Introduction: Two-step and three-step pretargeting systems utilizing biotinylated prostate tumor-homing bacteriophage (phage) and (111)In-radiolabeled streptavidin or biotin were developed for use in cancer radioimaging. The in vivo selected prostate carcinoma-specific phage (G1) displaying up to five copies of the peptide IAGLATPGWSHWLAL was the focus of the present study.
Methods: The ability of G1 phage to extravasate and target prostate tumor cells was investigated using immunohistochemistry. G1 phages were biotinylated, streptavidin was conjugated to diethylenetriaminepentaacetic acid (DTPA) and biotin was conjugated to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA). Biodistribution studies and single-photon emission computed tomography (SPECT)/CT imaging of xenografted PC-3 tumors via two-step pretargeted (111)In-labeled streptavidin and three-step pretargeted (111)In-labeled biotin were performed in SCID mice to determine the optimal pretargeting method.
Results: The ability of G1 phage to extravasate the vasculature and bind directly to human PC-3 prostate carcinoma tumor cells in vivo was demonstrated via immunocytochemical analysis. Comparative biodistribution studies of the two-step and three-step pretargeting strategies indicated increased PC-3 human prostate carcinoma tumor uptake in SCID mice of 4.34+/-0.26 %ID g(-1) at 0.5 h postinjection of (111)In-radiolabeled biotin (utilized in a three-step protocol) compared to 0.67+/-0.06 %ID g(-1) at 24 h postinjection of (111)In radiolabeled streptavidin (employed in a two-step protocol). In vivo SPECT/CT imaging of xenografted PC-3 tumors in SCID mice with the three-step pretargeting method was superior to that of the two-step pretargeting method, and, importantly, blocking studies demonstrated specificity of tumor uptake of (111)In-labeled biotin in the three-step pretargeting scheme.
Conclusion: This study demonstrates the use of multivalent bifunctional phage in a three-step pretargeting system for prostate cancer radioimaging.
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http://dx.doi.org/10.1016/j.nucmedbio.2009.04.010 | DOI Listing |
J Nanobiotechnology
March 2024
Theranostics and Translational Research Center, Institute of Clinical Medicine & Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, No.1 Shuaifuyuan, Dongcheng District, Beijing, 100730, China.
Pharmaceutics
February 2024
Department of Pharmacy, University of Genoa, Viale Cembrano 4, 16148 Genova, Italy.
Inflammation is a physiological response to a damaging stimulus but sometimes can be the cause of the onset of neurodegenerative diseases, atherosclerosis, and cancer. These pathologies are characterized by the overexpression of inflammatory markers like endothelial adhesion molecules, such as Vascular Cell Adhesion Molecule-1 (VCAM-1). In the present work, the development of liposomes for therapeutic targeted delivery to inflamed endothelia is described.
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April 2023
UAR 3408, CNRS, CEA, Unicaen, Cyceron, Bd Henri Becquerel, 14074 Caen, France.
Pharmaceutics
July 2021
Department of Pharmacy, University of Genova, viale Cembrano 4, 16148 Genova, Italy.
Atherosclerosis is a chronic progressive disease involving inflammatory events, such as the overexpression of adhesion molecules including the endothelial Vascular Cell Adhesion Molecule-1 (VCAM-1). VCAM-1 is rapidly overexpressed in the first stages of atherosclerosis, thus representing a promising target for early atheroma detection. Two novel Positron Emission Tomography (PET) radiopharmaceuticals (MacroP and NAMP), based on the VCAM-1-binding peptide having sequence VHPKQHRGGSKGC, were synthesized and characterized.
View Article and Find Full Text PDFJ Labelled Comp Radiopharm
September 2021
Radiopharmaceuticals Center, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China.
Amplification pretargeting has the potential to increase the tracer's accumulation in the tumor. This study aimed to develop a three-step amplification pretargeting strategy in nuclear medicine with a polymer conjugated with multiple copies of peptide nuclear acid (PNA). In this study, the tracer F-labeled complementary PNA ( F-cPNA) was prepared by click-chemistry with high radiochemical purity (>99%) and great stability in vitro.
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