Dendrimers as Drug Carriers: Dynamics of PEGylated and Methotrexate-Loaded Dendrimers in Aqueous Solution
Dendrimers as Drug Carriers: Dynamics of PEGylated and Methotrexate-Loaded Dendrimers in Aqueous Solution
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DOI：
10.1021/ma902670q
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发表时间：
2010-03-23
期刊：
影响因子：
5.5
通讯作者：
Mijovic, Jovan
中科院分区：
文献类型：
--
作者：
Natali, Sanja;Mijovic, Jovan
用宽带介电弛豫谱(DRS)研究了聚乙二醇化树枝状大分子、聚乙二醇化树枝状大分子、甲氨蝶呤和聚乙二醇化载药树枝状大分子的水溶液动力学。在所有体系中观察到两个介电弥散，并对其分子起源进行了解释。低频过程的总活化能为52.2kJ/mol，可归因于冰中的运动。较高频率的过程是Cole-Cole类型的，并被分配给聚乙二醇酯和甲氨蝶呤分子周围的结合水。考察了平均聚乙二醇链数目和平均包裹甲氨蝶呤分子数的影响。我们的结果表明，动力学与这些数无关，但是络合物组成的强函数。描述了所有弛豫过程的光谱特性和温度依赖性。
An investigation of the dynamics of aqueous solutions of PEG, PEGylated dendrimers, methotrexate, and PEGylated and drug (methotrexate)-loaded dendrimers was carried out with broadband dielectric relaxation spectroscopy (DRS). Two dielectric dispersions were observed in all systems, and the explanation of their molecular origin was offered. The lower frequency process, characterized by ail activation energy of 52.2 kJ/mol, was attributed to motions in ice. The higher frequency process is of the Cole-Cole type and is assigned to bound water around PEG and methotrexate molecules. Theeffect of the average number of attached PEG chains and the average number of encapsulated methotrexate molecules was probed. Our results indicate that the dynamics arc independent of these numbers but are a strong function of the composition of the complex. Spectral characteristics and temperature dependence of all relaxation processes are described.