Abstract 2381: Gold nanorods functionalized with an alpha5beta1 ligand: a simple and robust nanosystem for early bladder cancer detection
Authors: Alfano Massimo , Alchera Elisa , Sacchi Angelina , Gori Alessandro , Locatelli Irene , Gasparri Anna Maria , Colombo Barbara , Anderluzzi Giulia , Armanetti Paolo , Minichetti Luca , Salonia Andrea , Corti Angelo , Curnis Flavio 
Published: April 2023

Abstract
Early detection and removal of bladder cancer (BC) is crucial to prevent tumor recurrence and progression. Various imaging modalities have been used to diagnose BC, including computed tomography urography, intravenous urography, ultrasound echography, multiparametric magnetic resonance imaging, cystoscopy, and cystoscopy in conjunction with intravesical instillation of hexaminolaevulinic acid, a photodynamic diagnostic agent. However, all these imaging techniques show a very poor detection rate of small (&lt;5mm) and flattened cancer lesions. Because of this limitation, patients with BC frequently relapse after initial diagnosis and need frequent follow-ups and treatments, resulting in a poor quality of life. For the same reason, BC has the highest cost/patient among all cancers. We have recently developed a new methodology to detect bladder cancer lesions based on bladder instillation with GNRs@Chit-Iso4, a nanosystem consisting of gold nanorods (GNRs) decorated with chitosan and functionalized with the head-to-tail cyclized [CphgisoDGRG] peptide (Iso4, a selective ligand of alpha5beta1-integrin expressed by BC cells), followed by low-frequency ultrasound-assisted shaking of nanoparticles necessary to prevent their sedimentation, and photoacoustic imaging of targeted tumor lesions. In murine models, this procedure can detect orthotopic BC lesions &lt;0.5 mm, undetectable by standard imaging modalities (Alchera et al., Photoacoustic, 2022). In the attempt to develop a simpler and more effective imaging modality of BC, we have produced and preclinically evaluated new GNRs decorated with lipoic acid-polyethylene glycol (PEG -5KDa) and functionalized with Iso4. The resulting product, obtained by a simple 2-step procedure and called GNRs@PEG5K-Iso4, efficiently recognized alpha5beta1- and alpha5beta1-expressing cells, was stable in 90% urine, and was resistant to freezing- or salt-induced aggregation.GNRs@PEG5K-Iso4 did not undergo sedimentation after instillation into the bladder, thereby avoiding the need of the complex ultrasound-assisted shaking of nanoparticles and could efficiently detect BC lesions smaller than &lt;0.5 mm in murine models. These results suggest that GNRs@PEG5K-Iso4 represents a simple and robust contrast agent for photoacoustic imaging and early diagnosis of small BC lesions.
Citation Format: Massimo Alfano, Elisa Alchera, Angelina Sacchi, Alessandro Gori, Irene Locatelli, Anna Maria Gasparri, Barbara Colombo, Giulia Anderluzzi, Paolo Armanetti, Luca Minichetti, Andrea Salonia, Angelo Corti, Flavio Curnis. Gold nanorods functionalized with an alpha5beta1 ligand: a simple and robust nanosystem for early bladder cancer detection [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2381.