新型HPWs@MIL-101催化剂的制备、表征及其催化性能

采用直接合成法将磷钨杂多酸(HPWs)固载到金属-有机骨架材料MIL-101的介孔笼中,制得新型HPWs@MIL-101多相催化剂。利用XRD、N2吸附、扫描电镜(SEM)、XPS、UV-Vis DRS、Raman和FT-IR等手段对该催化剂进行了表征,并研究了其在环戊烯选择氧化制备戊二醛反应中的催化性能。结果表明,磷钨杂多酸高度分散在金属-有机骨架MIL-101的介孔笼中,将磷钨杂多酸固载到MIL-101上后,能够很好地保持磷钨杂多酸的Keggin结构和载体MIL-101的晶体骨架结构。HPWs@MIL-101催化剂的催化性能远高于传统浸渍法制备的催化剂的催化性能,当磷钨杂多酸的负载量为12.5%(w)时,HPWs@MIL-101表现出最优的催化性能,环戊烯转化率高达100%,戊二醛的得率达到78.7%。重复实验表明该催化剂具有较高的稳定性,使用三次后,GA的得率仍然达到74.1%。     

Preparation and Characterization of Chitosan-Gelatin/Glutaraldehyde Scaffolds

Chitosan-gelatin (CG) scaffolds were fabricated with glutaraldehyde as a cross-linker by vacuum freeze-drying. Mixtures of different volumes of chitosan and glutaraldehyde were considered. Morphology, porosity, density, and water absorbency of the scaffolds were studied. Both tensile and compressive properties of the scaffolds were tested. In addition, cellular adherence, proliferation, and morphology on the scaffolds were tested to evaluate the compatibility. It was found that porosity, density, water absorbency, and mechanical properties of CG scaffolds changed with the variation of chitosan or GA content. The adequate adherence, proliferation, and morphology of HaCaT type cells on the scaffolds showed that these scaffolds can be used as carriers for culturing HaCaT. The CG scaffolds, particularly those with chitosan-gelatin volume ratios of 1:1 and adding 6% or 8% volume of 0.25 wt% GA solution, were more suitable than the others through comparing the above properties and could be promising candidates for engineering skin tissue.     

Development of Lactose Biosensor Based on β‐Galactosidase and Glucose Oxidase Immobilized into Gelatin

In this article, we describe the preparation of a new lactose biosensor based on electrode coating with β‐galactosidase and glucose oxidase immobilized gelatin. For this purpose, β‐galactosidase and glucose oxidase enzymes were immobilized onto gelatin by crosslinking with glutaraldehyde. Properties of the immobilized β‐galactosidase and glucose oxidase enzymes electrode have been studied. The effects of glutaraldehyde concentration, temperature and pH variations and reusability were among the subjects analyzed. Lactose biosensors were subjected to continuous repeated use in order to observe reusability and shelf life; where standard lactose and milk samples were used as substrate solutions. Continuous reuse experiments showed that most of the lactose biosensors activities were retained even after the 10th use in a period of 30 days.     

Carboxymethyl chitosan‐montmorillonite nanoparticles for controlled delivery of isoniazid: evaluation of the effect of the glutaraldehyde and montmorillonite

Chitosan, a natural biopolymer, is used for drug delivery application. But its potential application is limited by its low solubility in aqueous media. The present study was designed to prepare carboxymethyl chitosan (CMC), a water soluble derivative of chitosan, and evaluate the prospective of crosslinked CMC‐Montmorillonite (MMT) nanoparticles for controlled delivery of isoniazid. The nanoparticles were characterized by Fourier Transmission Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), and Transmission emission microscopy (TEM). The effects of MMT and glutaraldehyde on nanoparticles were assessed with regard to encapsulation efficiency, percentage swelling degree, and cumulative release. Percentage swelling degree and cumulative release were studied in pH medium 1.2 and 7.4 for 6 h. The cumulative release was studied by UV‐visible spectrophotometer. Cell viability study was performed by MTT assay analysis. FTIR and NMR study indicated the successful preparation of CMC. FTIR study confirmed the interaction of MMT with CMC. The exfoliation of MMT layers and molecular level dispersion of isoniazid in CMC was examined by XRD and TEM. SEM study showed that the surface of the CMC‐MMT nanoparticles was smooth compared with those of CMC nanoparticles. Swelling and release of isoniazid from the nanoparticles increased with the decrease in the MMT and glutaraldehyde content. The percentage swelling degree and cumulative release was more in pH 1.2. Cell viability study revealed that CMC was not cytotoxic, and the nanoparticles containing MMT was less cytotoxic than those of MMT free nanoparticles. CMC‐MMT nanoparticles can be exploited as potential drug carrier for controlled release applications. Copyright © 2014 John Wiley & Sons, Ltd.     

