新型胺基壳聚糖树脂的合成及其对胆红素吸附性能的研究

以壳聚糖为原料，经羟丙基氯化、胺基化，制备了一种新型胺基壳聚糖树脂，研究了该树脂对胆红素的吸附性能。结果表明：胺基壳聚糖树脂的胺基含量比壳聚糖高，该树脂对游离胆红素的吸附在3h基本达到平衡，吸附量随着胺基含量增加而增加，树脂的吸附性能受温度、离子强度影响。胺基壳聚糖树脂对血清白蛋白结合胆红素的吸附量大于壳聚糖，但低于对游离胆红素的吸附。     

磁性交联壳聚糖微球对Cu2+的吸附性能研究

以Fe_3O_4为磁核,环氧氯丙烷为交联剂,制备磁性交联壳聚糖微球(MCB)。采用FTIR、XRD及SEM对MCB进行表征分析,结果表明壳聚糖发生了交联反应,且Fe_3O_4被壳聚糖包埋。通过正交试验L_9(3~4),得到MCB的最优制备工艺条件为:环氧氯丙烷用量为3.0 mL,反应温度为45℃,反应时间为3.0 h,MCB对Cu~(2+)的吸附率可达63.70%。同时在单组分体系中研究了MCB对Cu~(2+)的吸附行为,结果表明:MCB对Cu~(2+)的最佳吸附pH值为5.0,MCB对Cu~(2+)的吸附遵循Langmuir等温吸附模型;动力学研究表明,MCB对Cu~(2+)的吸附过程符合拟二级吸附动力学方程。     

离子凝聚法制备负载流感疫苗的壳聚糖微球

采用三聚磷酸钠(TPP)作为离子交联剂, 应用离子凝聚法制备负载流感疫苗的壳聚糖微球. 筛选出壳聚糖起始质量分数为1%. TPP的浓度对壳聚糖微球的制备影响较大, 采用低浓度的TPP(200 μg/mL)制备的微球放置过夜均出现沉淀现象, 高浓度的TPP(800 μg/mL)在制备过程中出现絮状沉淀. 固化比影响微球的释放行为, 固化比为1∶1的微球爆炸式释放率达到90％, 固化比为1∶3的微球6 h后逐步释放, 12 h后释放率达到95％. 固化比为1∶5的微球6 h后没有明显的释放行为. 壳聚糖溶液的pH对微球的制备和释放没有显著的影响. 通过对负载流感疫苗的壳聚糖微球的制备条件和释放行为的研究结果表明, pH=5.6的壳聚糖溶液, 固化比为1∶3, TPP的质量浓度为400 μg/mL是较理想的流感疫苗壳聚糖微球的制备条件.     

微流控法制备的多孔微球对Cr(Ⅵ)的吸附性能

利用玻璃毛细管搭建单级微流控装置制备单分散水包油（O/W）乳液,以乳液为模板,紫外光照射乳液引发自由基聚合,成功制备了单分散甲基丙烯酸甲酯/甲基丙烯酸二甲基氨基乙酯（MMA/DMAEMA）多孔微球。微球粒径偏差系数（CV）值小于5%,单分散性良好。研究了MMA/DMAEMA多孔微球对Cr(Ⅵ)的吸附性能、再生吸附性能、吸附机理。结果表明：pH对微球吸附Cr(Ⅵ)的量有较大影响,当pH=3时,微球对Cr(Ⅵ)吸附率达到52.9%;循环4次后微球吸附率基本不降低,循环性能好;微球吸附符合准二级动力学模型,属于化学吸附;微球等温吸附符合Langmuir模型,属于单分子层吸附。     

壳聚糖微球用于LHRH拮抗剂类似物缓释体系的研究

研究壳聚糖微球对促黄体生成激素释放激素（ＬＨＲＨ）拮抗剂类似物（ＴＸ４６）的吸附与释放，考察了影响吸附与释放的因素，得到了各种不同微球对ＴＸ４６的吸附与释放平衡曲线，为ＬＨＲＨ拮抗剂用于生育控制及其它临床应用提供了初步的实验依据。     

磁性壳聚糖硅胶复合微球的制备及其吸附Cu~(2+)的性能研究

以壳聚糖与正硅酸四乙酯为原料,采用溶胶-凝胶法,用戊二醛辅助交联合成了磁性壳聚糖硅胶复合微球。通过红外光谱、扫描电镜、X-射线衍射等方法对磁性壳聚糖硅胶复合微球的形态和组成特性进行分析,制备的磁性复合微球中壳聚糖与硅胶材料复合均匀,材料粒径均一,机械强度较高。考察了制备的磁性壳聚糖硅胶复合微球对Cu~(2+)的吸附性能,结果表明微球对Cu~(2+)具有较好的吸附性能,吸附容量达到98.7mg/g。     

