Preliminary studies of 68Ga-NODA-USPION-BBN as a dual-modality contrast agent for use in positron emission tomography/magnetic resonance imaging

Advancements in nanotechnology for diagnostics: a literature review, part II: advanced techniques in nuclear and optical imaging

Modern molecular imaging routes, such as nuclear imaging and optical imaging, derive significant advantages from nanoparticles, where multimodality use and multipurpose are key benefits. Nanoparticles also showcase benefits over traditional imaging agents in nuclear and optical imaging, including improved resolution, penetration, and specificity. The goal of this literature review was to explore recent advancements in nanomaterials within these molecular imaging techniques to expand on the current state of nanomedicine in these modalities. This review derives findings from relevant reviews, original research papers, in-human clinical trials, and patents in the literature. Au- and Fe oxide-based nanosystems are just as ubiquitous within more modern modalities due to their multimodal diagnostic and therapeutic potential. It is also repeatedly highlighted in the literature, patents, and clinical trials that the use of nanoparticles, specifically in multimodal imaging techniques and theranostics, present innovative methods in recent years, enabling researchers and clinicians to overcome the limitations of unimodal imaging modalities and further advancing accuracy in the diagnosis and treatment of important pathologies, particularly cancer. Overall, nanoparticle-based imaging represents a transformative approach in advanced imaging modalities, offering new approaches to limitations of conventional agents currently being applied in clinical settings.

Nanostrategies for Therapeutic and Diagnostic Targeting of Gastrin-Releasing Peptide Receptor

Advances in nanomedicine bring the attention of researchers to the molecular targets that can play a major role in the development of novel therapeutic and diagnostic modalities for cancer management. The choice of a proper molecular target can decide the efficacy of the treatment and endorse the personalized medicine approach. Gastrin-releasing peptide receptor (GRPR) is a G-protein-coupled membrane receptor, well known to be overexpressed in numerous malignancies including pancreatic, prostate, breast, lung, colon, cervical, and gastrointestinal cancers. Therefore, many research groups express a deep interest in targeting GRPR with their nanoformulations. A broad spectrum of the GRPR ligands has been described in the literature, which allows tuning of the properties of the final formulation, particularly in the field of the ligand affinity to the receptor and internalization possibilities. Hereby, the recent advances in the field of applications of various nanoplatforms that are able to reach the GRPR-expressing cells are reviewed.

Methods for Radiolabelling Nanoparticles: PET Use (Part 2)

The use of radiolabelled nanoparticles (NPs) is a promising nuclear medicine tool for diagnostic and therapeutic purposes. Thanks to the heterogeneity of their material (organic or inorganic) and their unique physical and chemical characteristics, they are highly versatile for their use in several medical applications. In particular, they have shown interesting results as radiolabelled probes for positron emission tomography (PET) imaging. The high variability of NP types and the possibility to use several isotopes in the radiolabelling process implies different radiolabelling methods that have been applied over the previous years. In this review, we compare and summarize the different methods for NP radiolabelling with the most frequently used PET isotopes.

Advances in Development of Radiometal Labeled Amino Acid-Based Compounds for Cancer Imaging and Diagnostics

Radiolabeled biomolecules targeted at tumor-specific enzymes, receptors, and transporters in cancer cells represent an intensively investigated and promising class of molecular tools for the cancer diagnosis and therapy. High specificity of such biomolecules is a prerequisite for the treatment with a lower burden to normal cells and for the effective and targeted imaging and diagnosis. Undoubtedly, early detection is a key factor in efficient dealing with many severe tumor types. This review provides an overview and critical evaluation of novel approaches in the designing of target-specific probes labeled with metal radionuclides for the diagnosis of most common death-causing cancers, published mainly within the last three years. Advances are discussed such traditional peptide radiolabeling approaches, and click and nanoparticle chemistry. The progress of radiolabeled peptide based ligands as potential radiopharmaceuticals is illustrated via novel structure and application studies, showing how the molecular modifications reflect their binding selectivity to significant onco-receptors, toxicity, and, by that, practical utilization. The most impressive outputs in categories of newly developed structures, as well as imaging and diagnosis approaches, and the most intensively studied oncological diseases in this context, are emphasized in order to show future perspectives of radiometal labeled amino acid-based compounds in nuclear medicine.

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.

Implications of Biomolecular Corona for Molecular Imaging

The development of nanoparticle probes has opened up new possibilities for molecular imaging in the era of precision medicine. There are a wide range of nanoprobes that are being used for various modalities that have demonstrated promising potential in early detection, disease monitoring, and theranostics. However, the rate of successful clinical translation of the nanoprobes is very low and is affected by the lack of our understanding about nanoparticle interaction with biological fluids after systemic administration, thus representing an unmet clinical need. One of the poorly understood issues relates to the formation of biomolecular corona, a layer of biomolecules formed on the surface of nanoscale materials during their interactions with biological fluids. The biomolecular corona has several significant effects on the biodistribution of nanoprobes and their imaging ability by (i) reducing their targeting efficacy and (ii) affecting the intrinsic imaging properties (e.g., contrast capacity of magnetic nanoprobes). This review provides insights on the importance of considering biomolecular corona in the development of nanoprobes, which may enable their more efficient utilization for molecular imaging applications.

Development of Ga-68 labeled, biotinylated thiosemicarbazone dextran-coated iron oxide nanoparticles as multimodal PET/MRI probe

Bifunctional biotinylated thiosemicarbazone dextran-coated iron oxide Nanoparticles (NPs) were fabricated. Aldehyde groups of the oxidized dextran-coating layer were utilized to conjugate biotin as a tumor-targeting agent and thiosemicarbazide as a cation chelator on the surface of NPs. The final product was characterized for physicochemical and biological properties. It was compatible with red blood cells and did not change the blood coagulation time. It also showed a significantly enhanced affinity to biotin receptor-positive 4T1 cells compared to non-biotinylated ones. The r2 relaxivity coefficient value of the final product was 110.2 mM^-1 s^-1. Although biotinylated NPs were easily radiolabeled with Ga-68 at room temperature, the stable radiolabeled NPs were achieved at a higher temperature (60 °C). The radiolabeled NPs were majorly accumulated in the liver and spleen. However, about 5.4% ID/g of the radiolabeled NPs was accumulated within the 4T1 tumor site. Blocking studies was performed by the biotin molecules pre-injection showed uptake reduction in the 4T1 tumor (about 1.1% ID/g). The radiolabeled NPs could be used for the early detection of biotin receptor-positive tumors via PET-MRI.