树枝状大分子用于药物载体的研究进展

树枝状大分子是近年来出现的一类新型合成纳米高分子,具有可控的三维高度支化结构、表面分布着大量的功能基团和单分散等特点,使其在生物医学等领域中日益受到广泛关注。作为一种新型非生物载体,树枝状大分子内部空腔和表面功能基团均可与药物复合,在药物输送和基因转运等方面具有广阔的应用前景。     

树枝状大分子的研究进展与应用前景

本文介绍了树枝状大分子的历史发展及其结构、性能方面的特点,并对这类大分子在各个领域可能的应用前景进行了展望。     

树枝状大分子的研究进展与应用前景

本文介绍了树枝状大分子的历史发展及其结构、性能方面的特点 ,并对这类大分子在各个领域可能的应用前景进行了展望。     

树枝状大分子的合成与应用

本文介绍了树枝状大分子的结构特点、合成方法,并阐述了树枝状大分子在众多领域中的应用价值及今后研究方向的展望。     

树枝状大分子催化剂的合成与应用研究进展

介绍了一类新型催化剂－树枝状大分子的合成方法。包括发散法，收敛法，高度核心和支化单体法及双倍指数混合生长法，同时介绍了新型催化剂的结构特点，重点论述了催化活性中心在核心和外围端基两类催化剂在加氢，Diels-Alder反应，Fischer-Tropsch反应，Heck反应，Kharasch加成反应等中的应用，展望了这类新型催化剂的发展前景。     

基于开环聚合的两亲性树枝状共聚物在化疗方面的研究

基于开环聚合构建了一种新型树枝状共聚物(PEG-G3-PCL)作为药物载体,而该药物载体是由三代树枝状聚酯(PEG-G3-OH)引发己内酯(CL)开环聚合而成的。两亲性的PEG-G3-PCL能自组装成胶束,并且对化疗药物阿霉素(DOX)拥有较高的药物装载能力和包封率。体外药物释放的研究结果表明:该胶束能快速释放DOX,装载DOX的PEG-G3-PCL胶束具有良好的化疗效果,并且PEG-G3-PCL胶束几乎无毒。     

功能树枝状大分子的研究进展

树枝状分子是一类有较大潜力的新型高分子纳米材料。目前为止,树枝状大分子的研究已经涉及生物、化学、物理学、机械学、纳米学等领域。综述了最新报道的几类功能树枝状分子在非线性光学材料、光电材料、药物化学和自组装化学方面的最新应用进展。     

异氰酸酯型树枝状大分子的合成及应用

树枝状大分子在化学、生物医学、环境保护等领域应用广泛,是近年来发展迅速的一类新型材料。介绍了树枝状大分子的研究进展、结构性能、合成方法及其应用,论述了以异氰酸酯化合物为新型单体的树枝状大分子的合成。     

聚酰胺-胺类树枝状大分子的合成与应用研究进展

聚酰胺-胺(PAMAM)类树状分子是一类高度支化、具有特定三维结构、分子尺寸和构型高度可控的树枝状大分子,其独特的分子结构与物理化学性质使之在众多领域有着广泛的应用前景,并迅速发展为研究热点之一。将PAMAM类化合物在生物医学与自组装模板两大重要领域的研究进展及成果进行了归纳与总结,同时对此类大分子未来的研究方向作以展望。     

TRIS封端树枝状大分子PAMAM的合成

采用发散法合成了以乙二胺为核的树枝状大分子聚酰胺-胺(PAMAM),以端基为酯基的半代PAMAM和三羟甲基氨基甲烷(TRIS)为原料,无水碳酸钾为催化剂,分别以二甲基亚砜和甲醇为溶剂,合成了端基被修饰的水溶性大分子PAMAM-OH和PAMAM-K,产率分别为80.3%和74.1%.采用红外光谱对产品结构进行了表征,同时对其水溶性和表面活性进行了初步的研究,结果表明:PAMAM被水溶性基团修饰后,失去了表面活性,却增强了水溶性.     

