Influence of Addition of Hyaluronic Acid (HA) on the Properties of Collagen/HA Composite Scaffolds

In order to develop a scaffolding material for tissue regeneration, porous matrices containing varying composites of collagen and hyaluronic acid (HA) (from 1:0 to 0:1) were fabricated using a freeze-drying method. The effect of the composition on the morphology, hydrophilicity, swelling behavior, mechanical properties, and in vitro cytotoxicity was investigated. The results showed that all the scaffolds had an interconnected pore structure with sufficient pore size for use as a support for the growth of fibroblasts. The addition of HA improved the swelling property, but reduced the compressive strength. The contact angle decreased with increasing HA content. In in vitro cytotoxicity tests using fibroblastic cells, the collagen/HA scaffolds showed no toxicity. All these results suggest that collagen/HA composite scaffolds are a potential candidate for tissue engineering scaffolds.     

Preparation and Characterization of Hyaluronic Acid Hydrogel Blends with Gelatin

Porous hydrogel blends composed of various weight ratios of hyaluronic acid (HA) and gelatin (Gel) were fabricated by a freeze-drying method. The 1-ethyl-3(3-dimethylaminopropyl) carbodiimide (EDC) was used as a crosslinker to improve their biostability. The effect of the component and crosslinker content on the morphology, swelling ratio (SR), and mechanical properties were investigated. The results indicated that after chemical crosslinking the hydrogel showed a smoother and denser surface with less pores and a crosssection with smaller pores than that without crosslinking. The crosssection morphologies of the HA/Gel hydrogels changed from a sheet-like appearance to a fiber-like appearance with increasing HA content. The addition of HA improved the swelling property, but reduced the compressive strength. As the crosslinker content increased, the SR decreased; however, the compressive strength of the HA/Gel hydrogels increased. All these results suggest that HA/Gel hydrogel crosslinked by EDC is a potential candidate for tissue engineering scaffolds.     

偶氮染料酸性黄的合成及光致发光性能

酸性黄是经过重氮化和偶合反应合成的一种偶氮染料,对它进行了IR、1H-NMR和元素分析的表征.进一步研究它的光致发光性质,结果表明:它的荧光发射为黄绿色光,其发射光谱有明显的溶剂效应,并且随着溶剂极性(乙酰乙酸乙酯、乙醇、吡啶和N,N-二甲基甲酰胺)的增大荧光光谱向长波方向移动(即发生红移);温度和过渡金属离子对它的荧光光谱有较大的影响.     

A Biophysical Study of Ru(II) Polypyridyl Complex,Properties and its Interaction with DNA

Mononuclear Ru(II)Polypyridyl complexes of type [Ru(A)₂BPIIP] (ClO₄)₂.2H₂O, where BPIIP?=?2-(3-(4-bromophenyl)isoxazole-5-yl)-1 H-imidazo [4,5-f] [1, 10] phenanthroline and A?=?bpy?=?bipyridyl (1), phen?=?1,10 Phenanthroline (2), dmb?=?4, 4' -dimethyl 2, 2'- bipyridine (3) & dmp?=?4,4'-dimethyl-1,10 –Ortho Phenanthroline (4), were synthesized and their antibacterial activity were examined. The synthesized complexes were characterized and their interaction with DNA was studied using Computational and Biophysical methods (Absorption, emission methods, and viscosity). Molecular modelling studies were carried out for molecular geometry and electronic properties (Frontier molecular orbital HOMO—LUMO). The electrostatic potential surface contours for the complexes were analysed to give their nucleophilic level of sensitivity. The study reveals that the Ru(II) Polypyridyl complexes bind to DNA preponderantly by intercalation. The results recommend that the phen and dmp complex have more effective binding ability than the bpy and dmb, indicating the role of the ancillary ligand in determining their specificity for DNA binding. Further molecular docking studies suggested an octahedral geometry and bind to DNA by preferential binding to Guanine. The docking study additionally sustains the binding constant data acquired with the absorption and emission techniques.The results reveal that the nature of the ancillary Ligand plays a considerable role for the intercalation of the Ru(II) polypyridyl complex to DNA, which subsequently influences the antibacterial activity. Biological studies conducted on Gram‐Negative (E.coli and K.pneumonia) and Gram-Positive (S. aureus and E. faecalis) bacteria establish that complex 1 and 2 were considerably active against S. aureus and E. coli.

     

Thermal Properties of Fe-octacarboxyl Acid Phthalocyanine/Polyurethane Blends

The thermal stability of PU has been a critical factor to influence its applications as engineering materials. In this paper, the thermal properties of Fe-octacarboxyl acid phthalocyanine (Fe-OCAP)/polyurethane (PU) blends were investigated. The glass transition temperatures (T_g) of Fe-OCAP/PU blends were analyzed by differential scanning calorimetry (DSC). The results showed that with increasing Fe-OCAP content up to 10% T_g of the samples decreased. Thermal stability of the samples was studied by thermogravimetric analysis (TGA). The decrease of the degradation rate of the samples with increasing Fe-OCAP content indicated an improvement of thermal stability for the modified samples. The activation energy of thermal degradation was calculated by the Freeman and Carroll method. The results showed that the activation energy increased with increasing Fe-OCAP content, which also indicated the improved thermal stability obtained in the modified samples. The thermal properties of the samples were influenced by the incorporation of Fe-OCAP.     

