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合成了侧基含环糊精的聚异丙基丙烯酰胺(PnipamCD), 该聚合物在水溶液中具有较高的最低临界溶解温度(LCST). 快速升温到溶液的LCST以上可形成球形胶束, 慢速升温到LCST以上可形成空心囊泡. 在PNIPAM的选择性溶剂中, PnipamCD形成棒状组装体. 相似文献
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利用X射线衍射分析和核磁方法研究了单(6-氧-6-苯基)-β-环糊精(1)在固态和液态中的分子自组装行为. 结果表明, 在固态中连接于环糊精主面的芳香基团从次面插入到另一个环糊精的空腔形成了二重对称轴的螺旋结构; 在溶液中该修饰环糊精自组装形成聚集体的键合常数为240 mol-1·L. 这些研究结果与报道的单(6-脱氧-6-苯胺基)-β-环糊精(2)、单(6-脱氧-6-苯硒基)-β-环糊精(3)和单(6-脱氧-6-苯巯基)-β-环糊精(4)一起, 进一步揭示了分子自组装形成超分子的一些控制因素. 相似文献
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胶原是人类最主要的结构蛋白,在体内通过自组装形成具有D带的纤维结构,构成人体的各种组织。胶原蛋白具有优异的生物相容性、生物可降解性、无毒性、低免疫性等特点,在材料科学、生物医学、组织工程、生物传感器等领域得到了越来越多的研究和应用。近年来,人们发现,通过合理调控外界环境,胶原蛋白在体外能自组装形成有序的超分子聚集结构,胶原蛋白在体外的自组装行为引起了研究者的广泛关注,逐渐成为研究的热点。本文概括了胶原的自组装机理、外界环境条件对胶原自组装的影响以及胶原自组装基复合材料等方面的工作。 相似文献
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环糊精包合作用诱导聚合物自组装的研究进展 总被引:2,自引:0,他引:2
将主客体识别与聚合物自组装相结合,利用环糊精对聚合物的包合作用在溶液中诱导聚合物组装形成结构可控的纳米粒子,形成有别于基于环糊精/聚合物包合作用形成的结晶粉末和超分子水凝胶的新型材料.本文介绍了这种诱导组装方案的研究背景及最新的研究成果,综述了诱导组装的原理、特点及影响因素.研究表明,由这种方案制备的聚合物纳米粒子具有超分子动态可逆的特征,进而显示出对温度和pH等敏感的性质.该类环糊精包合作用诱导组装的聚合物超分子聚集体在生物医学材料方面具有潜在的应用价值,如用作药物和基因的可控传递释放载体. 相似文献
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直链淀粉在溶液中可形成单螺旋链,并作为一种主体分子通过疏水相互作用与各种疏水性客体分子发生包结络合作用。本文对直链淀粉包结络合作用的研究进展进行了综述,详细介绍了直链淀粉包结络合物的种类及制备方法,还介绍了直链淀粉包结络合作用在面粉食品和新材料制备中的应用。 相似文献
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环糊精包合作用对疏水缔合聚合物流变调节与应用 总被引:1,自引:0,他引:1
近年来,利用超分子作用力调节体系流变行为备受人们关注,已在多领域中展现出广泛的应用前景。而环糊精包合作用是一类重要的超分子作用力,向缔合聚合物水溶液中加入环糊精,将拆散缔合结构,引起粘度和粘弹性急剧下降;竞争客体或酶的加入又会诱导分子间发生新的组装行为,使体系流变性得到恢复。本文综述了基于环糊精包合作用的分子组装与流变调节在理论及应用方面的研究现状,重点介绍了环糊精对不同缔合聚合物溶液的流变影响规律和外加物质对体系流变恢复的调节。 相似文献
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The driving forces leading to the inclusion complexation of cyclodextrins were reviewed, which included the electrostatic interaction, van der Waalsinteraction, hydrophobic interaction, hydrogen bonding, release of conformational strain,exclusion of cavity-bound high-energy water, and charge–transferinteraction. It was shown that except for the release of conformation strain and exclusion of cavity-bound water, the otherinteractions were indeed contributive to the complex formation. However, it was concludedthat the enthalpy and entropy changes of the complexation were not good criteria to be used injudging whether a particular driving force was present or important, mainly because of theoccurrence of enthalpy-entropy compensation. On the other hand, the multivariate quantitativestructure-activity relationship analyses usually could illustrate which driving forces wereimportant in certain inclusion complexation systems. 相似文献
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水溶液中环糊精包结物的包结常数的测定方法 总被引:21,自引:0,他引:21
环糊精(CD)是由6,7,8个葡萄糖基构成的环状化合物,分别叫做α、β、γ-CD,它们具有“外亲水,内疏水”的独特性质,可以与多种物质形成包结物,而改变物质的特性,因而被广泛应用于各行各业中,在以往研究的基础上,总结了多种测定环糊精包结常数的方法,以便能更好地研究并开发利用具有极大潜力的环糊精。 相似文献
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A Theoretical Study on the Inclusion Complexation of Cyclodextrins with Inorganic Cations and Anions
Yao Fu Lei Liu Qing-Xiang Guo 《Journal of inclusion phenomena and macrocyclic chemistry》2002,43(3-4):223-229
