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透明质酸及其衍生物作药物载体 总被引:6,自引:0,他引:6
透明质酸(HA)具有良好的生物相容性和生物降解性,是优良的药物载体。但其稳定性差,对强酸、强碱、热、自由基及透明质酸酶敏感,容易发生降解而限制了其应用。本文简要介绍HA的基本特性及应用,重点阐述了HA经不同的化学改性方法如酯化、交联、接枝所得衍生物作药物载体的最新研究进展。化学改性赋予了HA一系列的优良特性,如适当的机械强度、特殊的流变学特性、良好的稳定性、靶向性等,可提高、扩大HA作药物载体的性能和应用范围。最后展望了透明质酸及其衍生物作药物载体的应用前景。 相似文献
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生物塑料、生物降解塑料、生物基塑料统称为环境友好塑料,但它们三者的侧重点各有不同,既有区别,也有联系,本文对以上三个概念的意义做了详细的解释和澄清。生物塑料注重于生产原料的生物来源性和制造过程的生物技术性;生物降解塑料则注重于它是否可以被生物降解,其原料可以来自于可再生资源,也可来自于石油资源;生物基塑料则关注其生产原料是否来自于可再生资源,而对其是否可以生物降解没有特别要求。 相似文献
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脂肪族聚酯是一种可生物降解的新型高聚物,可通过化学催化、发酵和酶催化来合成.酶催化合成聚酯是一种新型的环境友好绿色化学技术,可以在温和条件下高效的合成聚酯,有着传统聚合方法难以比拟的优势.尤其是特种酶的应用,为传统方法难以合成的聚酯,开辟了一条新的合成途径.本文综述了脂肪酶催化缩聚、酯交换、内酯开环聚合等聚酯合成方法,并讨论了反应参数(如溶剂、温度、酶和单体的浓度)对反应的影响. 相似文献
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<正>Two novel biodegradable thermosensitive polyphosphazenes with lactic acid ester and methoxyethoxyethoxy side groups were synthesized via the macromolecular substitution reactions of poly(dichlorophosphazene) with the sodium salt of lactic acid ester and sodium methoxyethoxyethoxide.Their structures were confirmed by ~(31)p NMR,~1H NMR,~(13)C NMR,IR,DSC,and elemental analysis.The lower critical solution temperature(LCST) behavior in water and in vitro degradation property of the polymers was investigated.The results indicated that two polymers showed LCST phase transition over a range of concentrations from 0.13 to 15 wt%and pH-sensitive degradation properties. 相似文献
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Abstract Cellulose carbamate and ester derivatives were synthesized in homogeneous solutions of lithium chloride (LiCl)/N,N-dimemyl-acetamide (DMAc) by the reaction of cellulose with ethyl 4-isocyanatobenzoate and the activated esters of N,N-dimethyl-aminobenzoic acids. Comparative reactions were performed with phenyl isocyanate and the activated ester of benzoic acid. All reactions were followed spectroscopically by FTIR, 1H NMR, and 13C NMR. Degrees of substitution were calculated utilizing UV spectroscopy. The isocyanate reactions are facile allowing controllable degrees of substitution and high yields. By contrast, the activated ester pathway inherently results in lower degrees of substitution and lower yields due in part to undesirable side reactions. 相似文献
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合成了9-丁基咔唑基聚炔汞聚合物[—HgC≡CRC≡C—]n及其二聚体[MeHgC≡CRC≡CHgMe]和金的二聚体[(PPh3)AuC≡CRC≡CAu(PPh3)](R=9-丁基咔唑基). 用 1H NMR, 13C NMR, 31P NMR, FTIR, FAB-MS, UV-Vis, Fluorescence及Phosphorescence 光谱对其进行了表征. 结果表明, 体系中金和汞产生的重原子效应可以促进单线激发态S1与三线激发态T1的系间跃迁, 使标题化合物产生有机三线态发光. 相似文献
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光谱法分析乙丙共聚物的序列结构及链节比 总被引:3,自引:0,他引:3