铽-丙烯酸聚合物薄膜的制备和谱学性质

以键合方式制备了键合型稀土聚合物－铽－丙烯酸聚合物,通过三维荧光光谱确定了铽在丙烯酸聚合物中的最佳激发波长为306nm,最强发射波长为544nm,Tb-丙烯酸聚合物薄膜在306nm光激发下,产生Tb^3 的特征发射,归属于^5D4-^7FJ跃迁（J＝6,5,4,3）,其最大发射位于544nm,归属于Tb^3 的^5D4-^7F5跃迁,呈现强的绿色发射,说明丙烯酸的聚合没有影响Tb^3 的发光性质,而Tb^3 的参入也没有影响丙烯酸的透明性。通过发射光谱、激发光谱、中红外光谱、远红外光谱和拉曼光谱,研究了铽－丙烯酸聚合物薄膜的荧光性质和谱学性质。     

枞酸十二醇酯琥珀酸酐的合成与表征

以枞酸为起点 ,合成了十二醇酯琥珀酸酐 ,采用红外光谱、核磁共振波谱及质谱对中间产物及终产物进行了结构表证。     

Properties of Ferrofluid Nanoparticles Prepared by Coprecipitation and Acid Treatment

A new stable acid water-based CoFe₂O₄ ferrofluid is prepared by coprecipitation and acid treatment. The properties of the nanoparticles forming the ferrofluid are examined by means of X-ray diffraction, vibrating sample magnetometer, scanning tunneling microscopy, transmission electron microscopy and annihilation technique. The results show that the particles are cubic CoFe₂O₄ nanoparticles, which have an average diameter of 12.2nm and are coated with a low density porous amorphous layer. The CoFe₂O₄ particles in an acid aqueous medium exist in two kinds of forms, one is a single spherical particle and another is an aggregation of several spherical particles.     

咖啡酸及其衍生物光谱特性研究

研究了不同pH值条件下 ,咖啡酸类化合物溶液的荧光及紫外光谱特性。实验结果表明 :咖啡酸类化合物有很宽的pH发光范围 (2～ 1 2 ) ,发光强度、光谱形状及峰位随pH值不同而异 ,且在pH =9～ 1 0时 ,咖啡酸类化合物荧光强度最强。研究还发现 :咖啡酸类化合物 4 位酚羟基的解离可导致荧光强度显著增强 ,而 3 位酚羟基的解离可能会导致荧光猝灭 ,并且在强酸和强碱介质中发射荧光均被显著猝灭 ;此外 ,在强碱性介质中紫外光谱形状有很大变化 ,表明咖啡酸类化合物在强碱性下分子结构发生了明显改变。     

稀土与对茴香酸配合物的合成和性质

本文以茴香酸为栩体，合成了与稀土离子的二元配合物ＲＥＬ３．对所合成的配合物进行了元素分析，红外光谱分析，紫外光谱分析和核磁共振分子等分析测试，初步研究了该类配合物的结构和性质。     

2-芳基苯丙酸类药物在混合溶剂中的荧光光谱

测定了298K时2-芳基丙酸类药物普拉洛芬、酮洛芬、卡洛芬、萘普生在二元混合溶剂中的荧光光谱,采用Jouyban-Acree模型拟合了荧光强度（FI）数据,平均偏差为1.9％,当采用Yalkowsky方程拟合时,平均偏差达到13.5％.首次采用Jouyban-Acree模型拟合最大荧光发射波长,平均误差为0.3nm,而采用Yalkowsky方程时,误差为0.9nm.结果表明Jouyban-Acree模型能够很好预测混合水溶液中药物的荧光强度及荧光最大发射波长,当数据较少时,Yalkowsky方程也能预测混合溶剂中的最大发射波长.     

Foaming and Damping Properties of Ethylene Vinyl-Acetate Copolymer/Polylactic Acid Blends

With ethylene vinyl-acetate copolymer (EVM) and polylactic acid (PLA) blends as the matrix, dicumyl peroxide (DCP) as the curing agent and azodicarbonamide (AC) as the foaming agent, EVM/PLA foamed blends were prepared by compression molding. The effects of different amounts of AC, DCP, and silica, as well as varying foaming time, on the cell structure and damping properties of the EVM/PLA-foamed blends were examined by scanning election microscopy (SEM) and dynamic mechanical analysis (DMA). The results showed that the cell size and damping properties varied little with increasing AC content in the compounds; however, the cell size declined slightly as DCP increased and the damping properties rose slightly, exhibiting an optimum set of properties at 5 phr of DCP. The cell size declined dramatically and damping increased significantly as the foaming time was increased. Moreover, both suddenly increased after 5 min foaming. It was found that the damping properties of the foamed materials increased with decreasing cell size and increasing number of cells. The cell size also decreased and damping properties increased as the silica content was increased. The silica interacted more strongly with EVM than with PLA.     

含磺酸基的聚硅氧烷类光致变色液晶的合成及性能

通过重氮化反应合成了末端为磺酸基的刚性基元,再经过取代、加成、酯化反应最终合成了偶氮苯类聚硅氧烷液晶。通过UV表明其具有类似小分子的光致变性。并用POM、DSC对其液晶行为进行了表征,结果表明该化合物属于近晶A型液晶,相变区间为191.04—274.95℃,液晶范围较宽,有望作为光控开关和新型信息存储材料。