纳米SiO2改性聚乙烯醇超滤膜的研究

以聚乙烯醇(PVA)为基膜材料,聚乙二醇(PEG)为添加剂,通过相转化法制备了纳米SiO2/聚乙烯醇膜。考察了PEG的分子量、纳米SiO2的加入量和PEG加入量对PVA膜性能的影响。结果表明,经纳米SiO2改性的PVA膜的性能有了显著的提高,膜的水通量随着PEG分子量和PEG加入量的增大而增大,随着纳米SiO2加入量的增大而减小。     

表面活性剂对膜乳化法制备载药微球的影响

选用不同的外水相表面活性剂,采用膜乳化法与复乳法结合制备了负载牛血清蛋白的乳酸-羟基乙酸共聚物微球.研究了不同外水相表面活性剂对微球形貌、包封率及体外释放的影响.结果表明,外水相中加入聚乙二醇(PEG 1 000),微球表面比未添加表面活性剂时更光滑,形状规则;加入聚乙烯吡咯烷酮(PVP)与Tween 20后微球形貌变化不大;加入十二烷基硫酸钠(SDS)后制备的微球形貌较差.外水相中加入PEG 1 000,PVP或Tween 20后包封率从未添加表面活性剂时的72.5％分别增大至90.3％,86.8％和75.0％,突释率由12.4％降低至7.5％,9.7％和12.1％,外水相加入SDS后包封率降低至62.3％,突释率增大至16.4％.     

添加剂PVP、PEG对PVDF/PVP(PEG)/DMAc铸膜液扩散性质的影响

采用浸入沉淀相转化和铸膜液光透射测试相结合的方法,考察了添加剂聚乙烯吡咯烷酮(PVP)和聚乙二醇(PEG)对聚偏氟乙烯(PVDF)/ PVP(PEG)/二甲基乙酰胺(DMAc)铸膜液的扩散性质的影响.实验中改变了PVP添加剂的含量和PEG添加剂的分子量.结果表明,PVDF铸膜液浸入沉淀过程初始阶段的溶剂外扩散符合费克扩散定律.无添加剂时体系溶剂的表观扩散系数为52.52×10-6 g·s-1/2,添加5% PVP或PEG20000时其系数分别为17.11和22.53×10-6 g·s-1/2,即添加PVP、PEG使PVDF铸膜液的溶剂外扩散速率下降.同时从光透射实验可知,上述添加剂的加入使非溶剂向内扩散的速率上升.实验表明,溶剂外扩散受控于体系的粘度,非溶剂的向内扩散受控于界面的亲水性.研究还改进了浸入沉淀相转化法的实验方法,克服了原有方法的弊端,有助于获得更多扩散行为信息.     

PVA/PVP共混交联膜对2-甲基四氢呋喃溶液渗透汽化脱水的研究

利用共混交联法将马来酸酐(MAH)加入聚乙烯醇(PVA)和聚乙烯吡咯烷酮(PVP)混合溶液中制备PVA/PVP膜。考察了膜的组成、料液中水质量分数和温度对渗透汽化分离性能的影响。结果表明,在V(PVA)∶V(PVP)=8∶2、水质量分数为3.9%的2-甲基四氢呋喃(2-Me THF)溶液和最佳温度为68℃条件下,渗透通量和分离因子分别可达431.64 g/(m~2·h)和272.96。PVA/PVP膜能有效分离2-Me THF/水溶液。SEM、XRD、接触角、机械强度分析结果表明,交联后的PVA/PVP膜均匀致密,结晶度、水接触角明显降低,机械强度显著增强。     

