CHARACTERIZING LIPOSOMES FORMED BY MIXTURES OF DPPC OR DODAC W/SUCROSE ESTERS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 蔗糖酯是一类非离子表面活性剂，无毒、皮肤相容、无污染、可生物降解。此外，它们的合成不依赖于石化工业，可以从可再生资源中制备。此外，商业蔗糖酯混合物的表面活性与烷基葡萄糖苷的表面活性相似，烷基葡萄糖苷是一类经常用于膜增溶研究的表面活性剂。因此，蔗糖酯是研究蔗糖与膜相互作用的极具吸引力的候选者，无论是合成的还是生物的。 因此，这项工作的主要目标是评估使用增溶实验来研究非离子表面活性剂与含胆固醇磷脂微囊的相互作用的可行性。使用传统的荧光技术和双光子显微镜，使用Laurdan作为荧光探针，因为它能够感知其微环境极性的变化。这一次，我们感兴趣的是直接观察到通过加入并随后通过添加几个蔗糖酯来增溶DODAC囊泡而促进GUV的GP的变化。 此外，还将进行FCS实验，以确定几种蔗糖单酯的临界胶束浓度，以及聚集数与浓度的关系。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Sucrose esters correspond to a class of non ionic surfactants, non-toxic, skin compatible, non-polluting and biodegradable. Also, their synthesis is not dependent of petrochemical industry and they can be prepared from renewable sources. In addition, the surface-activity described for commercial mixtures of sucrose esters is similar to that of alkyl glucosides, a family of surfactants recurrently employed in membrane solubilization studies. In consequence, sucrose esters are attractive candidates for the study of its interactions with membranes, synthetic and biological. The primary objective of this work was therefore to assess the feasibility of using solubilization experiments to study the interactions of nonionic surfactants with cholesterol-containing phospholipid vesicles. Conventional fluorescence techniques and two-photon microscopy were used, with Laurdan, as a fluorescent probe, because its ability to sense changes in the polarity of its microenvironment. This time we are interested in the direct observation of the changes promoted in the GP of GUVS by the incorporation and subsequent solubilization of DODAC vesicles by the addition of several sucrose esters. Additionally FCS experiments will be carried out in order to determine critical micellar concentrations of several sucrose monoesters, and the dependence of aggregation numbers with concentration.