vesselspecificity

Vessel specificity refers to the degree to which a molecule, therapy, imaging agent, or biological process preferentially interacts with or affects particular blood vessels or vascular beds. It encompasses targeting to specific vascular tissues (for example, arteries, veins, or capillaries) and to organ- or tissue-specific endothelium, as well as selective modulation of vascular functions such as permeability, flow, or receptor signaling within defined vascular segments.

The determinants of vessel specificity include molecular recognition by endothelial receptors, adhesion molecules, or transporters that are enriched in certain vascular beds; physical properties of the vasculature such as permeability and shear stress; and structural differences in the endothelium, pericyte coverage, and basement membrane. Pharmacokinetic factors, particle size and surface chemistry in nanomedicine, and the presence of locally expressed ligands influence whether a compound accumulates in a target vessel.

Assessment of vessel specificity commonly relies on biodistribution and imaging studies using labeled compounds, as well as in vitro assays with endothelial cells derived from different vascular beds. Techniques such as positron emission tomography, magnetic resonance imaging, and fluorescence imaging can reveal preferential localization to specific vessels or tissues.

Applications of vessel specificity include targeted drug delivery to tumor vasculature or inflamed tissues, vascular imaging contrast agents that highlight particular beds, and therapies aimed at modulating barrier function in the brain or other organs. Challenges include heterogeneity across individuals, dynamic changes in the vasculature, potential off-target effects, and safety considerations related to receptor-directed strategies. See also vascular targeting, organ-specific endothelium, and targeted drug delivery.