添加剂对喷雾冷冻干燥MgAl2O4粉体性能的影响

以聚乙烯醇(PVA)和聚乙二醇(PEG)作为添加剂,采用喷雾冷冻干燥技术制备MgAl2O4造粒粉体.通过振实密度测量仪、扫描电镜、万能试验机等设备系统研究了不同PVA和PEG添加量下造粒粉体的流动性、颗粒形貌、粒径分布及颗粒强度等性能.通过粉体成型和烧结过程,分析了造粒粉体性能对素坯密度、微观结构和陶瓷光学质量的影响.结果 表明,添加PVA和PEG造粒粉体制备的素坯在预烧过程可以避免晶界大气孔的生成,有利于通过热等静压处理消除残余气孔.添加PEG样品的气孔尺寸较小,短波范围内的透过率提高.添加3wt％PVA和PEG造粒粉体制备的MgAl2O4透明陶瓷在400 nm波长处的透光率分别为76.3％和77.1％,明显高于无添加剂的样品.     

高压电场强化法制备荷电聚醚酰亚胺纳滤膜及其性能研究

采用一种新颖的方法,以聚醚酰亚胺(PEI)为原料,N-甲基-2-吡咯烷酮(NMP)为溶剂,聚乙烯吡咯烷酮(PVP K30)为添加剂,在高压静电场下采用浸没沉淀相转化法制备出荷电纳滤膜。首先研究了铸膜液组成及成膜条件对膜分离性能的影响。得到最佳制膜条件为:PEI质量分数为22%,静电场强度2 k V,所制备的荷电纳滤膜对聚乙二醇(PEG) 1000的截留率为77. 97%。接下来研究了成膜条件以及铸膜液组成对膜表面切向流动电位(zeta电位)的影响。结果表明,随着静电场强度的升高,zeta电位增大;添加PVP K30浓度过低或过高均导致zeta电位降低,当PVP K30质量分数为6%时,zeta电位最大,为96. 19 m V;添加不同相对分子量的PEG,zeta电位值变化并无明确规律,但添加PEG300、PEG600时,zeta电位值较大,分别为49. 98 m V、41. 51 m V。该研究结果对于进一步开发高性能荷电聚醚酰亚胺纳滤膜具有一定的参考价值。     

亲水性聚偏氟乙烯超滤膜的制备

采用干-湿相转化法研究了聚偏氟乙烯(PVDF)中空纤维超滤膜的制备。选用PVDF为膜材料,N,N-二甲基乙酰胺(DMAc)为溶剂,聚乙烯吡咯烷酮(PVP)和聚乙二醇(PEG)为添加剂,考察了一定条件下PVDF和PVP的百分含量及PEG的分子量对膜孔径、机械性能、水通量及形貌结构的影响,用正交实验设计确定了制膜的最佳配方为:PVP含量14%,PVDF含量18%,PEG分子量为200。此配方下所制备的中空纤维膜圆整度较好,断裂强力为3.2 N,断裂伸长率为70%,泡点为0.43 MPa,平均孔径为0.081μm,纯水通量为178 L/(m~2·h)。     

静电喷雾法制备聚醚砜多孔微球孔隙率的控制研究

采用静电喷雾法制备了聚醚砜(PES)多孔微球,通过加入亲水性聚合物聚乙烯醇(PEG)和聚乙二醇(PVA)来调控PES多孔微球的孔隙率,利用扫描电子显微镜和热失重法分析仪表征了PES多孔微球的形貌和孔隙率。结果表明,加入亲水性聚合物PEG和PVA均能显著提高PES多孔微球的孔隙率,且随着其添加量的增多,孔隙率呈先增大后减小的趋势;PVA对PES多孔微球孔隙率的调控效果优于PEG,当PVA添加量为3%(质量分数,下同)时,PES多孔微球孔隙率达到最高值91.35%。     

表面活性剂对五中孔膜结构和性能的影响

以聚偏氟乙烯(PVDF)-聚甲基丙烯酸甲酯(PMMA)-聚氯乙烯(PVC)为膜材料,考察了聚乙二醇1000(PEG1000)、聚乙烯吡咯烷酮(PVP K30)和吐温80作为添加剂对膜的结构和性能的影响.结果表明,上述添加剂都能增大PVDF-PMMA-PVC铸膜液的粘度,其中以PVPK30作添加剂得到的产物的溶解性及增粘性能最好;粘度的改变直接影响到五孔共混膜结构和性能的改变;对固体质量分数为17%的铸膜液,当PVP K30加入质量分数为6%时制得的中空纤维膜可达较佳性能.     

