02 October 2025 Microvessels - capillaries and post‑capillary venules - are the smallest vessels in the circulation, with a cellular composition and thin-walled structure that enables nutrient exchange, oxygen delivery, waste removal, and immune‑cell trafficking between the blood and surrounding tissue cells. The absence of microvascular function is often cited as a major bottleneck of in vitro preclinical models, leading to tissue necrosis and limiting physiological releva
