Photosensitization of albumin: a potential approach to modulate drug delivery into abnormal cells.

分子交换，包括系统给药的药物，在组织和组织之间的交换。 血管系统依赖于血清白蛋白穿过毛细血管内腔的内皮细胞层。 人血清白蛋白（HSA）的摄取可以通过蛋白质与特定天然受体的对接而发生 （gp60）在内皮细胞的表面。然而，另一类受体（gp18和gp30）已经被发现。 发现了这类受体结合已经结构修饰的HSA。据信这些 受体作为清除剂清除未正确折叠的HSA。它们存在于其他生物的表面 但是已经发现它们在一些癌细胞中过表达， 三阴性乳腺癌假设HSA与其受体对接的基本范式 依赖于结构互补性，两类受体的存在开启了 通过调节HSA的结构来靶向两种不同的细胞类型。该项目建议调查 光敏化作为调节HSA结构并诱导与gp18优先结合的方法 或GP30受体，从而提供了一种将白蛋白导向靶向三阴性乳腺癌细胞的方法。以来 除其他外，HSA携带化疗药物，所提出的方法可以应用于改善 抗癌治疗的选择性。基于PI小组用球形粒子获得的结果， 蛋白质，所提出的活动的工作假设是，光敏化的HSA，介导的 卟啉配体引起HSA结构的局部改变，并通过这样做，抑制与天然配体的对接。 GP 60受体，同时促进与GP 18和GP 30受体的结合。将诱导HSA的光敏化 在体外，在体内测试之前，从而使对细胞的不利影响最小化。建议的项目包括 使用体外和体内实验方法结合计算模拟来表征 结构的变化，并研究这些变化如何影响其对接的受体上内皮细胞， 以及癌细胞。还将使用模型蛋白（骨粘连蛋白）研究与受体的对接 其被假定与天然gp60受体共享用于HSA对接的共同基序。总的来说， 证明HSA与膜受体的对接可以通过光学方法进行修饰， 在药物输送的管理中提供潜在的重要影响。

The exchange of molecules, including systemically-administered pharmaceuticals, between tissues and the vasculature depends on serum albumin crossing the endothelial cell layer that lines the lumen of the capillaries. Uptake of human serum albumin (HSA) can occur through the docking of the protein to specific native receptors (gp60) at the surface of the endothelial cells. However, another class of receptors (gp18 and gp30) has been discovered. This class of receptors binds HSA that has been structurally modified. It is believed that these receptor act as scavenger to eliminate HSA that is not properly folded. They are found at the surface of other cell types such as fibroblasts but it has been discovered that they are overexpressed in some cancer cells such as triple negative breast cancer. Assuming the fundamental paradigm that docking of HSA to its receptors depends on structure complementarity, the existence of the two classes of receptors opens the possibility of targeting two different cell types by modulating the structure of HSA. The project proposes to investigate photosensitization as an approach to modulate the structure of HSA and induce the preferential binding to gp18 or gp30 receptor thus providing a method to direct albumin to target triple negative breast cancer cells. Since HSA carries, among others, chemotherapeutic medications, the proposed approach could apply to an improve selectivity of anticancer treatments. Based on results that the group of the PI has obtained with globular proteins, the working hypothesis of the proposed activity is that photosensitization of HSA, mediated by a porphyrin ligand, causes local alteration of the structure of HSA and by doing so, suppress docking to the native gp60 receptor while promoting binding to the gp18 and gp30 receptors. Photosensitization of HSA will be induced in vitro, prior to the testing in vivo, thus minimizing adverse effects on cells. The proposed project includes the use of experimental in vitro and in vivo methods combined with computational simulations to characterize the structural changes of HSA and investigate how these changes affect its docking to receptors on endothelial as well as cancer cells. The docking to the receptor will be also investigated using a model protein (osteonectin) which is postulated to share with the native gp60 receptor a common motif for the docking of HSA. Overall, demonstrating that the docking of HSA to membrane receptors can be modified through optical methods, would provide potentially important repercussion in the management of drug delivery.