99mTc-labeled single-domain antibody EG2 in targeting epidermal growth factor receptor

Abstract

This study demonstrated that sdAb EG2 can effectively target EGFR in vitro and in vivo in tumors, suggesting that it could be used as a molecular probe for EGFR detection.

99mTc‐labeled tetramer and pentamer of single‐domain antibody for targeting epidermal growth factor receptor in xenografted tumors

“…The radioactivity accumulation of 99m Tc-EG2 in blood was 1.60 ± 0.13, 0.67 ± 0.06, 0.94 ± 0.10% ID/g at 1, 3, and 6 h after probe injection, indicating that it could be removed rapidly from the blood; the A431 tumor uptake of 99m Tc-EG2 was 1.73 ± 0.16, 2.71 ± 0.45, and 1.64 ± 0.38% ID/g at 1, 3, and 6 h post-injection, respectively. 23 Because of relatively high molecular weight, the half-life of 99m Tc-EG2-COMP in the blood was longer than that of 99m Tc-EG2 (6-16 h). Compared with 99m Tc-EG2, the uptake of 99m Tc-EG2-COMP by A431 was greater with 6.96 ± 1.23% ID/g at 6 h post-injection; and the tumor uptake remained visible for 24 h. The main excretion pathway of 99m Tc-EG2-COMP, different from that of 99m Tc-EG2, is the liver, and we attribute this characteristic to the higher molecular weight of EG2-COMP (>60 kDa).…”

Radioimmunoimaging of 125I‑labeled anti‑CD93 monoclonal antibodies in a xenograft model of non‑small cell lung cancer

“…The most common application to date has been the imaging of overexpressed antigen-associated tumors; the radiolabeled antibody of the human epidermal growth factor receptors (HER1, HER2 and HER3) have been widely used in breast cancer, gastric cancer and NSCLC (11,12). Compared with traditional imaging techniques such as CT or MRI, molecular imaging in nuclear medicine is a non-invasive whole-body scanning modality, and is more suitable for the detection and quantification of the expression levels of target molecules in tumor tissue (13,14). Radioimmunoimaging, which involves the use of a radionuclide in combination with highly specific antibody-based imaging tracers (15), can provide a non-invasive way to evaluate the expression and distribution of molecular targets in vivo , thereby contributing to accurate disease diagnosis and therapeutic and prognostic evaluations.…”

PET Imaging of VCAM-1 Expression and Monitoring Therapy Response in Tumor with a 68Ga-Labeled Single Chain Variable Fragment

“…It may be helpful to identify VCAM-1 overexpression in patients for individualized treatment options. Compared with common applied immunohistochemical analysis, 10 molecular imaging is a noninvasive quantitative examination that may be useful to determine the expression level of VCAM-1. Some studies have reported imaging of VCAM-1, such as monoclonal antibodies conjugated to microbubbles or iron oxide particles.…”

“…It may be helpful to identify VCAM-1 overexpression in patients for individualized treatment options. Compared with common applied immunohistochemical analysis, molecular imaging is a noninvasive quantitative examination that may be useful to determine the expression level of VCAM-1. Some studies have reported imaging of VCAM-1, such as monoclonal antibodies conjugated to microbubbles or iron oxide particles. , To overcome the slow clearance and poor tissue penetration of intact monoclonal antibodies, small antibody fragments and peptides bound to VCAM-1, including single chain variable fragment (scFv) labeled by 99m Tc, nanobodies coupled with 18 F or 99m Tc, , and peptides labeled by 18 F or 99m Tc, , have shown improved image quality.…”