Radiolabeled iron oxide nanoparticles functionalized with PSMA/BN ligands for dual-targeting of prostate cancer

IntroductionProstate cancer (PCa) is the second most frequent cancer diagnosis in men and the fifth leading cause of death worldwide. Prostate Specific Membrane Antigen (PSMA) and Gastrin Releasing Peptide (GRP) receptors are overexpressed in PCa. In this study, we have developed iron oxide nanoparticles (IONs) functionalized with the Prostate Specific Membrane Antigen (PSMA) and Gastrin Releasing Peptide (GRP) ligands for dual targeting of Prostate cancer.MethodsIONs were developed with a thin silica layer on their surface with MPTES (carrying -SH groups, IONs-SH), and they were coupled either with a pharmacophore targeting PSMA (IONs-PSMA) or with bombesin peptide (IONs-BN), targeting GRP receptors, or with both (IONs-PSMA/BN). The functionalized IONs were characterized for their size, zeta potential, and efficiency of functionalization using dynamic light scattering (DLS) and Fourier-Transform Infrared Spectroscopy (FT-IR). All the aforementioned types of IONs were radiolabeled directly with Technetium-99m (99mTc) and evaluated for their radiolabeling efficiency, stability, and binding ability on two different PCa cell lines (PC3 and LNCaP).Results and DiscussionThe MTT assay demonstrated low toxicity of the IONs against PC3 and LNCaP cells, while the performed wound-healing assay further proved that these nanostructures did not affect cellular growth mechanisms. The observed hemolysis ratio after co-incubation with red blood cells was extremely low. Furthermore, the 99mTc-radiolabeled IONs showed good stability in human serum, DTPA, and histidine, and high specific binding rates in cancer cells, supporting their future utilization as potential diagnostic tools for PCa with Single Photon Emission Computed Tomography (SPECT) imaging

Radiolabeled iron oxide nanoparticles functionalized with PSMA/GRPR ligands for dual-targeting of prostate cancer

Ο καρκίνος του προστάτη είναι η δεύτερη πιο συχνή διάγνωση καρκίνου στους άνδρες και η πέμπτη κύρια αιτία θανάτου παγκοσμίως. Σε αυτή τη μελέτη, ετοιμάσαμε σιδηρομαγνητικά νανοσωματίδια (IONPs) για διπλή στόχευση, τροποποιημένα με υποδοχείς PSMA/GRPR, τα οποία μετά από ραδιοεπισήμανση με 99mTc και 68Ga, θα μπορέσουν να χρησιμοποιηθούν ως πιθανά διαγνωστικά εργαλεία για τον καρκίνο του προστάτη με απεικόνιση SPECT ή PET. Οι δύο δραστικές ουσίες, glu-urea-lys και bombesin (RM2), που στοχεύουν τα ετεροδιμερή PSMA και GRPR, συζεύχθηκαν με IONPs που φέρουν ομάδες -SH και χαρακτηρίστηκαν για το μέγεθος, το ζ-δυναμικό, τη δομή και την αποτελεσματικότητά τους με τη χρήση DLS, FT-IR και RP-HPLC. Τα τροποποιημένα IONPs ραδιοεπισημάνθηκαν απευθείας και αξιολογήθηκαν για την αποτελεσματικότητα, τη σταθερότητα και την ικανότητα δέσμευσης. Αυτά τα νανοσωματίδια παρουσίασαν χαμηλή τοξικότητα στα καρκινικά κύτταρα του προστάτη (PC3, LNCaP) και το ποσοστό της αιμόλυσης των ερυθρών αιμοσφαιρίων ήταν εξαιρετικά χαμηλή έως και μηδενική. Επιπλέον, ήταν σταθερά στον ανθρώπινο ορό, το DTPA και την ιστιδίνη και τα ποσοστά εσωτερικοποίησης ήταν υψηλότερα όσον αφορά τα καρκινικά κύτταρα PC3. Αυτή η μελέτη δείχνει ότι ετεροδιμερείς ενώσεις που στοχεύουν ταυτόχρονα και τους υποδοχείς PSMA και GRPR, όπως τα νανοσωματίδια που παρουσιάζονται σε αυτή τη διατριβή, μπορούν να ενισχύσουν σημαντικά την απεικόνιση του καρκίνου του προστάτη, έχοντας έτσι μια αξιοσημείωτη καινοτομία στην ανίχνευση του πρωτοπαθούς καρκίνου του προστάτη στα πρώιμα στάδια ανάπτυξής του.Prostate cancer is the second most frequent cancer diagnosis in men and the fifth leading cause of death worldwide. In this study, we have prepared dual-targeting iron oxide nanoparticles (IONPs) having high affinity and specificity for PSMA/GRP receptors, which after radiolabeling with 99mTc and 68Ga, could be utilized to serve as potential diagnostic tools for prostate cancer with SPECT or PET imaging. The two pharmacophores, glu-urea-lys and bombesin (RM2), targeting the bispecific heterodimers PSMA and GRPR, were coupled to IONPs carrying -SH groups and were characterized for their size, zeta potential, structure, and efficiency of functionalization using dynamic light scattering (DLS), FT-IR and RP-HPLC. The functionalized IONPs were radiolabeled directly and evaluated for their radiolabeling efficiency, stability, and binding ability. These nanoparticles presented low toxicity in prostate cancer cells (PC3, LNCaP) and the haemolysis ratio of red blood cells was extremely low. Furthermore, their radiolabeled counterparts were stable in human serum, DTPA, and histidine, and the internalization rates were higher regarding PC3 cancer cells. This study indicates that bispecific heterodimeric compounds that simultaneously target both PSMA and GRP receptors such as the nanoparticles presented in this thesis, may considerably enhance prostate cancer imaging, thus having a remarkable value in detecting primary prostate cancer in its early stages of development

Table1_Radiolabeled iron oxide nanoparticles functionalized with PSMA/BN ligands for dual-targeting of prostate cancer.docx

IntroductionProstate cancer (PCa) is the second most frequent cancer diagnosis in men and the fifth leading cause of death worldwide. Prostate Specific Membrane Antigen (PSMA) and Gastrin Releasing Peptide (GRP) receptors are overexpressed in PCa. In this study, we have developed iron oxide nanoparticles (IONs) functionalized with the Prostate Specific Membrane Antigen (PSMA) and Gastrin Releasing Peptide (GRP) ligands for dual targeting of Prostate cancer.MethodsIONs were developed with a thin silica layer on their surface with MPTES (carrying -SH groups, IONs-SH), and they were coupled either with a pharmacophore targeting PSMA (IONs-PSMA) or with bombesin peptide (IONs-BN), targeting GRP receptors, or with both (IONs-PSMA/BN). The functionalized IONs were characterized for their size, zeta potential, and efficiency of functionalization using dynamic light scattering (DLS) and Fourier-Transform Infrared Spectroscopy (FT-IR). All the aforementioned types of IONs were radiolabeled directly with Technetium-99m (99mTc) and evaluated for their radiolabeling efficiency, stability, and binding ability on two different PCa cell lines (PC3 and LNCaP).Results and DiscussionThe MTT assay demonstrated low toxicity of the IONs against PC3 and LNCaP cells, while the performed wound-healing assay further proved that these nanostructures did not affect cellular growth mechanisms. The observed hemolysis ratio after co-incubation with red blood cells was extremely low. Furthermore, the 99mTc-radiolabeled IONs showed good stability in human serum, DTPA, and histidine, and high specific binding rates in cancer cells, supporting their future utilization as potential diagnostic tools for PCa with Single Photon Emission Computed Tomography (SPECT) imaging.</p