三偏磷酸钠交联壳聚糖膜的制备及其性能研究

将充分溶胀的壳聚糖膜置于一定浓度的三偏磷酸钠溶液中进行交联反应制备出交联壳聚糖膜。用傅立叶变换红外光谱(FT-IR)、X-射线衍射(XRD)和扫描电镜(SEM)表征了其结构,并测试了其吸水率、力学性能和酶降解性能。研究结果表明,交联作用明显提高了膜的抗张强度和抗水性,并有效地降低了溶菌酶对其降解速率。该交联膜有望用作可控降解生物医用材料。     

三偏磷酸钠交联壳聚糖/聚乙烯醇共混膜的制备及其性能研究

将充分溶胀的壳聚糖/聚乙烯醇共混膜置于一定浓度的三偏磷酸钠溶液中进行交联反应制备出交联壳聚糖膜。用红外光谱(FTIR-ATR)、X-射线衍射(XRD)和扫描电镜(SEM)表征了膜的结构,并测试了其吸水率、力学性能、酶降解性能。结果表明,交联作用明显提高了膜的抗张强度和抗水性,并有效地降低了溶菌酶对其降解速率。     

交联壳聚糖膜的制备及其性能的研究

用环氧氯丙烷成功地制备出交联壳聚糖膜。用FTIR,XRD和SEM方法表征其结构,并测试了其力学性能。结果表明,壳聚糖在低温下只有氨基参与交联反应,反应温度高于40℃时,羟基才发生反应;环氧氯丙烷的交联作用显着提高了壳聚糖膜的抗张强度,并有效地降低了溶菌酶对其降解速率;该交联膜有望用作可控降解的生物医用材料。     

壳聚糖/聚乙烯醇共混超细纤维的制备及紫外光交联研究

用静电纺丝法制备壳聚糖/聚乙烯醇的共混超细纤维,采用扫描电镜考察了纺丝液浓度、共混物配比、喷丝口内径对纤维形貌的影响.此外,为减少壳聚糖/聚乙烯醇纤维膜的溶胀变形,在上述体系中加入可光交联的单体二缩三乙二醇双甲基丙烯酸酯(TEGDMA)、引发剂2-羟基-2-甲基-1苯基丙酮(1173),对电纺纤维进行紫外光交联.结果表明,当壳聚糖与聚乙烯醇质量比为8:2的共混体系中加入占混合溶液质量分数4%的TEGDMA、0.12%的1173作为交联剂时,所得的无纺布纤维直径比较均一,平均约为200 nm,经光交联处理后其耐水性能得到提高.     

丙烯酸(4-N,N-二甲氨基肉桂酰氧乙基)酯及其水溶性聚合物的合成及其光化学性质研究

合成了一种新型感光性单体丙烯酸(4 N,N 二甲氨基肉桂酰氧乙基)酯(DMACEA)及其与丙烯酸的共聚物P(DMACEA co AA).用紫外吸收和荧光光谱研究了聚合物溶液的光敏感性,用傅立叶红外光谱研究了聚合物成膜后的光交联性及其过程.结果表明:DMACEA具有较好的光敏性,P(DMACEA co AA)具有较好光交联性,交联膜水溶胀和透光性也较好.     

医用壳聚糖膜的制备和性能研究

研究了壳聚糖膜的制备方法和性能。探讨了壳聚糖浓度、甘油和戊二醛用量对壳聚糖膜性能的影响,并考察了膜的体外降解过程。结果表明w=．02的壳聚糖溶液成膜效果较好;甘油和戊二醛能王著改善壳聚糖膜的力学性能和尺寸稳定性能;溶茼酶-林格氏液中浸泡40d后膜的降解率为41．98％。满足引导组织再生材料的基本要求。该膜作为一种潜在的生物医用材料,将具有较广阔的应用前景。     

原位沉析法制备壳聚糖棒材的研究

以壳聚糖凝胶膜为模板,将壳聚糖溶液与NaOH凝固液隔离,利用膜渗透原位沉析法制备了高性能的壳聚糖棒材(d=4.5mm),其弯曲强度、弯曲模量和剪切强度分别为92.4MPa,4.1GPa和36.5MPa.扫描电子显微镜(SEM)分析结果表明,原位沉析法制备的壳聚糖棒材具有同心筒状层叠结构,并对其成型机理进行了探讨.     

