海藻酸钠-壳聚糖-粉末活性炭生物微胶囊的制备

制备了海藻酸钠-壳聚糖-粉末活性炭(SA-CA-PAC)微胶囊,研究了添加适量粉末活性炭后对新型SA-CA-PAC生物微胶囊的粒径、机械强度和膨胀度等主要性能的影响.结果表明:适量粉末活性炭的添加对海藻酸钙胶珠和SA-CA-PAC微胶囊其它制备条件的影响不大,但却对SA-CA-PAC微胶囊的机械强度性能有较大的影响.在反应温度为30℃时,向2.0%的海藻酸钠溶液中添加粉末活性炭量为0.75%,氯化钙溶液浓度为4.0%,壳聚糖溶液浓度1.8%,成膜反应时间10 min,覆膜时间10 min,液化时间8 min,控制盐离子浓度为1.5%,所制得的SA-CA-PAC微胶囊具有良好的成囊性能.扫描电镜结果显示,SA-CA-PAC微胶囊具有良好的膜结构.     

壳聚糖在药物微胶囊方面的应用

药物微胶囊是近些年来发展出来的新型剂型，在微胶囊的壁材方面壳聚糖由于其优良的韧性、细胞亲和性等优点，日益引起人们的关注，本文就壳聚糖在药物微胶囊方面的应用做了简单介绍。     

海藻酸钙-几丁聚糖微胶囊的形态与粒径

以静电法通过高压成型装置制备了海藻酸钙-几丁聚糖微胶囊,重点考察了海藻酸钠浓度、凝胶化时间、成膜前冲洗液的种类、几丁聚糖溶液的pH值对微囊形态与粒径的影响.实验结果表明,与生理盐水、甘露醇及直接成膜相比,成膜前采用蒸馏水冲洗胶珠制备出的微囊大小均匀、表面光洁、球形度好;几丁聚糖溶液pH值对微囊形态,甚至膜强度有很大的影响,应根据实际应用需要选取适当的pH值,初步探讨了微囊的控制释放性能.     

纳米TiO2修饰壳聚糖/石蜡相变微胶囊的制备与性能研究

以36℃相变石蜡为芯材,天然高分子壳聚糖为壁材,纳米二氧化钛(TiO₂)修饰壳体,利用乳化交联法制备了具有抗紫外功能性的相变微胶囊。探讨了不同因素对微胶囊性能的影响,经实验优化,当乳化剂用量为10%,油水相比例为3∶1,纳米TiO₂添加量为0.12g时,制得的相变微胶囊包覆率可达81.61%。通过扫描电镜、差示扫描量热仪、热重分析仪和紫外-可见分光光度计等分析,结果表明相变微胶囊表面光滑、形态规整,相变潜热为118.90J/g,具有良好的热循环和热稳定性,以及紫外屏蔽功能性。     

壳聚糖-海藻酸钠载药微球的缓释性能研究

采用滴球法制备了壳聚糖-海藻酸钠载四环素微球,考察了原料浓度配比、四环素投药量、添加戊二醛、滴球体积和壳聚糖分子量对微球的影响,并利用紫外分光光度计测试了载药微球在PBS溶液中1h、5h、1d、2d、5d、10d时的药物释放.结果表明,以8.5×104 Da壳聚糖为原料、壳聚糖与海藻酸钠的浓度比为1.2:1、未添加戊二醛、并用大针管滴定的实验组拥有比较理想的缓释性能和良好的生物相容性.     

种子包衣壳聚糖膜性能的研究

探讨了不同酸溶液（柠檬酸、乳酸、盐酸和硝酸）壳聚糖制成的包衣膜对氧气及二氧化碳的透过性能和对油菜种子发芽的影响。研究表明，温度和压力对不同壳聚糖包衣膜的气体透过系数有明显影响；不同酸溶液／壳聚糖制成的包衣膜对气体透过分离性能有明显差别，因而直接影响到种子的发芽率与幼苗生长等各项生理与生化指标；无机酸溶液（盐酸和硝酸）／壳聚糖制成的包衣膜更利于种子发芽。     

聚乙烯醇-海藻酸钠-壳聚糖共混膜的制备与性能

采用溶液共混法制备了不同配比的聚乙烯醇-海藻酸钠共混膜和聚乙烯醇-海藻酸钠-壳聚糖共混膜。通过FT-IR、TG、SEM及力学性能等测试对共混膜进行了分析和表征。结果表明共混膜中聚乙烯醇、海藻酸钠及壳聚糖三组分之间存在强烈的相互作用和良好的相容性,三者共混明显改善了纯聚合物和二元膜的性能。     

