Preparation and characterization of PDLLA/chondroitin sulfate /chitosan scaffold for peripheral nerve regeneration

A novel bioactive and bioresorbable PDLLA/chondroitin sulfate/chitosan scaffold was prepared via layer-by-layer（LBL） electrostatic-self-assembly （ESA） and the thermally induced phase separation （TIPS） technique. Chondroitin sulfate and chitosan were alternately deposited on the activated PDLLA substrate. The deposition process was monitored by UV-Vis absorbance spectroscopy. After frozen and lyophilized, the scaffold was characterized by attenuated total reflection （ATR）-FT-IR, XPS, SEM and AFM. The results showed that the scaffold was modified uniformly with a dense inner layer with few detectable pores and a porous sponge outer layer with the pore size about 5 μm, there was an obvious across section and the average thickness of each layer was about 9.4 nm.     

Preparation and Charactcrization of a Novel PDLLA/Chondroitin Sulfate/Chitosan Asymmetry Film

A novel bioactive and bioresorbable asymmetry film was prepared,The PDLLA membrane was activated by 1,6-hexanediamine to obtain a stable positive charge surface.Chondroitin sulfate and chitosan were then deposited on activated PDLLA membrane via layer-by-layer(LBL)electro-static assembly (ESA)technique.The deposition process was monitored by UV-Vis absorbance spectroscopy.The composite membrane was frozen lyophilized to form the asymmetry film and characterized by attenuated total reflectic (ATR)-FT-IR,XPS and SEM.The experimental results show that a stable 1,6-hexanediamme layer on PDLLA substrate based on the aminolysis of the polyester and the layer thickness increase linearly first with the increase of the deposited layers,and then increases slowly due to the layer interpenetration.The test results of ATR-FT- IR and SEM show the asymmetry film is modified uniformly with a dense inner layer and a porous sponge outer layer.     

Preparation and Characterization of a Novel PDLLA/ Chondroitin Sulfate/Chitosan Asymmetry Film

A novel bioactive and bioresorbable asymmetry film was prepared. The PDLLA membrane was activated by 1, 6-hexanediamine to obtain a stable positive charge surface. Chondroitin sulfate and chitosan were then deposited on activated PDLLA membrane via layer-by-layer （LBL） electro-static assembly （ESA） technique. The deposition process was monitored by UV-Vis absorbance spectroscopy. The composite membrane was frozen lyophilized to form the asymmetry film and characterized by attenuated total reflectic （ATR）-FT-IR, XPS and SEM. The experimental results show that a stable 1, 6-hexanediamine layer on PDLLA substrate based on the aminolysis of the polyester and the layer thickness increase linearly first with the increase of the deposited layers, and then increases slowly due to the layer interpenetration. The test results of ATR-FT- IR and SEM show the asymmetry film is modified uniformly with a dense inner layer and a porous sponge outer tayer.     

硫酸软骨素钙的制备工艺

本研究以硫酸软骨素钠为原料 ,将其溶液进行离子交换 ,生成硫酸软骨素酸 ,然后用氯化钙溶液洗脱 ,无水乙醇沉淀 ,即生成硫酸软骨素钙 ,同时对其各项指标进行了检测 ,并通过正交试验优化了工艺条件     

鳐鱼软骨制备硫酸软骨素的研究

文章以鳐鱼软骨为原料,采用稀碱和酶解相结合的方法提取硫酸软骨素。综合考察各种影响因素,设计了正交实验,得出最佳工艺条件。实验表明,鳐鱼软骨提取硫酸软骨素的纯度为90.7%,收率为21.70%。     

鳐鱼软骨制备硫酸软骨素的研究

文章以鳐鱼软骨为原料,采用稀碱和酶解相结合的方法提取硫酸软骨素.综合考察各种影响因素,设计了正交实验,得出最佳工艺条件.实验表明,鳐鱼软骨提取硫酸软骨素的纯度为90.7%,收率为21.70%.     

