Synthesis and In Vivo Evaluation of the Biodistribution of a ¹⁸F-Labeled Conjugate Gold-Nanoparticle-Peptide with Potential Biomedical Application

Abstract

Gold nanoparticles (AuNPs) have been extensively used in biological applications because of their biocompatibility, size, and ease of characterization, as well as an extensive knowledge of their surface chemistry. These features make AuNPs readily exploitable for biomedical applications, including drug delivery and novel diagnostic and therapeutic approaches. In a previous work, we studied ex vivo distribution of the conjugate C(AuNP)-LPFFD for its potential uses in the treatment of Alzheimer's disease. In this study, we covalently labeled the conjugate with [(18)F]-fluorobenzoate to study the in vivo distribution of the AuNP by positron emission tomography (PET). After intravenous administration in rat, the highest concentration of the radiolabeled conjugate was found in the bladder and urine with a lower proportion in the intestine, demonstrating progressive accumulation compatible with biliary excretion of the conjugate. The conjugate also accumulated in the liver and spleen. PET imaging allowed us to study the in vivo biodistribution of the AuNPs in a noninvasive and sensitive way using a reduced number of animals. Our results show that AuNPs can be covalently and radioactively labeled for PET biodistribution studies.

Radiolabeled inorganic nanoparticles for positron emission tomography imaging of cancer: an overview

“…In another study, Guerrero et al reported the radiolabeling of Au nanoparticles with 18 F for use as a PET radiotracer. 50 In this study, N-succinimidyl-4-[ 18 F]-fluorobenzoate was covalently linked to Au nanoparticles conjugated with amphipathic peptide, CLPFFD. In vivo PET imaging in rats after administration of the radiolabeled nanoparticles showed that they cleared through both hepatobiliary as well as renal route.…”

Radiolabeled Nanoparticles in Nuclear Oncology

“…Their in vivo biodistribution was assessed and high accumulation in the bladder and urine, and low intestinal uptake were demonstrated. Ex vivo biodistribution revealed accumulation in the RES organs which could be due to the negative surface charge of the nanoparticles, resulting in phagocytisis by macrophages of these organs [5]. A fast and simple strategy of radiolabeling and coating magnetic nanoparticles was introduced by Sun Z. et al (2016).…”

Positron Emission Tomography Image-Guided Drug Delivery: Current Status and Future Perspectives

“…126–129 The utilization of 18 F-labeled gold nanoparticles for PET imaging was first reported by Guerrero et al, 130 in which the gold nanoparticles of ~12 nm were synthesized by citrate reduction of HAuCl 4 . The nanoparticles were functionalized with two different peptides, CK and CLPFFD, and 18 F-SFB was covalently bound to the nano-particle conjugate.…”