Fig 2. Detection of non-differentiated, glycocalyx-free enterocytes by particulate contrast agents.
Exposure of the apical surface of variably differentiated areas of the human colon carcinoma cell line Caco-2BBe2 with CTB-coated (A-C) or LTB-coated (D-F) microparticles. (A, D) Phase contrast. (B, E) Visualization of the carbohydrate coat on partially differentiated cells with the fluorescein-labeled (green) lectin ECA (B) or UEA I (E). (C, F) Binding of CTB- (C) or LTB- (F) coated microparticles (red) to the membrane receptor ganglioside GM1 in glycocalyx-free areas of non-differentiated cells. Scale bar = 50 μm (A-C) respectively 200 μm (D-F). (G) Schematic illustration of the aspired in vivo detection of mucosal neoplasia. To detect CRC a particulate contrast agent (red) coated with a ligand for a cell membrane receptor (blue) can be used. In the intestine, the particles should bind selectively to the membrane receptors of anomalously differentiated cells that lack a glycocalyx (green). The particle-stained neoplasia can be visualized by appropriate imaging modalities.