The effects of Pluronic block copolymers on the aggregation state of nystatin
The effects of Pluronic block copolymers on the aggregation state of nystatin
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DOI：
10.1016/j.jconrel.2003.11.003
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发表时间：
2004-03-05
影响因子：
10.8
通讯作者：
Kwon, GS
中科院分区：
文献类型：
--
作者：
Croy, SR;Kwon, GS
本工作的目的是表征嵌段共聚物的组成对制霉菌素的聚集状态的影响在Pluxonic胶束的存在。采用动态光散射法测定制霉菌素的临界聚集浓度（CACs）。37℃时，制霉菌素在磷酸盐缓冲盐水中的CAC为20 μ m。Pluronics的加入显著提高制霉菌素的CAC，在37℃的温度下达到bb50 - 350 muM。CAC值与Pluronic疏水块的大小成正比，与Pluronic临界胶束化浓度（CMC）成反比。可以预见的是，Pluronic浓度和温度的升高显示了CACs的增加。制霉菌素荧光法测定制霉菌素胶束-水分配系数(P)。计算F68、F98、P105、F127 37°c时制霉菌素的P值分别为15、21、73、79。用芘荧光测定的Pluronic胶束核极性实验表明，极性随疏水块长度和温度的增加而降低。因此，Pluronics存在下制霉菌素CACs与分割系数直接相关，与核极性成反比。这些结果表明，溶液中胶束的数量是Pluronics溶解制霉菌素的主要因素。(C) 2004 Elsevier B.V.版权所有
The purpose of this work was to characterize the effect of block copolymer composition on the aggregation state of nystatin in the presence of Pluxonic micelles. The critical aggregation concentrations (CACs) of nystatin were determined by dynamic light scattering (DLS). The CAC of nystatin in phosphate-buffered saline was 20 muM at 37 degreesC. Addition of Pluronics significantly increased the CAC of nystatin up to >350 muM at 37 degreesC at the concentrations studied. The CAC values corresponded directly to the size of the Pluronic hydrophobic blocks, and inversely with Pluronic critical micellization concentration (CMC). Predictably, increasing Pluronic concentration and temperature revealed increases in CACs. The micelle-water partition coefficient (P) of nystatin was determined by nystatin fluorescence. The P for nystatin at 37 degreesC was calculated in F68, F98, P105, and F127 to be 15, 21, 73, and 79, respectively. Pluronic micelle core polarity experiments, determined by pyrene fluorescence, revealed decreased polarity with increasing hydrophobic block length and temperature. Thus, nystatin CACs in the presence of Pluronics correlated directly with the partition coefficients, and inversely with core polarity. These results point to the number of micelles in solution as the primary factor responsible for nystatin solubilization by Pluronics. (C) 2004 Elsevier B.V. All rights reserved.