Dendrimers: synthesis,applications, and properties

Dendrimers are nano-sized, radially symmetric molecules with well-defined, homogeneous, and monodisperse structure that has a typically symmetric core, an inner shell, and an outer shell. Their three traditional macromolecular architectural classes are broadly recognized to generate rather polydisperse products of different molecular weights. A variety of dendrimers exist, and each has biological properties such as polyvalency, self-assembling, electrostatic interactions, chemical stability, low cytotoxicity, and solubility. These varied characteristics make dendrimers a good choice in the medical field, and this review covers their diverse applications.     

聚天冬氨酸衍生物的研究进展及其在药物控释和组织工程领域中的应用

聚天冬氨酸衍生物是一种具有良好生物相容性、生物降解性的新材料.作者综述了聚天冬氨酸衍生物的研究进展,介绍了共聚法、一般开环法、开环交联法制备聚天冬氨酸衍生物,以及近几年聚天冬氨酸衍生物作为共价大分子复合体、胶束药物载体、水凝胶药物载体在药物控释方面的研究进展,及其在组织工程支架上的应用.     

Dual-sensitive and folate-conjugated mixed polymeric micelles for controlled and targeted drug delivery

For this study, we prepared a new type of drug carrier with the characteristics of stimuli-responsive transition and tumor-specific recognition through the co-assembly of two series of amphiphilic block copolymers, poly(ε-caprolactone)-b-poly[triethylene glycol methacrylate-co-N-methacryloyl caproic acid] and poly(ε-caprolactone)-b-poly[triethylene glycol methacrylate-co-N-(2-(methacrylamido)ethyl) folatic amide]. The pH-dependent thermal transition and the content of the targeting ligands of the mixed polymeric micelles are well correlated with the chemical structures and compositions of these two copolymers. Doxorubicin-loaded mixed polymeric micelles are stable at body temperature in the neutral condition for prolonged circulation in blood vessels, and demonstrated rapid drug release at acidic pH levels. The cumulative drug release profiles showed a relatively slow release at pH 7.4, and a quick release of 85% in 3 h at pH 5.3. The cytotoxicity tests against FA-positive (HeLa) and FA-negative (HT-29) tumor cell lines suggest that this mixed polymeric micelle system has potential merits as a controlled and targeted drug delivery system.     

Synthesis of biocompatible dendrimers with a peripheral network formed by linking of polymerizable groups

Toward the production of unimolecular nanocapsules with biocompatible surface, we prepared a fourth generation polyamidoamine dendrimer having both a poly(ethylene glycol) (PEG) with the number average molecular weight of 2000 and a methacryloyl group at every chain end of the dendrimer through an l-lysine residue. The introduced methacryloyl groups of the dendrimer were successfully polymerized by using free radical initiators, such as azobisisobutyronitrile and dibenzoyl peroxide, as judged by ¹H NMR. GPC revealed that the molecular weight of the dendrimers having the polymerizable groups did not change after their polymerization, indicating that the polymerization of the methacryloyl groups took place within the single dendrimer. Polymerization of the methacryloyl groups resulted in a significant reduction of the affinity of the dendrimer to a guest molecule, rose bengal, suggesting that the peripheral network formed by the linking of methacryloyl groups hides the dendrimer interior. In addition, when the methacryloyl groups of the dendrimer were polymerized in the presence of rose bengal, the guest molecule was found to be tightly associated with the dendrimer.     

Preparation of poly(ethylene glycol)-modified poly(amidoamine) dendrimers with a shell of hydrophobic amino acid residues and their function as a nanocontainer

We studied the use of poly(ethylene glycol) (PEG)-modified dendrimers as a nanocapsule with a biocompatible surface. We designed PEG-modified dendrimers having a shell of hydrophobic amino acid residues in the peripheral moiety of the dendrimer to increase their encapsulation ability. Subsequently, l-phenylalanine or γ-benzyl-l-glutamate residues were introduced to all chain ends of the poly(amidoamine) G4 dendrimers. Furthermore, PEG (MW 2000) chains were attached to the amino acid residues. These hydrophobic amino acid residues rendered the PEG-modified dendrimers as more compact. After binding of Rose Bengal (RB) guest molecules to dendrimers, an assay using the Klotz plot showed that the hydrophobic amino acid layer slightly affected the guest site number, but significantly increased intrinsic binding of the dendrimers to guest molecules. The PEG-modified dendrimers with the hydrophobic amino acid layer were better able to retain guest molecules than the dendrimer without the layer: they are therefore useful for drug delivery.     