用FTIR, 1 H NMR和 13 C NMR分析乙丙共聚物的序列结构与链节比. 通过对乙丙共聚物 1 H NMR, 13 C NMR和 13 C-1 H二维核磁共振谱的综合分析, 提出了与前人不同的归属, 并提出了不同位置碳原子积分面积相关性分析方法, 该方法避免了烦琐的理论计算, 可简便地得到乙丙共聚物的主要序列结构. 通过比较 1 H NMR和 13 C NMR计算乙丙共聚物中乙烯、 丙烯链节比, 表明可以用 1 H NMR代替 13 C NMR完成对乙丙共聚物中乙烯、 丙烯链节比的定量计算. 相似文献
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HUANG XiaoBin CHEN KuiYong LI Jing ZHENG YuanLi JIANG JinGui & TANG XiaoZhen College of Chemistry Chemical Engineering Shanghai Jiao Tong University Shanghai China 《中国科学B辑(英文版)》2011,(3)
Polydichlorophosphazene(PDCP)was synthesized from PCl5 and NH4Cl via a one-pot approach,and then further reacted with glycine ethyl ester and methylparaben via a two-step nucleophilic substitution approach to give poly(methylparaben/glycine ethyl ester)phosphazene(PMGP),which was a kind of mix-substituted biodegradable polymer.NMR and FT-IR were used to characterize its structure.A series of experiments were conducted to study the effects of the ratio of methylparaben to glycine ethyl ester and the experime... 相似文献
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《结构化学》2019,38(10)
In this paper, a new Pd-based complex that contains N-heterocyclic carbene(NHC) and triphenylphosphine(PPh3) ligands was synthesized. The cis-(NHC)Pd Br_2(PPh3) complex has been prepared by the substitution of 3-chloropyridine ligand in(NHC)PdBr_2(3-chloropyridine) complex with triphenylphosphine. This complex has been characterized by using ~1H NMR, 31 P {~1H} NMR, ~(13)C {~1H} NMR, FTIR, UV-Vis spectroscopy and elemental analysis techniques. The molecular and crystal structures of the cis-(NHC)PdBr_2(PPh3) complex were determined by singlecrystal X-ray diffraction method. 相似文献
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Dionisio M Schnorr JM Michaelis VK Griffin RG Swager TM Dalcanale E 《Journal of the American Chemical Society》2012,134(15):6540-6543
Single-walled carbon nanotubes (SWCNTs) have been functionalized with highly selective tetraphosphonate cavitand receptors. The binding of charged N-methylammonium species to the functionalized SWCNTs was analyzed by X-ray photoelectron spectroscopy and confirmed by (31)P MAS NMR spectroscopy. The cavitand-functionalized SWCNTs were shown to function as chemiresistive sensory materials for the detection of sarcosine and its ethyl ester hydrochloride in water with high selectivity at concentrations as low as 0.02 mM. Exposure to sarcosine and its derivative resulted in an increased conductance, in contrast to a decreased conductance response observed for potential interferents such as the structurally related glycine ethyl ester hydrochloride. 相似文献
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以PCl5和NH4Cl为原料,利用一锅法制备了聚二氯膦腈,通过两步亲核取代反应,分别以甘氨酸乙酯和对羟基苯甲酸甲酯为亲核试剂,合成了混合取代可生物降解聚[(对羟基苯甲酸甲酯/甘氨酸乙酯)膦腈].用核磁共振波谱及红外光谱等对产物结构进行了表征.研究了甘氨酸乙酯和对羟基苯甲酸甲酯的比例及外界环境对所制备的聚膦腈降解性能的影响,并进行了体外降解实验.研究结果表明,通过改变甘氨酸乙酯和对羟基苯甲酸甲酯的比例,可获得一种降解速率可调节的生物降解膦腈聚合物. 相似文献