Technetium-99m chelator-free radiolabeling of specific glutamine tumor imaging nanoprobe: in vitro and in vivo evaluations

Ligand-free 99mTc-polyurea dendrimer complexes: nanoradiotheranostics targeting ovarian cancer

A folic acid-targeted polyurea (PURE) dendrimer was easily radiolabelled with Technetium-99m (99mTc-PUREG4-FA2) avoiding the use of additional ligands and bioconjugation chemistry. This straightforward strategy is enabled in PURE dendrimers due to their favourable surface terminal groups configuration, showing coordination capabilities and turning these biodendrimers into attractive platforms for nanoradiotheranostics.

99mTc- Anionic dendrimer targeted vascular endothelial growth factor as a novel nano-radiotracer for in-vivo breast cancer imaging

Since breast cancer is the commonly cause of death among women around the world, diagnosis at the early stages is significantly important to prevent the metastasis of the cancer. Among the various growth factors that are involved in angiogenesis, vascular endothelial growth factor (VEGF) is believed to be the most important factor. Overexpressed VEGF receptor on tumors surface, is particularly interesting for cancer cells targeting purposes. In this study, citric acid dendrimer conjugated with VEGF antagonist peptide was synthesized. The obtained product was confirmed by FT-IR, TEM, DLS, and EDS. In vitro cytotoxicity assay showed no toxicity on normal cells and indicated the notably dose-dependence toxicity on cancer cells. Box-Behnken software as a computational method was used to determine the optimum amount of radiolabeling parameters. Optimized parameters for reducing agent, dendrimer-anti-VEGF, and time were 1.4 mg, 17.5 mg, and about 30 min respectively. Radiochemical purity of radio-labeled conjugated dendrimer was determined about 90 percent. SPECT imaging was done to observe the in vivo accumulation of dendrimer-anti-VEGF in the tumor site. Images showed high accumulation of radio-tracer in the tumor region. All in all, obtained results confirmed our hypothesis that the dendrimer-anti-VEGF can be a good radio-tracer for diagnosis of cancer.

Investigation for anticancer activity of the newly synthesized p-Methoxyphenyl maleanilic acid and the diagnostic property of its 99mTc-analogue

PURPOSE

The limitations of the current chemotherapeutics are the main rational to develop and/or explore new anticancer agents and radiolabeled analogues for cancer early diagnosis.

MATERIALS AND METHODS

The newly synthesized p-methoxyphenyl maleanilic acid (MPMA) was prepared, characterized and investigated for its anticancer activity. MPMA screened in-vitro against human hepatocellular carcinoma (HepG-2), human colon carcinoma (HCT-116) and human breast carcinoma (MCF-7) cell lines. Furthermore, the in-vivo screening was performed by radiolabeling of MPMA with technetium-99m (^99mTc) and investigating its biological distribution in normal mice and solid tumor models. Moreover, MPMA and its radiolabeled analogue were docked to Y220C and Y220S mutants of p53 (p53^Y220C and p53^Y220S) in an effort to confirm their affinity to cancer as well as to investigate, virtually, the mechanism of action of MPMA.

RESULTS

The results revealed significant potency of MPMA against HepG-2 cell line (IC₅₀ = 56.2 ± 1.5 µg/mL) if compared to HCT-116 (IC₅₀ = 89.9 ± 1.8 µg/mL) and MCF-7 (IC₅₀ = 104 ± 2.7 µg/mL) cell lines. The radiolabeling yield was optimized to be 90.2 ± 2.1%. The radiolabeled MPMA showed a good localization in the site of solid tumor (15.1 ± 1.6%ID/g) at 2 h post intravenous administration to the tumor bearing mice.

CONCLUSIONS

Collectively, the findings confirmed the potential anticancer activity of MPMA and the possible use of ^99mTc-MPMA for cancer diagnosis and monitoring.

Glutamine Imaging: A New Avenue for Glioma Management

The glutamine pathway is emerging as an important marker of cancer prognosis and a target for new treatments. In gliomas, the most common type of brain tumors, metabolic reprogramming leads to abnormal consumption of glutamine as an energy source, and increased glutamine concentrations are associated with treatment resistance and proliferation. A key challenge in the development of glutamine-based biomarkers and therapies is the limited number of in vivo tools to noninvasively assess local glutamine metabolism and monitor its changes. In this review, we describe the importance of glutamine metabolism in gliomas and review the current landscape of translational and emerging imaging techniques to measure glutamine in the brain. These techniques include MRS, PET, SPECT, and preclinical methods such as fluorescence and mass spectrometry imaging. Finally, we discuss the roadblocks that must be overcome before incorporating glutamine into a personalized approach for glioma management.