可降解抑菌的蓖麻油改性水性聚氨酯复合膜的制备和性能

本研究采用水性聚氨酯(WPU)为复合材料基材,通过蓖麻油(C.O)改性,加入天然高分子抗菌物质壳聚糖(CTS),以及具有较好降解性的羟乙基纤维素(HEC),制备了一种环保抑菌可降解抑菌C.O-WPU/CTS/HEC膜.研究结果表明,CTS与HEC的含量均为1.00%时,抑菌性能达到最高;且C.O含量达到8.33%时,吸水率低于10.00%,接触角达到99.47°.抑菌实验表明C.O-WPU/CTS/HEC膜具有良好抑菌性和抑菌持久性.C.OWPU/CTS/HEC膜的生物降解实验显示,降解后(CO_(2exp)/CO_(2the))_(max)=56.30%,(w_(loss))_(max)=74.40%.同时,降解前后的扫描电镜(SEM)图片显示C.O-WPU/CTS/HEC膜具有可降解性.红外光谱分析(FT-IR)显示制备了一种性质稳定的C.O-WPU/CTS/HEC复合材料.C.O-WPU/CTS/HEC膜在实际水体中的抑菌实验说明该材料有较好的应用前景.     

具生物活性的快速光交联生物可降解水凝胶的设计合成

采用开环聚合方法合成了一系列水溶性生物可降解的低聚(丙交酯-co-丙烯酸酯碳酸酯)-b-聚乙二醇-b-低聚(丙交酯-co-丙烯酸酯碳酸酯)(OLAC-PEG-OLAC)三嵌段共聚物,并通过光交联方法方便制备得到具生物活性的新型生物可降解水凝胶.流变测试表明水凝胶储存模量(170～10000 Pa)和凝胶时间(0.8～8min)均可通过调节丙烯酸酯碳酸酯(AC)单元数、聚合物浓度及光引发剂浓度等得到控制.降解实验表明水凝胶的降解速率可通过改变AC和丙交酯(LA)单元数进行调控.含巯基的生物活性分子如RGDC短肽可通过迈克尔加成反应直接链接到OLAC-PEG-OLAC上,由此可方便制备可注射性的具生物活性的生物可降解水凝胶.MG63成骨细胞实验表明RGDC短肽功能化的OLAC-PEG-OLAC水凝胶可很好地促进细胞黏附和生长.该快速光交联生物可降解水凝胶以其优异的凝胶、降解和生物功能化等性能可望为生物组织工程提供理想的三维活性多孔支架.     

Cu(Ⅱ)对壳聚糖的配位控制降解

对壳聚糖进行液态均相络合反应制得壳聚糖铜配合物,IR、UV、元素分析及热重分析等检测证实了壳聚糖铜配合物中配位键的存在,且显示壳聚糖在形成配位结构后存在有利于降解的优势构象。以H₂O₂对壳聚糖-Cu(Ⅱ)络合物及壳聚糖进行氧化降解,考察降解过程中粘度的变化及降解产物分子量分布,在相同的降解条件下,壳聚糖铜配合物的降解速度明显高于壳聚糖,降解产物分子量分布较壳聚糖直接降解窄,结果进一步证明壳聚糖铜配合物中存在有利于降解的优势结构,同时证明以金属离子Cu(Ⅱ)对壳聚     

Modification of mechanical and thermal property of chitosan–starch blend films

Chitosan–starch blend films (thickness 0.2 mm) of different composition were prepared by casting and their mechanical properties were studied. To improve the properties of chitosan–starch films, glycerol and mustard oil of different composition were used. Chitosan–starch films, incorporated with glycerol and mustard oil, were further modified with monomer 2-hydroxyethyl methacrylate (HEMA) using gamma radiation. The modified films showed improvement in both tensile strength and elongation at break than the pure chitosan–starch films. Water uptake of the films reduced significantly than the pure chitosan–starch film. Thermo gravimetric analysis (TGA) and dynamic mechanical analysis (DMA) showed that the modified films experience less thermal degradation than the pure films. Scanning electron microscopy (SEM) and FTIR were used to investigate the morphology and molecular interaction of the blend film, respectively.     

