Department of Experimental Medicine, Faculty of Medicine, Universidad Nacional Autónoma de México, Hospital General de México, México D.F., Mexico.
Curr Drug Metab. 2013 Jun;14(5):540-6. doi: 10.2174/13892002113149990011.
The microcirculation presents functional organic structures in the range of 1-100 micrometers, commensurate with the upper end of nanotechnology constructs. When devices are designed and deployed to deliver treatment via the circulation they ultimately contend with the smallest dimensions of both healthy and impaired microvessels, particularly the capillary system whose ability to sustain the tissue is assessed by measuring "functional capillary density" (FCD). FCD is directly determined by hydrostatic and osmotic pressures and indirectly by the effect of cardiovascular regulators, particularly the bioavailability of nitric oxide (NO) resulting from fluid mechanical effects and transport in the submicroscopic cell free plasma layer (CFL) located between blood and microvascular wall. Macromolecules using colloids as templates that are surface decorated with polyethylene glycol (PEG) become immuno-invisible and can be introduced into the circulation to manipulate the NO environment in blood and the endothelium. PEG-albumin is a class of molecules with novel plasma expansion properties that directly interacts with the microcirculation via CFL related effects. The principal application of this technology is in transfusion medicine and the plasma expanders used to treat blood losses and concomitant effects on microvascular function due to related acute inflammatory conditions and ischemia.
微循环呈现出 1-100 微米范围内的功能性有机结构，与纳米技术结构的上限相当。当设备被设计并部署用于通过循环进行治疗时，它们最终会与健康和受损微血管的最小尺寸相抗衡，特别是毛细血管系统，其维持组织的能力通过测量“功能性毛细血管密度”（FCD）来评估。FCD 直接由静水压力和渗透压决定，间接由心血管调节剂的作用决定，特别是一氧化氮（NO）的生物利用度，这是由流体力学效应和位于血液和微血管壁之间的亚微观无细胞血浆层（CFL）中的运输产生的。使用胶体作为模板并在表面修饰聚乙二醇（PEG）的大分子变得免疫不可见，可以引入循环中以操纵血液中的 NO 环境和内皮细胞。PEG-白蛋白是一类具有新型血浆扩张特性的分子，通过与 CFL 相关的作用直接与微循环相互作用。该技术的主要应用是在输血医学和用于治疗因相关急性炎症和缺血引起的血液损失和对微血管功能影响的血浆扩张剂中。
