Purpose

The study is inspired by the fact that intravenous administration of 2-hydroxypropyl-beta-cyclodextrins (HP-β-CD) in rats leads to a rapid decrease in plasma cholesterol levels. Further, HP-β-CD being more water soluble than native β-CD, HP-β-CD forms soluble complex with cholesterol and higher affinity of cholesterol towards HP-β-CD than native β-CD leads to increase sensitivity. Hence, present work reports potential use of HP-β-CD as a chemosensor to detect cholesterol aided with l-tryptophan (l-Trp) as a fluorescence probe. The purpose of the study is to develop fast, cost-effective, and high throughput fluorescence-based chemosensor as convenient point-of-care diagnostic method for cholesterol detection.

Methods

The host-guest interaction of l-Trp with HP-β-CD was elaborately studied using characterization techniques such as FT-IR, NMR, and DSC. Time and concentration dependent interactions were studied to determine the stoichiometry of molecular inclusion complexes of HP-β-CD with l-Trp. Further, the inclusion complex of HP-β-CD with l-tryptophan is explored to detect cholesterol based on the competitive displacement phenomenon and further explored for detecting different concentrations of cholesterol.

Results

Fluorescence spectroscopic data revealed that HP-β-CD served as a quencher for l-Trp. Also, promising results of the displacement assay proved that the fluorescence of l-Trp was quenched by HP-β-CD followed by increase in fluorescence signals in quantitative relation with cholesterol as it replaces l-Trp from the HP-β-CD host.

Conclusion

The present investigation is a proof-of-concept that proves the potential of HP-β-CD with l-Trp as a novel fluorescence–based technique for cholesterol detection which is developed using competitive host–guest interaction.

中文翻译：

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羟丙基-β-环糊精与1-色氨酸的包合物作为荧光探针基于胆固醇的检测

目的

该研究受到以下事实的启发：在大鼠中静脉内注射2-羟丙基-β-环糊精（HP-β-CD）会导致血浆胆固醇水平快速下降。此外，HP-β-CD比天然β-CD更易溶于水，HP-β-CD与胆固醇形成可溶性复合物，并且胆固醇对HP-β-CD的亲和力高于天然β-CD，从而导致敏感性增加。因此，目前的工作报告潜在的使用HP-β-CD作为化学传感器来检测胆固醇与辅助升色氨酸（升-Trp）作为荧光探针。该研究的目的是开发快速，具有成本效益和高通量的基于荧光的化学传感器作为胆固醇检测的便捷即时诊断方法。

方法

使用诸如FT-IR，NMR和DSC等表征技术，精心研究了1 -Trp与HP-β-CD的宿主-客体相互作用。研究了时间和浓度依赖性相互作用，以确定HP-β-CD与1 - Trp的分子包合物的化学计量。此外，基于竞争性置换现象，探索了HP-β-CD与1-色氨酸的包合物，以检测胆固醇，并进一步探索了检测不同浓度的胆固醇。

结果

荧光光谱数据显示HP-β-CD充当1- Trp的淬灭剂。此外，置换测定可喜的成果证明，荧光升-Trp由HP-β-CD淬火，随后在与胆固醇的定量关系荧光信号的增加，因为它取代升从HP-β-CD主机-色氨酸。

结论

本研究是一种概念证明，证明了HP-β-CD与1 - Trp的潜力，这是一种利用竞争性宿主-客体相互作用开发的基于荧光的胆固醇检测新技术。