海藻酸钠/壳聚糖复合纸的制备及性能研究

目的研究海藻酸钠/壳聚糖对纸张的增强作用及制得复合纸对色素及金属离子的等温吸附特性,实现海藻酸钠/壳聚糖在纸张中的复合应用。方法依次采用阴离子多糖海藻酸钠、阳离子多糖壳聚糖季铵盐对纤维素滤纸进行浸渍干燥处理。结果相比滤纸基材,复合纸的抗张强度提高了119%,耐破度提高了105%。红外检测显示,复合纸的氢键吸收峰变宽、变高,说明材料中的氢键结合力变强。吸附等温线拟合显示,制得的复合纸对甲基橙色素具有较好的吸收性能。对Cu2+的吸附符合Langmuir及Freundlich模型方程,属于单分子层吸附。结论海藻酸钠/壳聚糖可用于制备具有一定吸附性能的复合纸,并能增强其力学性能。     

静电喷雾法制备羧甲基纤维素/壳聚糖液芯微胶囊

以羧甲基纤维素(CMC)和壳聚糖(CS)聚合物为原料,采用静电喷雾技术制备了CMC/CS液芯微胶囊。研究了制备条件对微胶囊成型和尺寸的影响,并用激光扫描共聚焦显微镜、扫描电子显微镜和倒置显微镜进行了表征。将四环素与CMC溶液共混,以Al3+-CS作为凝固浴,在电压10 kV、液面距离20 mm、流速10 mL/h的条件下,制备了载药微胶囊。微胶囊的药物包封率随壳聚糖浓度增大而提高,在1.5%时达到99.5%。药物释放实验结果表明CMC/CS液芯微胶囊的释放率与pH有关,控释性能良好。     

壳聚糖脱乙酰度对海藻酸钠/壳聚糖微胶囊的表面性质及蛋白吸附的影响

采用流动电势技术、 接触角技术及表面轮廓技术分别考察了由不同脱乙酰度壳聚糖制备的海藻酸钠/壳聚糖(ACA)膜的表面电荷分布、 表面亲疏水性、 表面粗糙度, 并以纤维蛋白原为模型, 采用静态吸附实验技术考察了表面性质对蛋白在ACA微胶囊表面的吸附量及吸附构象的影响。结果表明, ACA微胶囊表面净电荷为负, 表面正电荷随脱乙酰度的降低而减少。由脱乙酰度60%~90%壳聚糖制备的ACA膜的表面接触角均为70°左右, 且无显著性差异。ACA微胶囊表面呈颗粒状结构, 表面粗糙度随壳聚糖脱乙酰度的降低而减小。蛋白吸附分析表明, "棒状"的纤维蛋白原分子以"侧向"和"直立" 2种形式吸附于ACA微胶囊表面。当壳聚糖脱乙酰度较低时, 蛋白吸附量较小, 且此时蛋白多以"直立"形式吸附。以上结果表明, 由壳聚糖脱乙酰度带来的ACA微胶囊表面性质差异不仅影响了蛋白吸附量, 而且影响了蛋白吸附方式。      

壳聚糖超滤膜的研究

以壳聚糖为原料，2％乙酸为溶剂，选择适当的膜液组成和制备条件，可以制得截留分子量为67000的超滤膜．该膜对0．1％牛血清蛋白的截留率可达90％以上．研究了铸膜液组成和若干因素对膜性能的影响．     

Preparation of N,O-carboxymethyl chitosan coated alginate microcapsules and their application to Bifidobacterium longum BIOMA 5920

In order to greatly improve vitality of probiotic bacteria within the application, a novel biocompatible vehicle, N,O-carboxymethyl chitosan (NOCs) with appropriate degrees of substitution coat alginate (ALg) microparticles, was prepared by electrostatic droplet generation. The amount of chitosan (Cs) and N,O-carboxymethyl chitosan (NOCs) coated on the ALg microparticles was determined by differential scanning calorimetry. The surface morphology of ALg microparticles, Cs coated ALg microparticles and NOCs coated ALg microparticles was determined using scanning electron microscopy. The coating thickness of Cs coated ALg microparticles and that of NOCs coated ALg microparticles was directly observed with confocal laser scanning microscopy. In order to assess pH sensitivity of microparticles, the bovine serum albumin release from the microspheres was tested in acid solution (pH 2.0) for 2 h and subsequently in alkaline solution (pH 7.0) for 2 h. The survival of Bifidobacterium longum BIOMA 5920 loaded in NOCs coated with ALg microparticle was improved in simulated gastric juice (pH 2.0, for 2 h) compared to that of B. longum BIOMA 5920 loaded in ALg microparticles and Cs coated ALg microparticles. After incubation in simulated intestinal juices (pH 7.0, 2 h), the release of microencapsulated B. longum BIOMA 5920 was investigated.     

