99mTc-AgNPs-ICG: nanoparticle for hybrid image

Abstract

Introduction: Currently nanotechnology has radically changed the diagnosis of many human pathologies. The aim of this work is to obtain silver nanoparticles for hybrid imaging (99mTc-AgNPs-ICG) having potential clinical imaging applications. Materials and method: We mixed 2 ml of ascorbic acid (1.7x10-4 M), 5 mCi of 99mTcO4- , 2 ml of citric acid (8.0x10-4 M) and 0.5 ml of silver nitrate (2.5x10-3 M). Solution pH was 5, and it was shaken for 20 minutes at 37º C. Afterwards, 2 µL of Indocyanine Green (1.3x10-3 M) was added (99mTc-AgNPs-ICG). Physiochemical properties of the solution were characterized by UV (λ1 = 420 nm, λ2 = 254 nm) and gamma detector. Fluorescence image, particle size and IR spectrum were evaluated. Results: Silver nanoparticles were obtained in aqueous solution a pH of 5. Their pH, color and spectrum were stable for seven days. Furthermore, the principal peak characterized by HPLC, UV and Gamma detector had similar retention times. Its UV spectrum showed an absorption band of 420 nm, which corresponds to the plasmon absorption band of these nanoparticles. The particle size was 46 nm ± 1.5 nm. The IR spectrum showed absorption bands in 3193, 2624, 1596 y 1212 cm-1. Conclusions: We describe for the first time in literature the synthesis of hybrid (radioactive and fluorescent) silver nanoparticles. Their physiochemical properties were characterized, being stable and their labelling was reproducible having potential biomedical applications. Received for review: November 2023. Accepted for publication: February 2024. Correspondence: Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay. Mataojo 2055, P.O. 11400, Montevideo, Uruguay. Tel: (+5982) 5250901/108; fax: (+5982) 5250895. Contact e-mail: pabloc7@gmail.com This article was approved by the Editorial Committee.