NMR structural study of hydrogels based on partially deacetylated hyaluronan

Hydrogels have been prepared using two partially deacetylated hyaluronan (deHA) samples having a molar ratio of free amino groups to total initial N-acetamido groups equal to 23 and 33%, respectively. Taking advantage of such primary amino functionalities, polymeric networks could be easily obtained in aqueous media by means of two different crosslinking procedures, namely: a) Ugi multicomponent reactions and, more simply, b) glutaraldehyde reticulation. In this paper, we wish to report on the synthesis of deHA based hydrogels and, in particular, on their structural elucidation as obtained by NMR studies.

Structure of HA (R = COCH₃) and de-HA (R = H) repeat units.     

丙烯醛－乙烯基乙醚法合成戊二醛工艺中的气相色谱分析

丙烯醛－乙烯基乙醚法合成戊二醛工艺中的气相色谱分析崔庆新，尹宝霖，张立云（聊城师范学院化学系山东聊城２５２０５９）１前言由于戊二醛（ｇｌｕｔａｒａｌｄｅｈｙｄｅ）具有提高生物高分子材料的寿命和强度以及消毒、灭菌、防腐、消除抗原的特性，因此在生物医学工...     

Characterization of Chitosan-Gelatin Blend Scaffolds

Vacuum freeze-drying was used to prepare chitosan-gelatin (CG) scaffolds from hydrogels, with glutaraldehyde (GA) used as a crosslinker. The effects of the changes in volume ratios of the 2?wt% CG and GA solutions on scaffold performance were studied. The ratio of chitosan to gelatin solution volumes, vr(C/G), was adjusted to 1/2 or 1/1, with the 0.25?wt% GA volume at 3, 6, or 8% of the CG/GA volume. Six groups of CG scaffolds were fabricated and the scaffolds performance compared. After the cells were incubated for 4?days, hematoxylin eosin (HE) staining was used to observe the spreading of human skin keratinocyte (HaCaT) cells on these scaffolds, with the MTT method also used to detect the cells proliferation. The inhibition zone method was used on cells cultures to determine the antibacterial properties of the scaffolds against S. aureus and E. coli. Scaffolds were also examined for degradation in lysozyme and their compression properties were tested after degradation. The results showed that the HaCaT cells grew well on these scaffolds and proliferated significantly, indicating that these scaffolds possessed good cytocompatibility. With increased chitosan volume, the antibacterial properties of the scaffolds against S. aureus increased, however, there was no significant change in the antibacterial properties toward E. coli. Increased volumes of chitosan and GA decreased the scaffolds degradation rates and improved the elastic compressive moduli of the scaffolds after degradation. The scaffolds in the vr(C/G) = 1/1, 8% GA group have potential application prospects in the field of skin regeneration.     

新型WO3/HMS催化剂的制备及其对环戊烯选择氧化反应的催化性能

 采用草酸络合方法将WO3固载到六方介孔全硅分子筛HMS上,制得新型WO3/HMS非均相催化剂. 利用SEM,TEM,N2吸附,XRD及激光拉曼光谱等手段对催化剂进行了表征,研究了催化剂在环戊烯选择性氧化合成戊二醛反应中的催化性能. 结果表明,在WO3/HMS催化下环戊烯和H2O2的转化率均可达100%,戊二醛的选择性可达72%. WO3以高分散状态存在于催化剂表面. 单次反应后钨的溶脱量(5.5 μg/ml)很小,对反应几乎没有影响. 催化剂具有较高的稳定性,可以重复套用6次. 失活后的催化剂可通过简单焙烧的方式再生.     

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。     

聚中性红修饰玻碳电极葡萄糖生物传感器

以中性红为电子媒介体,电聚合于Nafion修饰的玻碳电极表面,以戊二醛作交联剂固定葡萄糖氧化酶,最后覆盖一层Nafion膜防止酶流失,构建一种新型葡萄糖生物传感器.详细探讨了传感器的电化学性能及对葡萄糖的最佳响应条件.结果表明,30℃时,传感器在pH 7.0的PBS中对葡萄糖的线性响应范围为1.0×10-5~5.0×10-3mol.L-1.该传感器制作简单、性能优良,有潜在应用前景.