PM3 and B3LYP/3-21+g(d) calculations were performed on theinclusion complexation of- and -cyclodextrin with inorganic cationsand anions includingLi+, Na+, F-, and Cl-. Both the gas-phase interaction and solvent effect weretaken into consideration. The CD complex with an anionwas more stable than that with acation, which was in agreement with the experimentalfindings. It was proposed thathydrogen bonding between the anion and the cyclodextrincavity was the physical origin ofsuch behavior. 相似文献
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Joanna Taraszewska Magorzata Ko
bia 《Journal of inclusion phenomena and macrocyclic chemistry》2005,53(3):155-161
Complexation of ketoconazole (KET), a broad-spectrum antifungal drug, with β- and γ-cyclodextrins (CDs), heptakis (2,6-di-O-methyl)-β-CD (2,6-DM-β-CD), heptakis (2,3,6-tri-O-methyl)-β-CD (TM-β-CD), 2-hydroxypropyl-β-CD (2HP-β-CD) and carboxymethyl-β-CD (CM-β-CD) was studied. The stability constants were determined by the solubility method at pH = 6 and for 2,6-DM-β-CD and CM-β-CD at pH = 5. At pH = 6, the stability constants increased in the order: TM-β-D < γ-CD < 2HP-β-CD < β-CD < CM-β-CD < 2,6-DM-β-CD. At pH = 5, due to the increased ionization of KET, the stability constant with CM-β-CD increased and with 2,6-DM-β-CD decreased. For complexes of KET with 2HP-β-CD and 2,6-DM-β-CD, the thermodynamic parameters of complexation were determined from the temperature dependence of the corresponding stability constants. For β–γ and TM-β-CD complexes, calculations using HyperChem 6 software by the Amber force field were carried out to gain some insight into the host–guest geometry. 相似文献
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Buchi N. Nalluri K.P.R. Chowdary K.V.R. Murthy V. Satyanarayana A.R. Hayman G. Becket 《Journal of inclusion phenomena and macrocyclic chemistry》2005,53(1-2):103-110
The purpose of the work is physicochemical characterization of nimesulide (NI) and meloxicam (ME)–hydroxypropyl-β-cyclodextrin
(HP-β-CD) binary systems both in solution and solid states and to improve the pharmaceutical properties of NI and ME via inclusion
complexation with HP-β-CD. Binary systems of NI and ME with HP-β-CD have been characterized both in solution and solid state
by different physicochemical methods. Three types of drug–HP-β-CD binary systems, namely physical mixtures (PM), kneaded systems
(KS) and co evaporated systems (CS) in 1:1 and 1:2 molar ratios (1:1 and 1:2 M) were prepared. Phase solubility and 1H-NMR spectroscopic studies in solution state revealed 1:1 M complexation of NI and ME with HP-β-CD. A partial inclusion of
NI with HP-β-CD at both molar ratios of kneaded and co evaporated systems and a true inclusion of ME with HP-β-CD at both
molar ratios of co evaporated systems in solid state was confirmed by differential scanning calorimetry (DSC), powder X-ray
diffractometry (powder X-RD) and scanning electron microscopy (SEM) studies. Dissolution properties of NI and ME–HP-β-CD binary
systems were superior when compared to corresponding pure drugs. The aqueous solubility and dissolution properties of NI and
ME can be improved by inclusion complexation with HP-β-CD.
