Figure 1. Design and characterization of conjugates using nanoscale dendrimers as scaffolds assembling multiple antibodies against carbohydrate antigen Sialyl Lewis X (aSlex) for capturing and regulating the colon cancer HT29 cells.

(A), Two synthetic procedures of aSlex-conjugated dendrimers with FITC labeling by sequential conjugation of the completely carboxylated PAMAM dendrimers with FITC and aSlex (a–c–e) or by sequential conjugation of the partially carboxylated PAMAM dendrimers with aSlex and IgG/IgM-FITC (b–d–f). 1, PAMAM with amine groups; 2, PAMAM with the partially carboxylated groups; 3, PAMAM with the completely carboxylated groups; 4, PAMAM linked with FITC; 5, PAMAM conjugated with primary antibody; 6, FITC-labeled PAMAM conjugated with antibody; 7, Primary antibody-coated PAMAM conjugated with FITC-labeled secondary antibody. (B), UV/Vis spectra of dendrimers, aSlex and dendrimers-aSlex conjugates. (C), Fluorescence images of FITC labeled G6-aSlex conjugates in solution obtained by a laser confocal microscope in the channel of Alexa Fluor 488. (D), Tapping mode AFM image of G6-5aSlex conjugate (0.001% w/w) deposited on mica. The image was obtained by operating the microscope in a L state. Scan size was 2 μm. (E), Schematic view of the CTCs (HT29 cells) capture and regulation process by using aSlex-coated dendrimer conjugates.