聚间苯二甲酰间苯二胺平板膜的制备及其性能研究

以聚间苯二甲酰间苯二胺（PMIA）为制膜原料,氯化锂（LiCl）、聚乙二醇（PEG-400）和聚乙烯吡咯烷酮（PVP）为添加剂,通过非溶剂诱导相转化法制备了PMIA平板膜,系统考察了聚合物浓度、添加剂种类和含量对PMIA膜结构和性能的影响。结果表明,聚合物浓度和LiCl含量增加,铸膜液黏度增大,导致膜孔径减小,纯水通量降低。而PEG含量的增加,使得聚合物链呈现舒展状态,膜孔径增大,纯水通量升高,亲水性增强。随着PVP含量的增加,膜的纯水通量先升高后降低,膜的亲水性变差。当PMIA的质量分数为9%,LiCl的质量分数为2.8%,PVP的质量分数为1.2%时,膜的纯水通量高达1421.55 L·m^-2·h^-1·bar^-1,对牛血清蛋白（BSA）的截留率为80%,展现出较高的渗透性,为制备高性能膜材料提供了新的思路。     

Ethylenediamino bridged bis(β‐cyclodextrin)/ poly(DL‐lactic‐co‐glycolic acid) nanoparticles prepared by modified double emulsion method: Effect of polyvinyl alcohol on nanoparticle properties

This study continues long‐standing efforts to develop protein delivery systems based on cyclodextrin‐conjugated polyester in our laboratory. The crude products of ethylenediamino bridged bis(β‐cyclodextrin)‐conjugated poly(DL ‐lactic‐co‐glycolic acid) were used in this study to make full use of unreacted reactant. With bovine serum albumin (BSA) as a model protein, the encapsulation effects (the encapsulation efficiency and particle size) of nanoparticles were similar to those of using pure conjugated products. Besides, a water‐in‐oil‐in‐water emulsification technique was conveniently modified. By adding polyvinyl alcohol (PVA) in the internal aqueous phase, a more stabilized emulsion was formed. Consequently, less PVA (～ 0.05%) was needed in the outer aqueous phase and less PVA (0.14 g/g nanoparticles) remained in the nanoparticles. This modification resulted in improved encapsulation efficiency (～ 89–94%) of BSA and an enlarged particle size (340–390 nm). Furthermore, the burst release of BSA at the 1st day was less pronounced (7–12% of the encapsulated amount) than that of nanoparticles with no PVA added in the internal aqueous phase. Degradation studies using transmission electron microscope and gel permeation chromatography suggested that the mechanism for protein release was mainly through nanoparticles erosion. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

复相乳化法制备聚乳酸/水杨酸钠微囊

以W/O/W复相乳化法,聚乳酸为壁材、水杨酸钠为芯材,制备聚乳酸/水杨酸钠微囊。聚乳酸/水杨酸钠微囊的工艺条件为:水杨酸钠溶液浓度为40 mg/mL,聚乳酸溶液浓度为25mg/mL,聚乙烯醇溶液浓度为2mg/mL,内水相水杨酸钠体积为2mL,油相聚乳酸溶液体积为10mL,外水相聚乙烯醇溶液体积为60mL,即内水相与油相比为1∶5,油相与外水相体积比为1∶6。聚乳酸/水杨酸钠微囊的包封率为75.70%。     

Characterization of molecular interaionic and intraionic crosslinkable sulfonated poly(ether ether ketone‐alt‐benzimidazole) membrane