Biobased films prepared from NaOH/thiourea aqueous solution of chitosan and linter cellulose

In the present study, films based on linter cellulose and chitosan were prepared using an aqueous solution of sodium hydroxide (NaOH)/thiourea as the solvent system. The dissolution process of cellulose and chitosan in NaOH/thiourea aqueous solution was followed by the partial chain depolymerization of both biopolymers, which facilitates their solubilization. Biobased films with different chitosan/cellulose ratios were then elaborated by a casting method and subsequent solvent evaporation. They were characterized by X-ray analysis, scanning electron microscopy (SEM), atomic force microscopy (AFM), thermal analysis, and tests related to tensile strength and biodegradation properties. The SEM images of the biofilms with 50/50 and 60/40 ratio of chitosan/cellulose showed surfaces more wrinkled than the others. The AFM images indicated that higher the content of chitosan in the biobased composite film, higher is the average roughness value. It was inferred through thermal analysis that the thermal stability was affected by the presence of chitosan in the films; the initial temperature of decomposition was shifted to lower levels in the presence of chitosan. Results from the tests for tensile strength indicated that the blending of cellulose and chitosan improved the mechanical properties of the films and that an increase in chitosan content led to production of films with higher tensile strength and percentage of elongation. The degradation study in a simulated soil showed that the higher the crystallinity, the lower is the biodegradation rate.     

A photocurable hydrogel/elastomer composite scaffold with bi-continuous morphology for cell encapsulation

A photocurable two-phase scaffold with a bi-continuous morphology was designed and characterized for the repair of load bearing soft tissues. An N-methacrylate glycol chitosan (MGC) hydrogel phase was used to distribute the cells and enable cell growth once crosslinked. The second phase, an elastomerprepared from a star-poly(ε-caprolactone-co-D,L-lactide) triacrylate, was used to enhance the mechanical properties. Chondrocytes were photocrosslinked within the bi-continuous scaffolds and proliferated, increased metabolic activity and accumulated extracellular matrix over a 14 d culture period. Also during this time no significant material degradation was observed.     

壳聚糖水杨酸盐-明胶共混膜结构表征及其抗菌性

以溶液共混法成功制备出壳聚糖水杨酸盐－明胶共浊膜，用FT－IR、XRD、SEM表征了其结构，并测试了其吸水率，力学性能及抑菌性能。结果表明，壳聚糖水杨酸盐－胶胶共混膜中存在强烈的氢键相互作用及良好相容性，共混膜的力学性能随明胶含量增大而明显提高，当明胶含量为30％时，共混膜的抗张强度最大，其干、湿态抗张强度分别达99．9MPa和34．9MPa，比纯壳聚糖膜干，湿态抗张强度分别提高了99．8％有83．75，共浊膜抑菌性随明胶含量增加而下降，但其抑菌性仍明显高于壳聚糖膜。水杨酸的引入有利于改善其力学性能及抗菌性能，该共漫漫经膜作为一种潜在的伤口包扎材料，将具有广阔应用前景。     

Properties of water-soluble carboxymethyl chitosan film modified by hydrophobic poly(propylene glycol)

A series of water-soluble carboxymethyl chitosan (CMCS)/poly(propylene glycol) (PPG) blend films with various CMCS/PPG mole ratios were prepared by the solution casting method. Morphology of the CMCS/PPG blend films was investigated by scanning electron microscopy (SEM). Thermal, mechanical, and chemical properties of the CMCS/PPG blend films were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile tests, and contact angle tests. It was found that the introduction of PPG can markedly affect the morphology and the properties of CMCS films.     

EFFECTS OF BLENDING CHITOSAN WITH PEG ON SURFACE MORPHOLOGY,CRYSTALLIZATION AND THERMAL PROPERTIES

Biodegradable blend films composed of chitosan and PEG with various composition ratios were prepared.The chemical structure of the blend films was characterized with FTIR and X-ray,which showed no chemical bond formations but certain interactions probably coming from the hydrogen bonds.Morphologies of these blend films were viewed using AFM and SEM,suggesting that pure chitosan film had a smooth surface structure and the blend films surface showed a plenty of holes with varying size.Through the DMA measu...     

Effectiveness of silane monomer and gamma radiation on chitosan films and PCL-based composites

Chitosan films were prepared by casting from its 1% (w/w) solution. Tensile strength (TS) and tensile modulus (TM) of chitosan films were found to be 30 MPa and 450 MPa, respectively. Silane monomer (3-aminopropyl tri-methoxysilane) (0.25%, w/w) was added into the chitosan solution (1%, w/w) and films were casted. Then films were exposed to gamma radiation (5–25 kGy) and mechanical properties were investigated. It was found that at 10 kGy, the values of TS and TM were improved significantly. Silane grafted chitosan film reinforced poly(caprolactone) (PCL)-based tri-layer composites were prepared by compression molding. Silane improved interfacial adhesion between chitosan and PCL in composites. Surface of the films was investigated by scanning electron microscope (SEM) and found better morphology for silane grafted films.