Molecular and Cellular Biosciences, School of Life Sciences, Arizona State University, Tempe, AZ, 85287-4501, USA.
Adv Exp Med Biol. 2014;811:55-72. doi: 10.1007/978-94-017-8739-0_4.
Nanoparticles hold great promise in cell biology and medicine due to the inherent physico-chemical properties when these materials are synthesized on the nanoscale. Moreover, their small size, and the ability to functionalize the outer nanoparticle surface makes them an ideal vector suited to traverse a number of physical barriers in the human body. While nanoparticles hold great promise for applications in cell biology and medicine, their downfall is the toxicity that accompanies exposure to biological systems. This chapter focuses on exposure via the oral route since nanomaterials are being engineered to act as carriers for drugs, contrast agents for specialized imaging techniques, as well as ingested pigments approved by regulatory agencies for human food products. After these nanomaterials are ingested they have the potential to interact with a number of biologically significant tissues, one of which is the epithelium of the small intestine. Within the small intestine exists enterocytes whose principal function is nutrient absorption. The absorptive process is aided by microvilli that act to increase the surface area of the epithelium. Dense arrays of microvilli, referred to as the brush border, have recently been shown to undergo disruption as a consequence of exposure to nanomaterials. This chapter aims to set the stage for detailed mechanistic studies at the cell biology level concerning this newly emerging nanotoxicity research paradigm, as the underlying structural characterization responsible for the existence of microvilli have been elucidated.
由于这些材料在纳米尺度上合成时具有固有物理化学性质，因此纳米粒子在细胞生物学和医学中具有很大的应用前景。此外，它们的体积小，并且能够对外层纳米粒子表面进行功能化，这使它们成为一种理想的载体，适合穿越人体中的许多物理屏障。虽然纳米粒子在细胞生物学和医学中的应用前景广阔，但它们的缺点是暴露于生物系统时会伴随毒性。本章重点关注通过口服途径的暴露，因为纳米材料被设计为药物载体、专门成像技术的对比剂，以及被监管机构批准用于人类食品的食用色素。这些纳米材料被摄入后，它们有可能与许多具有生物学意义的组织相互作用，其中之一是小肠的上皮细胞。在小肠内，存在着肠细胞，其主要功能是吸收营养物质。吸收过程得到微绒毛的辅助，微绒毛的作用是增加上皮细胞的表面积。被称为刷状缘的密集微绒毛阵列最近被证明由于暴露于纳米材料而受到破坏。本章旨在为细胞生物学水平的详细机制研究奠定基础，涉及这一新出现的纳米毒性研究范例，因为负责微绒毛存在的基础结构特征已经阐明。