Biodistribution of Mesoporous Carbon Nanoparticles via Technetium-99m Radiolabelling after Oral Administration to Mice

The use of ordered mesoporous matrices, and in particular carbon-based mesoporous nanoparticles has shown great potential towards enhancing the bioavailability of orally administered drugs. Nevertheless, elucidation of the in vivo absorption, distribution, and excretion of such carriers is essential for understanding their behaviour, and radiolabelling provides a very useful way to track their occurrence inside the body. In this work, uniform spherical CMK-1-type ordered mesoporous carbon nanoparticles have been radiolabelled with Technetium-99m (99mTc) and traced after oral administration to mice. Ex vivo biodistribution studies showed that the radiolabelled nanoparticles accumulated almost exclusively in the gastrointestinal tract; complete elimination of the radiotracer was observed within 24 h after administration, with practically no uptake into other main organs. These findings along with the results from in vitro stability studies indicate that the spherical carbon nanoparticles examined could be safely used as drug carriers with minimal side effects, but also support the great value of radiolabelling methods for monitoring the particles' behaviour in vivo.

Recent Progress in Technetium-99m-Labeled Nanoparticles for Molecular Imaging and Cancer Therapy

Nanotechnology has played a tremendous role in molecular imaging and cancer therapy. Over the last decade, scientists have worked exceptionally to translate nanomedicine into clinical practice. However, although several nanoparticle-based drugs are now clinically available, there is still a vast difference between preclinical products and clinically approved drugs. An efficient translation of preclinical results to clinical settings requires several critical studies, including a detailed, highly sensitive, pharmacokinetics and biodistribution study, and selective and efficient drug delivery to the target organ or tissue. In this context, technetium-99m (^99mTc)-based radiolabeling of nanoparticles allows easy, economical, non-invasive, and whole-body in vivo tracking by the sensitive clinical imaging technique single-photon emission computed tomography (SPECT). Hence, a critical analysis of the radiolabeling strategies of potential drug delivery and therapeutic systems used to monitor results and therapeutic outcomes at the preclinical and clinical levels remains indispensable to provide maximum benefit to the patient. This review discusses up-to-date ^99mTc radiolabeling strategies of a variety of important inorganic and organic nanoparticles and their application to preclinical imaging studies.

Facile green synthesis of zero-valent iron nanoparticles using barberry leaf extract (GnZVI@BLE) for photocatalytic reduction of hexavalent chromium

In this study, zero-valent iron (GnZVI) was synthesized using barberry leaf extract (GnZVI@BLE). The physicochemical properties of the final products were characterized by FT-IR, SEM, TEM, and EDS techniques. The results of TEM analysis showed that the obtained iron zero-valent nanoparticles with a diameter between 20 and 40 nm and shell-core structures were successfully synthesized. The results of FT-IR confirmed the presence of various functional groups. The photocatalytic activity of synthesized nanoparticles was investigated by reduction of hexavalent chromium. Laboratory data showed that the presence of GnZVI@BLE as a nanocatalyst in the photocatalytic process could be reduction the hexavalent chromium (Cr (VI)). Photocatalytic data revealed that, when the dosage of nanoparticles was 0.675 g/L, the reduction efficiency of hexavalent chromium was 100%. The kinetics of the reaction follows a pseudo-second-order equation. The constant of reaction rate was 0.4 at pH 2 and 0.5 g/L concentration of GnZVI@BLE.

Radiolabelling of nanomaterials for medical imaging and therapy

Nanomaterials offer unique physical, chemical and biological properties of interest for medical imaging and therapy. Over the last two decades, there has been an increasing effort to translate nanomaterial-based medicinal products (so-called nanomedicines) into clinical practice and, although multiple nanoparticle-based formulations are clinically available, there is still a disparity between the number of pre-clinical products and those that reach clinical approval. To facilitate the efficient clinical translation of nanomedicinal-drugs, it is important to study their whole-body biodistribution and pharmacokinetics from the early stages of their development. Integrating this knowledge with that of their therapeutic profile and/or toxicity should provide a powerful combination to efficiently inform nanomedicine trials and allow early selection of the most promising candidates. In this context, radiolabelling nanomaterials allows whole-body and non-invasive in vivo tracking by the sensitive clinical imaging techniques positron emission tomography (PET), and single photon emission computed tomography (SPECT). Furthermore, certain radionuclides with specific nuclear emissions can elicit therapeutic effects by themselves, leading to radionuclide-based therapy. To ensure robust information during the development of nanomaterials for PET/SPECT imaging and/or radionuclide therapy, selection of the most appropriate radiolabelling method and knowledge of its limitations are critical. Different radiolabelling strategies are available depending on the type of material, the radionuclide and/or the final application. In this review we describe the different radiolabelling strategies currently available, with a critical vision over their advantages and disadvantages. The final aim is to review the most relevant and up-to-date knowledge available in this field, and support the efficient clinical translation of future nanomedicinal products for in vivo imaging and/or therapy.