海藻酸钙/聚精氨酸微胶囊的制备及其生物相容性

以海藻酸盐、 聚精氨酸为壁材, 采用高压静电法制备了球形度好、 表面光洁、 粒径均匀的新型药物载体——海藻酸钙/聚精氨酸微胶囊。参照医疗器械生物学评价标准, 对其生物相容性进行了研究。细胞毒性试验结果显示, 当海藻酸钙/聚精氨酸微胶囊的含量为0.1、 0.5、 1.0 mg/mL时, 微胶囊对L929细胞生长无明显抑制作用, 海藻酸钙/聚精氨酸微胶囊浸提产物在10.0 mg/mL时仍无细胞毒性作用。海藻酸钙/聚精氨酸微胶囊不引起急性全身毒性反应, 不引起溶血反应。通过本组试验可见, 采用高压静电法制备的药物载体——海藻酸钙/聚精氨酸微胶囊具有较好的生物相容性, 具有开发和应用价值。     

作为药物载体的壳聚糖/氧化石墨烯中空微胶囊的制备

采用层层自组装法,以氧化硅微球为模板制备了壳聚糖(CS)/氧化石墨烯(GO)微球,去核后成功地制备了CS/GO中空微胶囊。研究了组装次数、壳聚糖浓度和交联剂京尼平对微球及中空微胶囊形貌的影响,并以布洛芬为药物模型研究了CS/GO中空微胶囊的载药性能及药物缓释性能。实验结果表明,CS/GO中空微胶囊具有完整的中空结构,粒径在760nm左右。增加包裹层数和提高包裹溶液中的壳聚糖浓度都可以增加囊壁的厚度。经交联处理后,CS/GO微胶囊的囊壁更加致密和完整,其对布洛芬的载药率从19%提高至72%,释药时间从10h延长至60h。     

Mucoadhesive alginate/poly (L-lysine)/thiolated alginate microcapsules for oral delivery of Lactobacillus salivarius 29

In this study, thiolated alginate was synthesized by introduction of cysteine to alginate to prepare mucoadhesive alginate/poly (L-lysine)/thiolated alginate (APTA) microcapsules for efficient oral delivery of Lactobacillus salivarius 29 (LS29), a novel therapeutic Lactobacillus strain, in vitro and in vivo. About 759 +/- 32.4 microM of cysteine per gram of alginate was introduced by estimation of Ellman's reagent reaction. LS29-loaded APTA microcapsules provided suitable morphology, size, and a high loading content and efficiency. LS29 in LS29-loaded APTA microcapsules were effectively protected from simulated gastric condition (pH 2.0) than that of unprotected LS29. LS29 were released from APTA microcapsules in simulated intestinal condition (pH 7.2) with a time-dependent manner. The in vitro and in vivo mucoadhesion study suggested that APTA microcapsules had remarkably stronger mucoadhesive property and provided a promising delivery system for oral administration of LS29.     

Magnetic N-succinyl chitosan/alginate beads for carbamazepine delivery

Context: Epilepsy is a chronic condition characterized by recurrent unprovoked seizures. The most optimal use of drugs was limited due to their widespread systemic and central side effects. In contrast, focal drug delivery to epileptogenic focus based on superparamagnetic carrier is considered to be a promising and safe alternative. This delivery system could arrive exactly at the targeted tissue and deliver the loaded drug there with the help of an external magnetic field. Objective: A new magnetic delivery system was established to inhibit paradoxical discharge once the onset of seizures. Materials and methods: Carbamazepine was incorporated into N-succinyl chitosan (NSC)/alginate hydrogel beads by ionic interaction. The characteristics of the beads including morphology, release behavior, and magnetic property were also investigated. Results: Acceptable spherical morphology, excellent slow-release property, and superparamagnetic property of the NSC/alginate hydrogel beads were observed. Discussion and conclusion: The magnetic NSC/alginate beads may be acted as a sustained-release formulation. The drugs exhibit the potential magnetic property owing to Fe3O4 particles. It is promising that the released drugs are induced by the weak magnetic field of epileptogenic zone and have the potential of locating them so as to inhibit paradoxical discharge once the onset of seizures.     

不同条件对SA/GT/CS三元复合水凝胶微球溶胀性能的影响

将海藻酸钠/明胶共混液滴入舍有CaCl2的壳聚糖醋酸溶液中,制备出SA/CS/GT三元复合水凝胶微球.改变sA/GT的质量配比、盐离子浓度、温度,考察不同条件下对复合微球溶胀度的影响.结果表明:当SA : GT质量比为10:0.6、10:0.8,CaCl2浓度为3%～4 %,所成微球的溶胀性能较好;随温度的升高,溶胀度不断增大.