Ferrocenyl-terminated Dendrimers: Design for Applications in Molecular Electronics, Molecular Recognition and Catalysis

This micro-review shows how a simple but powerful organometallic C–H activation could be made very useful for the construction of a large variety of stars, dendritic cores, dendrons and dendrimers of variable sizes including giant dendrimers and gold-nanoparticle-cored dendrimers. The synthesis of ferrocenyl-terminated dendrimers was then achieved by reactions of chlorocarbonylferrocene with polyamino dendrimers, ferrocenylsilylation of polyolefin dendrons and dendrimers and “click” reactions of ferrocenyl acetylene with azido-terminated dendrimers. The functions of these metallodendrimers include molecular electronics (molecular batteries), molecular redox recognition and sensing and catalysis using dendritic stabilization of nanoparticle catalysts.     

Synthesis of glucose-sensitive self-assembled films and their application in controlled drug delivery

Hydrogen-bonded layer-by-layer assembled films from poly(vinyl pyrrolidone) and poly(acrylic acid) were crosslinked with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and ethylenediamine, and modified with 3-aminophenylboronic acid and isopropylamine simultaneously. The resultant films present pH- and thermosensitive swelling behaviors. Furthermore, the swelling of the films is enhanced when saccharides, such as glucose or fructose, is present in the solution. Alizarin Red S (ARS) was used as a model drug to study the drug release behavior of the films. The loading amount of ARS increases with increasing ARS concentration, which binds covalently with the phenylboronic acid groups in the film. The release of ARS is faster in the presence of glucose, which competes with ARS for binding sites in the film. The novel multistimuli-sensitive films may find applications in self-regulated insulin delivery.     

手性树枝状大分子催化剂的合成及其在不对称催化中的应用进展

根据手性催化剂活性位点在树枝状大分子（Dendrimer）中位置的不同,综述了催化活性位点分别位于Dendrimer核心和外围以及聚合物固载化的手性Dendrimer催化剂的合成及其在不对称氢化、不对称氢转移、不对称Michael加成、硼烷对酮的不对称还原、不对称醇醛缩合反应、不对称Diels-Alder反应等不对称催化反应中的应用,重点论述了树枝状结构及代数对手性催化剂的活性、对映选择性及循环利用的影响,并对开发活性、选择性和稳定性更高的可回收手性Dendrimer催化剂前景进行展望。     

Polyphophazenes as anti-cancer drug carriers: From synthesis to application

Currently, most of administered anti-cancer drugs are low molecular weight compounds (as compare to polymers) and hydrophobic in nature. Such small molecular anti-cancer drugs possess fast clearance rate from the blood circulating system and have toxic side effects. Poly(organophosphazenes) have wide range of biomedical applications owing good biocompatibility, sustainability and degradability into non-toxic by-products. So, in this review, we have carefully selected such poly(organophosphazenes), which proved to be good anti-cancer drug carriers because of overcoming crucial issues related to the administration of anti-cancer drugs i.e. poor hydrophilicity, lack of cancer cells specificity, and fast clearance rate from blood circulating system. Thence, the main focus of this review is to highlight the advancement that have been achieved in the synthesis of poly(organophosphazenes) and their application in anti-cancer drug delivery system (DDS).     

Poly(ethoxytriethyleneglycol acrylate) cryogels as novel sustained drug release systems for oral application

Novel temperature sensitive cryogels of poly(ethoxytriethyleneglycol acrylate) (PETEGA), with in situ entrapped active substance, are synthesized employing the UV irradiation technique and tested as matrix for controlled release of the hydrophilic drug verapamil hydrochloride. PETEGA cryogels are non-toxic materials and, due to the macroporous structure, exhibit a reversible, ultra-rapid volume phase transition at temperature ca. 31 °C. Carriers based on PETEGA cryogels possess sustained release of verapamil hydrochloride over a period of more than 8 h, which is attributed to the hydrophobic state of the polymer network at physiological temperature and the method of drug immobilization. Drug release characteristics of PETEGA cryogels are compared with another cryogel systems, based on polyacrylamide (PAAm), poly(N-isopropylacrylamide) (PNIPAAm) and poly(2-hydroxyethyl methacrylate) (PHEMA), obtained via the same method.