Author for correspondence: E-mail: nbnaid2@E-mail.uky.edu 相似文献
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Laura Ribeiro Francisco Veiga 《Journal of inclusion phenomena and macrocyclic chemistry》2002,44(1-4):251-256
Inclusion complexation between -cyclodextrin (-CD),hydroxypropyl--cyclodextrin (HP--CD), water-solublepolymers (PVP and HPMC) and vinpocetine was studied in aqueous solution and in the solid state.Phase solubility studies were used to evaluate the complexation in aqueous solution at roomtemperature. Stability constants (Kc) of binary and ternary complexes were determined spectrophotometrically. Differential scanning calorimetry (DSC)was used to characterize kneaded, co-evaporated and lyophilised binary and ternary systems.The Kc values obtained were 70.14 M-1 and 35.01 M-1 for vinpocetine--CD and vinpocetine-HP--CD and increased in a range of 17% to 94%by addition of water-soluble polymers. Some preliminary evidences ofinclusion complexation were obtained from DSC suggesting that co-evaporated and lyophilised binary andternary systems were truly inclusion complexes. 相似文献
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Jyotsna S. Torne Pradeep R. Vavia 《Journal of inclusion phenomena and macrocyclic chemistry》2006,56(1-2):253-259
The purpose of present investigation was to investigate the effect of complexation of Nelfinavir Mesylate (NM) – an Anti-HIV drug with Beta-cyclodextrin (β-CD) on its dissolution characteristics and subsequent effect on its absorption properties and bioavailability. Phase solubility studies were conducted to find the interaction of NM with β-CD. Physical mixing and milling method were used for complexation. The inclusion complexes were characterized by X-ray diffractometry, FT-IR and NMR studies and further studied by in-vitro dissolution testing. The plain NM and complex was subjected to intestinal absorption studies by using Everted intestinal sac model. Data was treated statistically by Mann–Whitney U test. Pharmacokinetic studies were carried out in rabbits using cross over design and data was treated by Student’s t test. Phase solubility studies confirmed 1:1 complex formation of NM with β-CD with stability constant of 204.84 M−1. In-vitro dissolution studies of inclusion complexes of NM with β-CD prepared by milling method (T
90=60.89 min) showed better dissolution rate kinetics in distilled water in comparison with plain NM (T
90=374.31). The increased solubility with decreased crystallinity is attributed by inclusion of NM in the cavity of β-CD, which was further confirmed by instrumental studies. Intestinal absorption studies further supports these findings by showing 2.13 times enhancement in the absorption rate of complex as compared to plain NM. The percent relative bioavailability of complex in rabbits was 185.37 as compared to the plain NM. 相似文献
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Mahmoud M. Al Omari Musa I. El-Barghouthi Mohammad B. Zughul J. Eric D. Davies Adnan A. Badwan 《Journal of solution chemistry》2008,37(2):249-264
The interaction of two benzocycloheptanes namely, pizotifen (Pizo) and ketotifen (Keto), with cyclodextrins (CDs: α-, β-, γ-, and HP-β-CDs) has been investigated by several techniques including phase solubility, X-ray powder diffractometry, 1H-nuclear magnetic resonance and molecular mechanical modeling. The effects of CD type, pH, ionic strength and temperature
on complex stability were also explored. The complex formation constant (K
11) values for the Pizo/CD system follows the decreasing order β-CD > γ-CD > HP-β-CD > α-CD. However, for the Keto/CD system it follows the decreasing order γ-CD > β-CD > HP-β-CD > α-CD. The tendency of Pizo and Keto to complex with β-CD is driven to the extent of 70% by the hydrophobic effect. Complex formation of Keto and Pizo was substantially driven
by entropy (>100 J⋅mol−1⋅K−1) but slightly retarded by enthalpy (3–8 kJ⋅mol−1). 1H-NMR and MM+ studies indicate multimodal inclusion of the methylpiperadine, thiophene and phenyl moieties into the β-CD cavity. 相似文献
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Isamu Uemasu Satoshi Kushiyama 《Journal of inclusion phenomena and macrocyclic chemistry》1994,17(2):177-185
The inclusion complexation of five volatile chlorinated hydrocarbons, i.e., chloroform, carbon tetrachloride, trichloroethylene, tetrachloroethylene, and monochlorobenzene, with branched cyclodextrins (CDs) such as monoglucosyl--CD and monomaltosyl--CD in aqueous solutions was examined. Their inclusion complexes were found to be very water soluble and the solubilities of the chlorinated hydrocarbons in aqueous solutions increased almost linearly or gradually with increasing concentration of the branched CDs. The amounts of the chlorinated hydrocarbons included in the branched CDs were well related to their molecular size and shape. In addition, the viability of application to pollution prevention is discussed. 相似文献
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Carolina M Escobar-Llanos David Díaz Guillermo Mendoza-Díaz 《Journal of inclusion phenomena and macrocyclic chemistry》1998,31(4):333-349
The formation of inclusion complexes of -, -, hydroxypropyl-- (HP--) and -cyclodextrins with phenylbutazone and oxyphenbutazone has been studied in aqueous buffer solution (pH 7.5 and 0.1 mol dm-3 NaCl), dimethylsulfoxide, and 25, 50 and 75% dimethylsulfoxide/water mixtures. These complexation reactions have been followed by UV electronic absorption spectroscopy. In addition, 1D and 2D 1H NMR spectra were recorded to obtain structural information about the inclusion complexes formed in solution; 136 binding constant values were determined at five different temperatures (288, 293, 298, 303 and 310 K) from the electronic absorption data and, from these Hbinding and Sbinding values were obtained. At the studied cyclodextrin and guest concentration ranges, 1 : 1 inclusion complexes were detected. Only in three cases were 1 : 2 complexes detected, those of phenylbutazone and oxyphenbutazone with -cyclodextrin in aqueous, and oxyphenbutazone with hydroxypropyl--cyclodextrin in 75% dimethylsulfoxide/water solutions. 相似文献