Novel CoFe2O4@ZnO-CeO2 ternary nanocomposite: Sonochemical green synthesis using Crataegus microphylla extract, characterization and their application in catalytic and antibacterial activities

In this study, CoFe₂O₄@ZnO-CeO₂ magnetic nanocomposite (CoFe@Zn-Ce MNC) was successfully prepared by facile sonochemical method for the first time. CoFe@Zn-Ce MNC was obtained by green and cost-effective process in the presence of Crataegus microphylla (C. microphylla) fruit extract. Influence of some parameters like capping agents (C. microphylla, SDS and CTAB), sonication time (10, 30 and 60 min) and sonication power (40, 60 and 80 W) were studied to achieve optimum condition. The as-obtained products were characterized by FT-IR, FESEM, TEM, DRS, VSM, EDS, TGA and XRD analysis. Results showed that high magnetic properties (20.38 emug^-1), 70-80 nm size and spherical morphology were unique characteristics of synthesized nanocomposite. Antibacterial activity of CoFe@Zn-Ce MNC was examined against E. coli, P. aeruginoss and S. aureus bacteria. Among theme, S. aureus as gram-positive bacteria showed excellent antibacterial activity. Furthermore, photocatalytic performance of the CoFe@Zn-Ce MNC was investigated by degradation of humic acid (HA) molecules under visible and UV light irradiations. The influence of morphology of products and incorporation of cerium oxide with CoFe₂O₄@ZnO on photocatalytic activity of CoFe₂O₄@ZnO was performed. After 100 min illumination, the decomposition of HA pollutant by magnetic nanocomposite were 97.2% and 72.4% under exposure of UV and visible light irradiations, respectively. Also, CoFe@Zn-Ce MNC demonstrated high stability in the cycling decomposition experiment after six times cycling runs.

Synthesis, radiolabelling, and biological assessment of folic acid-conjugated G-3 99mTc-dendrimer as the breast cancer molecular imaging agent

Hence, in this study, the authors aimed to develop a dendrimer-based imaging agent comprised of poly(ethylene glycol) (PEG)-citrate, technetium-99 m (99mTc), and folic acid. The dendrimer-G3 was synthesised and conjugated with folic acid, which confirmed by Fourier transform infrared, proton nuclear magnetic resonance, dynamic light scattering, and transition electron microscopy. 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-Tetrazolium-5-Carboxanilide cytotoxicity assay kit was used to measure the cellular toxicity of dendrimer. Imaging and biodistribution studies were conducted on the mice bearing tumour. The results showed that the fabricated dendrimer-G3 has a size of 90 ± 3 nm, which was increased to 100 ± 4 nm following the conjugation with folic acid. The radiostablity investigation showed that the fabricated dendrimers were stable in the human serum at various times. Toxicity assessment confirmed no cellular toxicity against HEK-293 cells at 0.25, 0.5, 1, 2, 4, and 8 mg/μl concentrations. The in vivo studies demonstrated that the synthesised dendrimers were able to provide a bright SPECT image applicable for tumour detection. In conclusion, the authors' study documented the positive aspects of PEG-citrate dendrimer conjugated with folic acid as the SPECT contrast agent for breast cancer detection.

99mTc-citrate-gold nanoparticles as a tumor tracer: synthesis, characterization, radiolabeling and in-vivo studies

Targeted drug delivery system can reduce the side effects of high drug concentration by improving drug pharmacokinetics at lower doses. Citrate-gold nanoparticles (AuNPs) as a drug delivery system were synthesized via green nanotechnology technique to be used as a new imaging platform for tumor targeting. Citrate-AuNPs were synthesized with core size of 10 nm. Citrate-AuNPs were labeled with technetium-99m (99mTc) with radiochemical yield of 95.20 ± 2.70% with good in-vitro stability in both saline and human serum and well in-vivo studied in both normal and solid tumor bearing mice. The in-vivo biodistribution study of [99mTc]Tc-citrate-AuNPs in solid tumor bearing mice (as preliminary study) showed a high accumulation in tumor site with tumor/muscle of 4.35 ± 0.22 after 30 min post injection. The direct intratumoral (I.T) injection of [99mTc]Tc-citrate-AuNPs showed that this complex was retained in the tumor up to 77.86 ± 1.90 % at 5 min and still around 50.00 ± 1.42 % after 30 min post injection (p.i.). The newly presented nano-platform could be presented as a new potential radiopharmaceutical tumor imaging probe.