硫酸软骨素生产新工艺的研究

制备硫酸软骨素新工艺利用双酶酶解法提取。设计了正交试验，得到最优化反应条件。最优反应条件为温度50℃，pH8．6-8．9，加酶量0．03g／d1，收率达17．84％。     

PDLLA/CS/CHS多层膜的制备及影响因素研究

利用静电自组装技术制备聚乳酸/硫酸软骨素/壳聚糖(PDLLA/CS/CHS)多层膜,并对组装影响因素进行研究.用紫外-可见吸收光谱对PDLLA/CS/CHS多层膜在组装过程中的时间、温度、溶液浓度和pH值等影响因素进行分析研究.结果表明自组装复合材料制备的最佳条件为:CS的浓度为2 mg/mL、CHS的浓度为1%(g/mL),组装时间为30 min,温度为30 ℃,溶液pH值为3.8.根据紫外光谱拟定的最佳组装条件组装了多层膜,用扫描电镜观察了多层膜的表面形貌,结果表明自组装膜是一种具有多孔结构的不对称复合膜.     

PDLLA/HA/FK506复合神经导管的制备及体外降解性能

以聚乳酸（PDLLA）为基材、纳米羟基磷灰石（HA）为添加剂、加入免疫抑制剂FK506，用溶剂挥发法制备PDLLA／HA/FK506复合神经导管。通过观察复合导管在磷酸缓冲溶液中降解时pH值变化、质量损耗及材料微观形貌，研究了该复合导管的体外降解性能。结果表明：加入适量纳米羟基磷灰石可以改善聚乳酸降解的酸性问题并提高其力学强度。免疫抑制剂FK506的加入对导管材料的降解性能有一定的影响。PDLLA/HA／FK506复合神经导管具有良好的降解性能。     

壳聚糖/聚乳酸复合超细纤维支架的制备与表征

采用电纺丝技术制备了壳聚糖/聚乳酸复合超细纤维支架。通过扫描电镜（SEM）对纤维的形貌进行了观察,发现随着复合纤维中聚乳酸含量的增加,纤维的平均直径在增大。对所制得的纤维支架的孔隙率、拉伸性能及亲水性进行了测试。制得的纤维支架在组织工程领域拥有潜在应用价值。     

季铵化两亲性壳聚糖衍生物的制备和表征

以天然壳聚糖(CTS)为原料,在壳聚糖结构单元2位-NH2上引入亲水基团-CH2COOH,6位-CH2OH引入疏水基团-CH2CH2N(CH2CH3)2,合成新型季铵化两亲性壳聚糖衍生物.通过紫外可见光谱(UV)、红外光谱(IR)、核磁共振氢谱(1HNMR)和热失重(TG)法对其进行表征与分析.结果表明,所合成的产物为N-羧甲基-O-二乙胺基乙基-壳聚糖(DEAE-CMC).     

Preparation and Evaluation of an Injectable Chitosan-Hyaluronic Acid hydrogel for Peripheral Nerve Regeneration

The aim of this study was to obtain the fillers in the lumen of hollow nerve conduits(NCs) to improve the microenvironment of nerve regeneration. A p H-induced injectable chitosan(CS)-hyaluronic acid(HA) hydrogel for nerve growth factor(NGF) sustained release was developed. Its properties were characterized by gelation time, FT-IR, SEM, in vitro swelling and degradation. Furthermore, the in vitro NGF release profiles and cell biocompatibility were also investigated. The experimental results show that the CS-HA aqueous solution can undergo a rapid gelation 3 minutes after its environmental p H is changed to 7.4. The CSHA hydrogel has interconnected channels with a controllable pore diameter and with a porosity of about 80%. It has a favorable swelling behavior and can be degraded by about 70% within 8 weeks in vitro and is suitable for NGF release. The CS-HA/NGF hydrogel exhibits a lower cytotoxicity and is in favor of the adhesion and proliferation of the BMMSCs cells. It is indicated that the CS-HA/NGF will be a promising candidate for neural tissue engineering.     

