Cellular uptake

Cellular uptake refers to the broad set of mechanisms by which cells absorb molecules, particles, or ions from their external environment[1][2][3]. These mechanisms include passive diffusion, active transport (requiring energy expenditure), endocytosis (including clathrin-mediated, caveolin-mediated, and clathrin/caveolin-independent forms), phagocytosis (engulfment of large particles by immune cells), macropinocytosis (nonspecific engulfment of extracellular fluid), and transporter-specific uptake across the plasma membrane[1][2][3][4]. The selective permeability of the cell membrane, along with the presence and activity of various transport proteins, governs the specificity and regulation of uptake[1]. "Cellular uptake" is not a discrete molecular entity but a collective term for multiple transport processes that underlie essential physiological functions, including nutrient acquisition, cell signaling (via receptor-mediated endocytosis), immune defense, and the internalization of drugs, toxins, and nanoparticles[2][3]. Disruption or alteration of these pathways is implicated in diseases such as cancer, infection, and metabolic disorders. In biotechnology and medicine, understanding cellular uptake is crucial for optimizing therapeutic drug delivery and nanomedicine strategies[2][3][4]. Cellular uptake is not a specific therapeutic target, but a fundamental cell biology concept describing various mechanisms for molecules to enter cells. It cannot be mapped to a receptor, transporter, or enzyme entity and should not be referenced as a canonical drug target.

Other names

Cellular absorptionCell internalizationMolecular uptake