壳交联pH响应型PLGA载药微球的制备与研究

首先采用一次乳化法制备出PLGA[聚(乳酸-羟基乙酸)]纳米微球,并通过静电吸附将阳离子聚合物壳聚糖修饰到PLGA微球表面,然后以香草醛为交联剂对壳聚糖进行化学交联,得到一种壳交联的p H响应型纳米微球(PCV),微球粒径为(277.60±38.01)nm,表面电位为(21.60±4.51)m V.微球稳定性评价结果显示微球在24 h内粒径变化较小;流式细胞仪检测显示细胞对PCV微球的摄取量比未经修饰的PLGA微球的摄取量高;空白微球细胞毒性实验表明在空白微球浓度小于80μg/m L时细胞的存活率达93.24%.以多西他赛(DTX)为模型药物进行包载,该纳米微球DTX的载药率为7.48%,包封率为34.98%;体外药物释放实验显示,该微球在p H=5.0环境下孵育90 h的药物积累释放率达58.66%,而在p H=7.4的环境下的药物积累释放率为50.63%;此外,载DTX微球毒性试验结果表明该载药微球对A549肺癌细胞有较强的杀伤作用,其IC50值可达0.0009μg/m L.     

磁性壳聚糖微球的制备及对Cr(Ⅵ)的吸附性能研究

用壳聚糖包埋磁流体,用戊二醛交联制成磁性壳聚糖微球,并用红外光谱表征其结构。用制备的磁性壳聚糖微球吸附Cr(Ⅵ)离子,考察了其对Cr(Ⅵ)离子的吸附性能;探讨了吸附时间、溶液pH值、吸附剂用量、温度、Cr(Ⅵ)起始浓度以及其他离子存在对Cr(Ⅵ)离子去除率的影响。实验结果表明,磁性壳聚糖微球吸附Cr(Ⅵ)离子的最佳条件为:吸附平衡时间40 min,最佳吸附pH值6左右,磁性壳聚糖微球用量10 mg,温度升高有利于提高磁性壳聚糖微球的吸附效率,Cr(Ⅵ)离子起始质量浓度为12μg/mL,无机盐的存在引起磁性壳聚糖微球的吸附性能降低。并且考察了吸附剂的再生性能,实验结果表明磁性壳聚糖微球具有良好的重复使用性。     

单宁微球对Cr（Ⅵ）的吸附性能

利用单宁微球吸附Cr（Ⅵ）,探讨了温度、pH值、Cr（Ⅵ）初始质量浓度等因素对单宁微球吸附性能的影响,并分析了其吸附等温曲线。结果表明,单宁微球对Cr（Ⅵ）具有很好的吸附效果,吸附量可达到45.5 mg/g。单宁微球对Cr（Ⅵ）的去除率随吸附时间的延长而增大,5 h后基本达到平衡。温度对单宁微球吸附Cr（Ⅵ）的影响比较...     

茶多酚锰-壳聚糖微球的制备、控释和诱导肝癌细胞凋亡的研究

选用壳聚糖为微米粒包被材料, 制备茶多酚锰(Tea Polyphenol Manganese, TPMn)-壳聚糖微球. 用荧光显微技术研究了TPMn-壳聚糖微球的荧光特性, 用扫描和透射电子显微镜证实TPMn-壳聚糖微球尺寸和分布规律. RP-HPLC定量分析TPMn-壳聚糖微球包封率为68%, 符合微米级微粒控释药物包封率的要求. 动力学研究结果表明, 茶多酚(TP)-壳聚糖和TPMn-壳聚糖的微球均有控释TP的能力, 控释时间高达40 h以上, 但前者释放速率稍快于后者. TPMn和TPMn-壳聚糖微球均能诱导肝癌细胞凋亡, 但TPMn-壳聚糖微球诱导肿瘤细胞的凋亡速率稍高于TPM. 实验结果证实, 以TPMn-壳聚糖微球方式控释TPMn有利于提高诱导肿瘤细胞凋亡速率. TPMn-壳聚糖微球具有研发成注射型抗肿瘤新药的可能性.     

The Preparation of Functionalized Crosslinked Macroporous Chitosan Microspheres and their Adsorption Properties for Bilirubin

Summary: glutaraldehyde cross-linked macroporous chitosan microspheres (CS) were prepared by inverse phase suspension reaction with sugar as porogenic agent. The microspheres were modified with different reagents of 1, 6 hexanediamine (HDA) and low generation polyamidoamine (PAMAM) dendrimers including PAMAM G1.0, PAMAM G2.0, PAMAM G3.0. The content of amino groups on CS, CS-PAMAM G1.0, CS-PAMAM G2.0, CS-PAMAM G3.0, CS-HDA was 3.56, 5.10, 5.47, 6.47, 4.66 mmol/g, respectively. The bilirubin adsorption on the above five microspheres was carried out in 0.05M phosphate buffer solution (pH = 7.2–7.4) at 37 °C. The results indicated all the modified CS microspheres were better than unmodified CS microspheres for bilirubin adsorption. CS-HDA has the best adsorption property even if the content of the amino groups was not very high.     

