albuminrelated

Albumin-related is an adjective used to describe phenomena, processes, or substances connected to albumin, most commonly human serum albumin (HSA). Albumin is a single polypeptide protein synthesized by the liver and circulating in blood plasma, where it helps maintain oncotic pressure and serves as a carrier for many endogenous and exogenous ligands.

Human serum albumin is the major plasma protein, representing roughly 60% of total plasma protein and typically present at concentrations of about 3.5 to 5.0 g/dL (35–50 g/L). It binds a wide range of ligands, including free fatty acids, bilirubin, metal ions, hormones, and numerous drugs, with two principal binding regions known as Sudlow sites I and II. The molecule also participates in antioxidant defense via a free thiol group at cysteine-34 and contributes to the transport and disposition of substances in the circulatory system. Its half-life in humans is about 19 to 21 days and it is predominantly catabolized in tissues.

Clinically, decreased albumin levels (hypoalbuminemia) arise from malnutrition, liver disease, nephrotic syndrome, or systemic inflammation, and can contribute to edema and ascites. Albuminuria, the presence of albumin in urine, is a marker of kidney damage and is used in assessing renal disease and cardiovascular risk. Laboratory assessment of albumin is routinely performed in serum using colorimetric assays, with reference ranges roughly 3.5–5.0 g/dL, though values may be affected by inflammation and hydration.

In medicine and research, albumin serves as a drug carrier and platform for therapeutic delivery, including albumin-binding drugs and fusion proteins that exploit a longer circulatory half-life. Albumin-based formulations and nanoparticles are explored for drug delivery and imaging, while studies address oxidative modifications and glycation of albumin in chronic diseases.

See also: Human serum albumin; Hypoalbuminemia; Albuminuria; Drug delivery systems based on albumin.