Bicyclic peptides conjugated to an albumin-binding tag diffuse efficiently into solid tumors.

Monoclonal antibodies have long in vivo half-lives and reach high concentrations in tumors but cannot access all regions in the tissue, whereas smaller ligands such as peptides distribute better but are limited by low concentrations due to fast renal clearance. A potential solution to this problem might be offered by peptide-based ligands that are conjugated to an albumin-binding tag, and thus have a long plasma half-life. Herein, we tested if a small ligand based on a bicyclic peptide (1.

A tissue-engineered model of the intestinal lacteal for evaluating lipid transport by lymphatics.

Lacteals are the entry point of all dietary lipids into the circulation, yet little is known about the active regulation of lipid uptake by these lymphatic vessels, and there lacks in vitro models to study the lacteal-enterocyte interface. We describe an in vitro model of the human intestinal microenvironment containing differentiated Caco-2 cells and lymphatic endothelial cells (LECs). We characterize the model for fatty acid, lipoprotein, albumin, and dextran transport, and compare to qualitative uptake of fatty acids into lacteals in vivo.