Developing Peptide based Nanoconstructs as Potential Theranostic Agents

R. ZAHOOR; A. SHAHID; A. R. JALILIAN; R. ZAHOOR; A. SHAHID; A. R. JALILIAN; I. U. KHAN; A. FATIMA; C. Y. FLORES; I. U. KHAN; A. FATIMA; C. Y. FLORES; E. ACHILLI; M. SOHAIB; M. GRASSELLI; E. ACHILLI; M. SOHAIB; M. GRASSELLI

Barcelona

Congreso; Annual Congress of the European Association of Nuclear Medicine; 2019

European Association of Nuclear Medicine

The acronym THERANOSTICS epitomizesthe inseparability of diagnosis and therapy, the pillars ofmedicine and takes into account personalized managementof disease (usually based on nanomedicine) for a specificpatient. Nanomedicines, especially in round shape particles ornanoparticles (NPs), are studied for application in the field ofdiagnosis and treatment of cancer. In this research work, wereport on developing novel hybrid NPs (HNPs) prepared witha gold core and a multilayer coating of albumin (Alb) stabilisedby a novel radiation-induced crosslinking method. The resultantbioconjugate thus possesses characteristics that make it highlybiocompatible and a multifunctional platform for covalentimmobilization of peptides. Materials and Methods: HNPswere decorated with a DOTA-Bombesin synthetic peptide inorder to address cancer cells which overexpress GRP receptors.For fluorescence detection experiments, NPs were labeledwith NHS ester BODIPY 630/650. Confocal microscope pictureswere captured with Olympus FV300/BX61 microscope. FlowCytometry analyses were performed with a BD FACSCalibur®cytometer. Briefly, cells were incubated for 1, 2 or 4 h withNPs diluted in the complete medium. Data acquisition andanalyses were performed using the BD CellQuest Pro softwarepackage, recording 20,000 events. Radiolabeling was done with177Lu/68Ga and tested the biological compatibility of novel radiobioconjugatein rabbit animal models. Results: The conjugationof novel albumin-gold NPs with DOTA-BBN was characterizedby the plamon peak and absorbance at 280 nm. The increment of absorbance at 280 nm shows the conjugation of peptidewith albumin-gold nanoparticles. Flow cytometry analysis andconfocal microscopy were applied to study the in-vitro specificinteraction of these nanoconstructs to PC-3 and NCI-H460 celllines. Furthermore, we tested the cytotoxicity of novel nanoconstructs by using 3T3 and Hela cells. The binding affinity ofthe decorated HNPs to gastrin-releasing peptide (GRP) receptorwas tested by using PC-3; which was found in nanomolarrange. The radiolabeling yield in most cases was >90%. Theclinical potential of these radiolabeled nano bioconstructswas ultimately evaluated in tumor-bearing mice that showedsiginificant uptake in tumor xenografts. Conclusion: Novelradiolabeled nanoconstructs based on gold NPs stabilized withmany Alb layers may have great potential to be further evaluatedas feasible tumor-seeking agents. This approach might befurther extended to a tumor-specific targeting by using variousneuropeptide derivatives as carrier of chemotherapeuticagents and should be tested in various malignancies beyondprostate cancer, thus ultimately, used as a future tool forPeptide Receptor Radionuclide Therapy. References:None.