染料壳聚糖微球的制备及其对牛血清白蛋白(BSA)吸附性能的研究

采用反相悬浮交联法制备壳聚糖微球,对微球进行羟丙基氯化及氨基化,并偶联色素配体Cibacron Blue F3GA,得到一种新型染料亲和吸附剂.以牛血清白蛋白(BSA)为目标蛋白,考察了该染料亲和吸附剂的吸附性能,发现其对BSA有较高的吸附量(95.2mg/g),吸附行为满足Langmuir吸附等温式.负载牛血清白蛋白的微球容易洗脱,洗脱率高达99％.     

染料壳聚糖微球的制备及其对人血清白蛋白吸附性能研究

人血清白蛋白(Human Serum Albumin,HSA)是血浆中含量最丰富的蛋白质,约占血浆总蛋白的60%.在人体内,HSA有许多重要的生理功能[1],临床上广泛应用于手术输血和危重病人补液,治疗创伤休克、烧伤、水肿和低白蛋白血症等,而且能增强人体抵抗能力,是迄今为止产量最大、临床用量最大     

PAMAM树状大分子对酮基布洛芬溶解度的影响

以酮洛芬为模型药物,研究聚酰胺-胺(PAMAM)树状大分子对酮洛芬的增溶作用,并探讨其作用机理.采用紫外光谱法测定了G1.0、G1.5、G2.0、G2.5、G3.0、G3.5PAMAM在不同浓度和不同pH时对酮洛芬的增溶量.并运用计算机模拟方法对PAMAM与酮洛芬相互作用的机理进行了探讨.实验结果表明,酮洛芬的溶解度随溶液pH值变化而变化,在pH4.0～6.0范围内,PAMAM树状大分子对酮洛芬的增溶量随着PAMAM的代数、浓度和溶液pH的增加而增大.整代和半代都具有增溶作用.然而,在同一pH条件下,对于具有相同官能团数目的整代和半代,整代增溶效果要高于半代.计算机模拟结果表明PAMAM与酮洛芬主要靠静电作用力结合.增溶机理可能是酮洛芬的羧基与PAMAM的伯胺和叔胺发生静电作用.     

A spheres-in-sphere structure for improving protein-loading poly (lactide-co-glycolide) microspheres

In present study, protein loaded poly (lactide-co-glycolide)/chitosan microspheres (PLGA/CS MSs) with spheres-in-sphere structure were prepared in order to weaken the burst release of protein from PLGA microspheres (PLGA MSs) and to buffer acidic micro-milieu. The PLGA MSs and PLGA/CS MSs were characterized in terms of their size distribution, morphology, drug-loading rate, zeta potential and physical-chemical properties. The incubation experiments of PLGA MSs and PLGA/CS MSs were manipulated in PBS solution at pH 7.4, 37 °C to monitor the release of BSA and the vehicles degradation. The release kinetic of BSA was illuminated mainly based on the degradation processes of the matrices. External CS crusts were proved to strikingly improve the release kinetic of the model protein by reducing initial burst release and extending continuous release while acting as a diffusion barrier. Moreover, using PLGA/CS MSs could avoid the decrease of pH value resulted from the acidic products of PLGA MSs because of the effective buffer action of the basic groups in CS. The results demonstrated that the spheres-in-sphere structure is an effective way to control the initial burst release of protein and to overcome the acidic problem of protein-loading PLGA MSs.     

放射标记法研究壳聚糖与牛血清白蛋白的自组装超薄膜

基片在两种带有相反电荷的聚电解质溶液中交替吸附 ,其表面形成致密有序的超薄膜的自组装 (ＥＳＡ ｅｌｅｃｔｒｏｓｔａｔｉｃｓｅｌｆ ａｓｓｅｍｂｌｙ)技术是由Ｄｅｃｈｅｒ及其合作者在 1 991年提出[1] ,由于简单易行 ,从一出现就受到了广大研究者的极大兴趣[2～ 4 ] .对生物材料来说 ,这无疑是一项非常重要且方便的表面改性手段 .因为生物材料在生物体内种植时 ,是否会被机体视为异物 ,关键在于机体与材料表面的相互作用 ,而与材料的本体性质基本无关[5] .因此利用这种技术 ,可对生物材料 ,特别是对那些生物相容性不好的材料表面进行…     

γ-irradiated chitosan-polyvinyl pyrrolidone hydrogels as pH-sensitive protein delivery system

