11C-radiolabeled aptamer for imaging of tumors and metastases using positron emission tomography- computed tomography

Abstract

Identification of primary tumors and metastasis sites is an essential step in cancer diagnostics and the following treatment. Positron emission tomography-computed tomography (PET/CT) is one of the most reliable methods for scanning the whole organism for malignancies. In this work, we synthesized an 11 C-labeled oligonucleotide primer and hybridized it to an anti-cancer DNA aptamer. The 11 C-aptamer was applied for in vivo imaging of Ehrlich ascites carcinoma and its metastases in mice using PET/CT. The imaging experiments with the 11 C-aptamer determined very small primary and secondary tumors of 3 mm 2 and less. We also compared 11 C imaging with the standard radiotracer, 2-deoxy-2-[fluorine-18]fluoro-Dglucose ( 18 F-FDG), and found better selectivity of the 11 C-aptamer to metastatic lesions in the metabolically active organs than 18 F-FDG. 11 C radionuclide with an ultra-short (20.38 min) half-life is considered safest for PET/CT imaging and does not cause false-positive results in heart imaging. Its combination with aptamers gives us high-specificity and high-contrast imaging of cancer cells and can be applied for PET/CT-guided drug delivery in cancer therapies.

Towards understanding the triggering of the malignant cell death in high-efficiency magneto-mechanical anticancer therapy

“…In a simplified case of MNP binding to a membrane in its specific area, limited by the size of the aptamer (within 10 nm [117]), as well as a fragment of fibronectin fiber and integrin, the character of particle motion is an arc, the length of which is limited by the contact condition membrane particle on the left and right, as shown in figure 1. It is also important to note that MNP deforms the membrane at the site of contact with it and, during rotation, creates a moment of force that has a vertical projection, which is applied to the transmembrane protein integrin (or to another membrane element with which a connection can selectively occur)…”

Engineered aptamers for molecular imaging

“…206 Since then, various radiolabeling strategies for SPECT or PET have been developed, including the use of isotopes, such as 99m Tc, 111 In, and 123 I for SPECT, and 11 C, 18 F, 68 Ga, and 64 Cu for PET. [207][208][209][210][211] Bohrmann et al developed an aptamer-targeted nanoplatform based on hyperbranched polyglycerol (HPG) to improve the stability and applicability of aptamer. 210 Their study demonstrated that the Sgc8 aptamer exhibited highly specic binding to various cancer cells and displayed good binding characteristics and biocompatibility in vitro, with an extended half-life.…”

Aptamers used for molecular imaging and theranostics - recent developments

“…Ozerskaya et al . took an interesting approach for 11 C labeling of AS-14 aptamer for PET imaging of Ehrlich ascites carcinoma 93 . Instead of directly labeling the aptamer, a 11 C-labeled complementary primer was hybridized to AS-14.…”