Lysozyme-loaded polymeric composite microparticles were successfully coprecipitated by solution-enhanced dispersion by supercritical CO₂ (SEDS), starting with a homogeneous organic solvent solution of lysozyme/poly(L -lactide)/poly(ethylene glycol) (lysozyme/PLLA/PEG). The effects of different drug loads (5, 8, and 12% w/w), PLLA Mw (10, 50, 100, and 200 kDa), PEG contents (0, 10, 30, and 50% PEG/(PLLA+PEG) w/w), and PEG Mw (400, 1000, and 4000 kDa) on the surface morphology, particle size, and drug release profile of the resulting composite microparticles were investigated. The results indicate that the size of the microparticles decreased and the rate of drug release increased with an increase in drug load, PEG content, or PEG Mw; the particle size first increased and then decreased with an increase in PLLA Mw, and the drug release was controlled by both particle size and PLLA Mw. The Fourier transform infrared spectrometer analysis and circular dichroism spectra measurement reveal that no significant changes occurred in the molecular structures during the SEDS processing, which is favorable to the production of protein–polymer composite microparticles for a protein drug delivery system. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

重组α-2b干扰素缓释微囊制备工艺及体外释药过程研究

以聚乳酸乙醇酸(PLGA)为囊材,对制备a-2b干扰素缓释微囊的工艺条件进行优化,研究了不同PLGA浓度、搅拌速度和搅拌时间对缓释微囊粒径分布、载药量、包封率和体外释药过程的影响。结果显示,在PLGA浓度为0.7gmL-1,搅拌速度2100rmin-1,搅拌时间4min条件下,制备的微囊平均粒径为2.8721m ,表面平滑、形态规整且不聚集,载药量为3.91%,包封率为85.8%,体外可连续释药10天,没有明显突释效应,释药量达93.3%,符合临床药用标准。     

Controlled release of recombinant human nerve growth factor (rhNGF) from poly[(lactic acid)‐co‐(glycolic acid)] microspheres for the treatment of neurodegenerative disorders

Recombinant human nerve growth factor (rhNGF)/bovine serum albumin‐loaded microspheres were prepared by a water/oil/water emulsion and solvent evaporation technique with some modifications. The microspheres were characterized with respect to encapsulation efficiency, morphological properties and drug release. Using higher protein/polymer ratios in the primary emulsion resulted in higher protein content in the microspheres. The protein encapsulation efficiency increased from 89.1% to 97.5% on adding poly(ethylene glycol) to the inner aqueous phase. The in vitro rhNGF release lasted for more than 5 weeks. The biological activity of released rhNGF was confirmed by PC12 cell culture. The microspheres maintained a sustained release of rhNGF for at least 4 weeks in the basal forebrain as detected by fluorescence‐labeled and indirect immunofluorescent techniques. These results demonstrated the rhNGF‐containing microspheres are an effective means for delivering this molecule into the brain and their use may be a promising strategy in the treatment of neurodegenerative disorders such as Alzheimer's disease. Copyright © 2007 Society of Chemical Industry     

快速膜乳化法制备胸腺法新长效缓释微球

采用快速膜乳化技术结合溶剂蒸发法制备以生物可降解聚乳酸-羟基乙酸(PLGA)为载体的胸腺法新载药微球,考察了PLGA分子量、油相中PLGA和乳化剂浓度、外水相pH值和内水相体积等对微球包埋率和粒径的影响. 结果表明,制备粒径均一的PLGA载药微球的优化条件为：PLGA分子量51 kDa,油相中PLGA和乳化剂浓度为100和10 g/L,内水相体积0.5 mL,外水相pH值为3.5. 该条件下所制载药微球粒径均一性好(Span<0.7),药物包埋率高达80%以上,突释率24 h内低于20%,线性持续稳定释药时间长达30 d.     

快速膜乳化法制备载醋酸曲普瑞林PLGA微球

以生物可降解聚合物聚(乳酸?羟基乙酸)(PLGA)为载体,以160 g/L明胶水溶液为内水相、含500 g/L PLGA的二氯甲烷为油相,采用快速膜乳化和溶剂蒸发法制备了粒径均一的载醋酸曲普瑞林PLGA微球,微球粒径约30 mm,粒径分布系数Span<0.8,醋酸曲普瑞林包埋率达80.12%,药物在磷酸盐缓冲液中释放36 d的释放率为72.60%,体外释放行为良好.     

