Multiple endogenous receptors and cellular uptake pathways

Multiple endogenous receptors and cellular uptake pathways is a collective term used in pharmacology and regulatory science to describe the diverse biological mechanisms through which molecules, particularly imaging agents and complex drug delivery systems, enter cells (FDA Global Substance Registration System). This designation does not refer to a single molecular entity but rather encompasses a variety of internalization processes such as clathrin-mediated endocytosis, caveolae-dependent uptake, and fluid-phase pinocytosis (Nature Reviews Molecular Cell Biology, 2009). These pathways are fundamental to cellular physiology, facilitating the ingestion of nutrients, the regulation of cell-surface signaling receptors, and the maintenance of membrane homeostasis (Molecular Biology of the Cell, 4th ed.). In a therapeutic context, these pathways are often exploited to deliver macromolecular drugs or nanoparticles into target tissues, though they can also be utilized by pathogens to gain entry into host cells (Journal of Controlled Release, 2014). Because this term represents a functional grouping of various proteins and lipid-mediated processes rather than a discrete receptor or enzyme, it is typically used when a drug's specific molecular target is either unknown or involves a broad spectrum of cellular entry points.

Other names

Endogenous receptorsCellular uptake mechanismsReceptor-mediated endocytosis pathwaysNon-specific uptake pathways

Internalization of substances through various cell-surface interactions and endocytic processes including clathrin-mediated, caveolae-mediated, and macropinocytotic pathways.