Prostate cancer targeted kit design; development of platinum and titanium nanoparticle based conjugates, radioisotopic modifications and in vitro/in vivo applications

Prostate cancer is a common disease in men and the leading cause of cancer death. Risk factors; age, ethnicity, family, genetics and other environmental factors. Rectal examination, Trans-Rectal ultrasound and Prostate Specific Antigen (PSA) test are used to diagnosis of prostate cancer. Surgery (radical prostatectomy), external radiotherapy, brachytherapy, high intensity focused ultrasound (HIFU), cryotherapy, chemotherapy and hormone therapy are used in the treatment of prostate cancer. However, with the widespread use of nanoscience in healthcare as in many other areas, its importance for cancer research is increasing. Nanoparticles, in particular the noble metal, have significant advantages due to their optical and electronic effects. Platinum nanoparticles are highly suitable for diagnosis and treatment due to their intrinsic catalytic properties and optical properties. Titanium nanoparticles are considered as ideal semiconductors for photocatalysis due to their high stability, low cost and environmental reliability. Especially when used as a composite, it has been found that they have a stronger effect than they are alone, by creating a synergistic effect. However, it has been found that SPHINX compound causes anti-angiogenesis by producing VEGFA165a member of the family of vascular endothelial growth factor A (VEGF-A), which plays a key role as angiogenic factor in the formation of new blood vessels (angiogenesis). Therefore, a multimodal nanoconjugate was designed with conjugation of these three components which have different effects. For characterization, size and morphology were determined using HPLC, DLS, TEM. Nanoconjugate was radiolabeled with 131/125I for gamma cameras and radiolabeled with 89Zr for PET imaging. The quality control of radiolabeling was performed HPLC and TLRC then stability and lipophilicity studies were done. Cell studies were started with PC3, LNCaP and RWPE-1 cells. Cytotoxicity, cell uptake, photodynamic therapy / radiotherapy simulation and ELISA studies were performed. PC3 and LNCaP xenograft models were developed with immunocompromised animals and PET imaging were performed with 89Zr radiolabeled nanoconjugate by injecting to mice according to the data obtained from cell studies. As a result of these studies, synthesized Pt-TiO2-Spx nanoconjugate has been reduced the viability of PC3 and LNCaP cells. While nanoconjugate shows toxicity in prostate cancer cells, it does not affect normal cells, it can be explained by the information that Spx works on the mechanism of SRPK inhibition in cancer cells. This result was also visually supported by AFM images. The nanoconjugate has been made selective to cancer cells because of this mechanism belongs to cancer cells. The cell uptake results are also in parallel with the cytotoxicity results; 131/125I and 89Zr radiolabelled nanoconjugate was being highly uptaken by PC3 and LNCaP cells, although there was no affinity to RWPE-1 cells. According to the results of photodynamic therapy / radiotherapy simulation; nanoconjugate increased radiation damage in prostate cancer cells when excitated with light and increased cell death as a result of increased damage. The viability of RWPE-1 cells, was higher than prostate cancer cells. This is very important in terms of target / non-target tissue ratio in possible in vivo use of the nanoconjugate. According to the ELISA results, after the incubation with nanoconjugate, the ratio of VEGF165b, which is the anti-angiogenic form of VEGF165 in the cell medium containing the metabolic wastes of the cells, increased and this situation maintained the characteristic of anti-angiogenesis after conjugation. As a result of animal studies, it was observed that 89Zr-Pt-TiO2-Spx had more effect on PC3 xenograft tumor model compared to LNCaP and no uptaken was observed in vital organs. The obtained in vitro and in vivo data demonstrated that the 131/125I and 89Zr radiolabeled Pt-TiO2-Spx nanoconjugate has a strong potential for multimodal diagnosis and treatment of prostate cancer, particularly in terms of target / non-target tissue ratio. Keywords: Platinum, titanium dioxide, SPHINX, prostate cancer, 131/125Iodine, 89Zirconium, Fotodynamic therapy/Raiyotherapy, Xenograft tumor model.