Poly(L‐histidine)‐chitosan/alginate complex microcapsule as a novel drug delivery agent

Novel poly(L ‐histidine)‐chitosan/alginate complex microcapsules were prepared from biodegradable polymers poly(L ‐histidine) (PLHis) in the presence of chitosan at acetate buffer solution pH 4.6. Microcapsules obtained are spherical and well‐dispersed with a smooth surface and a narrow size distribution. The microcapsules can encapsulate the protein model drug hemoglobin (Hb) efficiently. The results show that the complex microcapsules with low, medium, or high molecular weight of chitosan (0.05%, w/v), the highest encapsulation efficiencies obtained are 91.3%, 85.9%, and 94.2% with loading efficiencies of 47.8%, 44.3%, and 39.7%, respectively. The release profiles indicate that Hb‐loaded microcapsules conform to first‐order release kinetic in whole procedure, and 84.8%, 71.4%, and 87.3% of Hb were released during 72‐h incubation in PBS pH6.8 for microcapsules with low, medium, and high molecular weight chitosan (0.05%, w/v), respectively. The results also indicate that particle size and drug loading efficiency have a significant influence on the release profile and encapsulation efficiency. Our results reveal that the PLHis‐chitosan/alginate complex microcapsules are able to encapsulate and release Hb and are potential carriers for protein drugs. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Dual-responsive release behavior of pH-sensitive PVA/PAAc hydrogels containing temperature-sensitive PVA/PNIPAAm microcapsules

Both temperature and pH responsive drug delivery system was prepared by combining temperature-sensitive poly(vinyl alcohol) (PVA)/poly(N-isopropylacrylamide) (PNIPAAm) microcapsules and pH-sensitive PVA/poly(acrylic acid) (PAAc) hydrogels. The release of drug from the composite hydrogels increased as the pH increased due to the repulsion among the carboxylate anions in the PVA/PAAc hydrogels. The release of drug from the composite hydrogels also increased as the temperature decreased due to the higher hydrophilicity generated below the lower critical solution temperature of PNIPAAm. The compression moduli of composite hydrogels increased with increasing the content of PVA/PNIPAAm microcapsules. The biocompatibility of composite hydrogels was confirmed by the cytotoxicity test.     

Preparation and properties of poly(propylene carbonate maleate) microcapsules for controlled release of pazufloxacin mesilate

A novel biodegradable aliphatic polycarbonate, poly(propylene carbonate maleate) (PPCMA) was synthesized by terpolymerization of carbon dioxide, propylene oxide, and maleic anhydride (MA), using a polymer supported bimetallic complex as catalyst. The utility of PPCMA to encapsulate and control the release of drug pazufloxacin mesilate (PZFX), via microcapsules, was investigated. PPCMA microcapsules containing PZFX were elaborated by solvent evaporation method based on the formation of double W/O/W emulsion. The manufacturing parameters such as the volume ratio of V(PPCMA) : V(PZFX), the concentration of stabilizer gelatin in outer aqueous phase played major roles on microcapsule characters, and were altered to optimize the process parameters. The PPCMA‐PZFX microcapsules were obtained with smooth and spherical surface under optimum condition, the mean diameter of microcapsules was ～ 2 μm, and the drug loading and drug encapsulation efficiency of the microcapsules were 22.9 ± 1.05% and 82.1 ± 2.03%, respectively. PZFX released from PPCMA microcapsules was found to reach 89.8 ± 2.89% after 36d in a pH 7.4 phosphate‐buffered solution, and the release profile obeyed the Higuchi equation. The results suggest that the new polymer PPCMA provides an alternative to degradable matrix polymers for long‐term sustained releasing drug delivery systems. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011