利福平壳聚糖的制备及性能研究

选择生物相容性好，可生物降解的壳聚糖为药物载体，并通过体外释放试验和体外抗菌试验，从载体的自身结构和释药过程的两个方面，对其结构进行了测定和分析。结果表明，所合成的利福平壳聚糖体系；具有一定缓释性能，符合临床使用要求，可作为新型缓释药物临床应用。     

胺化磁性壳聚糖的微波制备及其吸附性能研究

以二乙烯三胺为胺化剂,优化了微波法制备胺化磁性壳聚糖的条件及产品对Cu2＋的吸附条件。微波制备胺化磁性壳聚糖的条件为：磁性壳聚糖0.30g,质量分数45%NaOH,氯乙酸5.80g,羧甲基化温度45℃,羧甲基化时间2h,二乙烯三胺9ml,胺化温度65℃,胺化时间2h。产品在pH6.0、吸附时间5h的条件下,对Cu2＋的吸附容量达到112.67 mg.g-1。与传统水浴法相比,微波法反应效率高,所得吸附剂吸附容量提高了近一倍,且有良好的再生使用性.     

半乳糖基化壳聚糖材料的合成与表征

半乳糖是肝细胞表面去唾液酸糖蛋白受体的特异性配体，是肝靶向基团，具有诱导和提高肝细胞在细胞外基质支架材料上的黏附性能。以壳聚糖为基体材料，在EIX2和NHS的活化作用下，将半乳糖基引入到壳聚糖的结构中，合成和制备出新型肝靶向支架材料——半乳糖基化壳聚糖，并通过FTIR、^1HNMR、XRD对其合成产物进行表征，其结果表明：制备的半乳糖基化壳聚糖材料，其半乳糖基的取代度约为11．62％、结晶度较壳聚糖低的一种新型肝组织工程支架材料。     

基于壳聚糖的磁性吸附水凝胶微球的制备与表征

通过原位共沉淀法制备了含有Fe₃O₄纳米粒子的埃洛石纳米管（HNTs）/壳聚糖（CS）磁性复合水凝胶微球,并对产物的形貌和结构进行了表征。引入纳米Fe₃O₄后,Fe₃O₄@HNTs/CS微球成型快且球形度好,在溶液中可通过磁场快速分离。扫描电子显微镜表明Fe₃O₄@HNTs/CS微球具有三维多孔结构。以亚甲基蓝（MB）、刚果红（CR）为模型染料,研究了Fe₃O₄@HNTs/CS对带有不同电荷的离子型染料的吸附性能。结果表明Fe₃O₄@HNTs/CS可吸附MB、CR染料分子。Fe₃O₄@HNTs/CS对CR染料的脱色率可达98%;当HNTs含量为CS质量的40%时,MB脱色率是不含HNTs微球的12倍。研究结果表明:吸附机理主要基于微球和染料分子的静电相互作用;Fe₃O₄@HNTs/CS内部电荷分布独特,能吸附阴离子染料和阳离子染料,磁性则使其更易分离回收。     

水溶性N-酰化壳聚糖的合成与表征

利用马来酸酐和邻苯二甲酸酐在均相条件下与壳聚糖发生N 酰化反应,制备了一系列水溶的N 酰化壳聚糖。用红外光谱和紫外光谱对其结构进行了表征,并根据IR图中的特征吸收峰和UV谱图中强吸收波长变化验证了产物结构。研究了反应物摩尔比对产物的水溶性的影响。     

用于纺织品整理的低分子质量纳米壳聚糖的制备与表征

利用壳聚糖与三聚磷酸钠(STTP)间的离子凝胶原理制备了纳米壳聚糖的分散体系,该分散体系含有与织物或纤维交联的柠檬酸和催化剂次亚磷酸钠等,可直接用于织物的功能整理。讨论了三聚磷酸钠浓度、柠檬酸(CA)浓度、Tween-80用量、温度和pH值等对纳米壳聚糖粒径分布的影响。确定了制备工艺。测试结果表明:所制备的分散体系中,纳米粒子的平均粒径小于20 nm。傅里叶红外光谱的分析表明,磷酸盐已经连接到了氨基位点上,即有效制备了纳米壳聚糖。     

壳聚糖季铵盐的制备及其抗菌性

用壳聚糖与碘甲烷、氢氧化钠直接合成了N-碘化三甲基壳聚糖季铵盐(TMCI),合成路线简单,成本低。对其抗菌性能的研究结果表明,该壳聚糖季铵盐具有良好的水溶性,抗菌性能优于羧甲基壳聚糖,对金黄色葡萄球菌最小抑菌浓度(MIC)为1.0 mg.mL-1,对大肠杆菌和白色念珠菌的最小抑菌浓度为1.25 mg.mL-1。