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Updated: Oct 14, 2025

Preparing a 68Ga-labeled Arginine Glycine Aspartate RGD-peptide for Angiogenesis
Published on: January 7, 2019
Influence of Linker Molecules in Hexavalent RGD Peptides on Their Multivalent Interactions with Integrin αvβ3
Yuki Mizuno1,2,3, Kohta Kimura1, Satoru Onoe1
1Laboratory of Physical Chemistry, Showa Pharmaceutical University, Machida 194-8543, Japan.
Abstract:
Multivalent RGD peptides have been used as an excellent targeting vector to integrin αvβ3-positive tumors. However, little attention has been paid to the influence of linker molecules in multivalent RGD peptides on their dissociation kinetics from tumor cells. In this study, we evaluated the dissociation kinetics of 99mTc-labeled hexavalent RGD peptides which have (CH2-CH2-O) (n = 4, [99mTc][Tc(L1)6]+ and n = 12, [99mTc][Tc(L2)6]+) or (DPro-Gly) (n = 1, [99mTc][Tc(L3)6]+; n = 6, [99mTc][Tc(L4)6]+; and n = 9, [99mTc][Tc(L5)6]+) as a linker molecule. The results showed that [99mTc][Tc(L4)6]+ and [99mTc][Tc(L5)6]+ displayed slower dissociation kinetics and [99mTc][Tc(L4)6]+ showed exceptionally high in vitro cellular uptake (203.1 ± 16.7% dose/mg protein) and the highest tumor to blood ratio (138.1 ± 26.3 at 4 h p.i.) in tumor bearing nude mice. These findings indicate that the use of appropriate length of (DPro-Gly) would maximize the binding of multivalent RGD peptides to clustered integrin αvβ3.
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