, and the pH of aqueous solutions was 4.5, the extraction rate of microcapsules reached the maximum value, which was 99.0%. These PSF microcapsules containing [BMIM][PF₆] showed potential ability in the treatment of wastewater.     

Porous microcapsule formation with microsieve emulsification

A simple route is presented to prepare core-shell Eudragit microcapsules through a solvent extraction method with the use of microsieve emulsification. Droplets from a solution of Eudragit FS 30D (a commercial copolymer of poly(methyl acrylate-co-methyl methacrylate-co-methacrylic acid) 7:3:1) and hexadecane in dichloromethane are dispersed into water, using a micro-engineered membrane with well-defined pores, in a cross-flow setting. The dichloromethane is extracted from the droplets, which induces demixing in the droplets, leading to a hexadecane-rich core, and an Eudragit-rich shell. The obtained microcapsules have a narrow size distribution due to the microsieve emulsification process. The capsules have a porous shell as shown by SEM and AFM measurements. Their porosity and pore size is dependent on the ratios of Eudragit and hexadecane in the dispersed phase. At pH 7.1 and above Eudragit (FS 30D) dissolves in water; this pH change is used to release the contents of the microcapsule.