The effects of pH of the buffer solution and the composition of the hydrogel system on the bovine serum albumin (BSA) adsorption capacity of chitosan (CS)–polyvinyl pyrrolidone (PVP) (CSPVP) hydrogels and release of BSA were investigated. Poly-electrolyte CSPVP hydrogels with different compositions were prepared by irradiating CS/PVP/water mixtures with γ-rays at ambient temperature. The adsorption capacity of hydrogels was found to increase from 0 to 350 mg BSA/g dry gel, by changing external stimuli and hydrogel composition. The adsorption of BSA within CSPVP hydrogels increased with increase in CS content in the hydrogels. When the irradiation doses of hydrogel increased, the adsorption of BSA decreased. The maximum adsorption of BSA was observed at pH 5. A significant amount of the adsorbed BSA (up to 95%) was eluted in the phosphate medium containing 0.1 M NaCl at pH 7.4.     

Cationic poly(amidoamine) dendrimers as additives for capillary electroseparation and detection of proteins

We examine the influence of cationic poly(amidoamine) (PAMAM) dendrimers on capillary electroseparation–UV analysis of proteins. PAMAMs adsorbing to the capillary surface suppressed the wall‐adsorption of proteins; meanwhile, PAMAMs added to the buffer exhibited selectivity toward proteins. Presence of 3×10^?4 g/mL PAMAM generation one (G 1.0) in 30 mM phosphate, at pH 2.6, rendered significant enhancement in separation efficiency; the merged peaks of myoglobin and trypsin inhibitor were separated. Moreover, the protein–dendrimer interactions changed the inherent UV absorbance profiles of proteins. UV–Vis study showed that the absorbance of cytochrome C and transferrin increased at the detection wavelength of 214 nm; their detection sensitivity enhanced by 2.44 and 2.01‐folds, respectively, with addition of 5×10^?4 g/mL PAMAM G 1.0.     

Study on elution behavior of poly(amidoamine) dendrimers and their interaction with bovine serum albumin in asymmetrical flow field-flow fractionation

Polyamidoamine (PAMAM) dendrimers have an amine surface and an ethylenediamine core and are of great interest in various applications such as in drug delivery. Physiochemical properties of PAMAM dendrimers vary with pH. At neutral to basic pH, PAMAM dendrimers are either weakly charged or uncharged and tend to adsorb on to the neutral packing material, making chromatographic separation of the dendrimers difficult. Asymmetrical flow field-flow fractionation (AsFlFFF) was tested as an alternative to the chromatographic techniques for separation of the PAMAM dendrimers. AsFlFFF provided generation-based separation of the dendrimers even at neutral and basic pH. The elution time increased gradually as the generation number (and thus the size) increased. Separation of impurities such as generational or missing-arm impurities and aggregates from the main population was also achieved. Electrostatic and hydrophobic interactions (e.g., repulsive elecrostatic interaction among the dendrimer molecules or attractive hydrophobic interaction between the dendrimer molecules and the membrane) may result in an inaccurate size measurement. Careful optimization of experimental conditions such as the flow rate, pH, and the salt concentration may be required to minimize the interactions with the membrane. AsFlFFF was also tested for a study on the interaction between the PAMAM dendrimers and proteins. AsFlFFF was able to show the growth in the size of bovine serum albumin (BSA) when BSA is mixed with increasing amounts of PAMAM dendrimers. Results suggest that, with proper optimization, AsFlFFF could become a useful tool for separation and characterization of large charged molecules such as PAMAM dendrimers.     

胺基化PGMA交联微球对胆红素的吸附机理

通过胺基与环氧键之间的开环反应, 用己二胺及多乙烯多胺等小分子胺化试剂对聚甲基丙烯酸缩水甘油酯(PGMA)交联微球进行了化学改性, 制得了胺基化的PGMA交联微球, 研究了该功能微球对胆红素的吸附特性, 考察了胺化试剂的分子结构、介质pH值、离子强度及温度等因素对其吸附性能的影响, 较深入地研究了吸附机理. 实验结果表明, 胺基化微球对胆红素具有强吸附作用, 吸附容量可达17.80 mg·g-1, 等温吸附服从Freundlich方程. 胺基化微球与胆红素分子之间的作用力以静电相互作用为主, 同时也存在氢键作用与疏水相互作用. 在pH 值为6 的介质中二者之间的静电作用最强, 胆红素吸附容量最高. 高离子强度不利于静电相互作用, 盐度增大使吸附容量减小. 温度升高有利于疏水相互作用而不利于氢键作用, 两种作用中占优势者主导温度对吸附容量的影响. 用己二胺改性的微球, 由于疏水相互作用的强化以及较长连接臂导致较小的空间位阻, 使其对胆红素的吸附能力明显高于多乙烯多胺改性的微球.