Trends in Nanotechnology for in vivo Cancer Diagnosis: Products and Patents

BACKGROUND

Cancer is a set of diseases formed by abnormal growth of cells leading to the formation of the tumor. The diagnosis can be made through symptoms' evaluation or imaging tests, however, the techniques are limited and the tumor detection may be late. Thus, pharmaceutical nanotechnology has emerged to optimize the cancer diagnosis through nanostructured contrast agent's development.

OBJECTIVE

This review aims to identify commercialized nanomedicines and patents for cancer diagnosis.

METHODS

The databases used for scientific articles research were Pubmed, Science Direct, Scielo and Lilacs. Research on companies' websites and articles for the recognition of commercial nanomedicines was performed. The Derwent tool was applied for patent research.

RESULTS

This article aimed to research on nanosystems based on nanoparticles, dendrimers, liposomes, composites and quantum dots, associated to imaging techniques. Commercialized products based on metal and composite nanoparticles, associated with magnetic resonance and computed tomography, have been observed. The research conducted through Derwent tool displayed a small number of patents using nanotechnology for cancer diagnosis. Among these patents, the most significant number was related to the use of systems based on metal nanoparticles, composites and quantum dots.

CONCLUSION

Although few systems are found in the market and patented, nanotechnology appears as a promising field for the development of new nanosystems in order to optimize and accelerate the cancer diagnosis.

PEG-Citrate dendrimer second generation: is this a good carrier for imaging agents In Vitro and In Vivo?

While cancer is the leading cause of human's deaths worldwide, finding an imaging agent which can detect cancer tumours is needed for cancer diagnosis. In the present study, PEG-citrate dendrimer-G2 was used as a nano-carrier of FITC dye and Iohexol to help passive targeting and uptake of both imaging agents in cancer cells/tumour in vitro and in vivo. Dendrimer was synthesisedand the product characterised using LC-MS, FT-IR, DLS, ELS, AFM, and 1HNMR. After FITC loading into dendrimer, MTT was performed to determine the cytotoxicity of formulation on HEK-293 and MCF-7 cells. In vitro imaging using dendrimer-FITC was done via fluorescent microscope thereafter. Moreover, CT imaging using Iohexol was employed to show the targeting nature and ability of the complex to use as imaging agent in vivo. Data yielded in this study corroborate the notion that the promised dendrimer was synthesised properly and had no toxicity along with FITC on normal cell. Furthermore, CT and fluorescent images showed the targeting nature and imaging ability of Iohexol/FITC loaded dendrimer in vitro and in vivo. Overall, results showed promising characteristics of the novel complexes using dendrimer-G2 both in vitro and in vivo.

Novel nanosized AS1411-chitosan-BODIPY conjugate for molecular fluorescent imaging

Background: In recent years, non-invasive imaging technologies for early cancer detection have drawn worldwide attention. In this study, an antinucleolin aptamer, AS1411, was successfully conjugated to BODIPY-labeled chitosan and studied on T47D and HEK-293 cell lines. Methods: After conjugation of the aptamer to chitosan nanoparticles and purification, its structure was confirmed using atomic force microscopy (AFM), electrophoretic light scattering (ELS) and dynamic light scattering (DLS). Results of AFM, DLS and ELS of both conjugation and chitosan were compared for confirmation of conjugation. Conjugates were mixed with BODIPY FL fluorescent dye, purified and lyophilized. The labeled conjugate was characterized using Fourier-transform infrared spectroscopy, ultraviolet-visible spectroscopy, ELS and DLS. In vitro cellular uptake and cytotoxic effects of BODIPY-labeled chitosan-AS1411 aptamer conjugates were evaluated using the XTT assay on T47D and HEK-293 cells and flow cytometry on T47D cells. Results: The data showed that uptake of BODIPY-labeled chitosan-AS1411 aptamer conjugate was satisfactory. Moreover, there was no statistically significant cytotoxicity of the conjugate on either cell line. Conclusion: The outcomes confirmed the potential application of this new targeted imaging agent as a novel cancer diagnostic agent for molecular imaging.