Journal: Acta Pharmaceutica Sinica. B
Article Title: Enhanced radiotheranostic targeting of integrin α 5 β 1 with PEGylation-enabled peptide multidisplay platform (PEGibody): A strategy for prolonged tumor retention with fast blood clearance
doi: 10.1016/j.apsb.2024.07.006
Figure Lengend Snippet: In vitro binding affinity and stability studies of [ 64 Cu]QM-2301, [ 64 Cu]QM-2302, and [ 64 Cu]QM-2303. (A) SPR sensorgrams demonstrating the binding affinity of QM-2301, QM-2302, and QM-2303 for human integrin α 5 β 1 in a concentration-dependent manner. (B) The equilibrium dissociation constant ( Κ D ) of each peptide was calculated based on SPR measurements. The K D values of each precursor are shown. (C, D) Schematic diagram of the binding patterns of [ 64 Cu]QM-2301, [ 64 Cu]QM-2302 (C), and [ 64 Cu]QM-2303 (D) to integrin α 5 β 1. Monomeric [ 64 Cu]QM-2301, and [ 64 Cu]QM-2302 bind to receptors in a single-network pattern. For [ 64 Cu]QM-2303, the PEGibody-based radiotracer, one PEGibody can bind to more than two integrin α 5 β 1 receptors, exhibiting better binding affinity. (E, F) The expression of integrin α 5 β 1 in B16F10 cells was analyzed by flow cytometry (E) and Western blotting (F). For flow cytometry assays, an anti-integrin α 5 + β 1 antibody was used. For Western blot assays, integrin α 5 (∼150 kDa) and integrin β 1 (∼138 kDa) were examined using two antibodies. (G) The stability of [ 64 Cu]QM-2301, [ 64 Cu]QM-2302, and [ 64 Cu]QM-2303 after coincubation with mouse serum within 1 h, as indicated by radio-HPLC. (H) I n vitro cell uptake of [ 64 Cu]QM-2301, [ 64 Cu]QM-2302, and [ 64 Cu]QM-2303 (750 KBq/mL) when incubated with B16F10 cells for different time period. (I) IC 50 of [ 64 Cu]QM-2301, [ 64 Cu]QM-2302, and [ 64 Cu]QM-2303 when inhibited with antibodies at different concentrations. ∗ P < 0.05, ∗∗ P < 0.01. All the quantitative experiments were performed independently at least three times (data are the mean ± SD, n = 3).
Article Snippet: Recombinant human integrin α 5 β 1 (alpha 5 beta 1, HY-P77718, MCE, NJ, USA) was immobilized on a CM5 sensor chip using a standard amine coupling kit at a temperature of 25 °C.
Techniques: In Vitro, Binding Assay, Concentration Assay, Expressing, Flow Cytometry, Western Blot, Incubation