Radiosynthesis and preclinical studies of 177Lu-labeled sulfadiazine: a possible theranostic agent for deep-seated bacterial infection

Dose-Dependent Internalization and Externalization Integrity Study of Newly Synthesized 99mTc-Thymoquinone Radiopharmaceutical as Cancer Theranostic Agent

Thymoquinone (TQ) is a bioactive phytochemical isolated from Nigella sativa and has been investigated for biochemical and biological activities in both in vitro and in vivo models. It is best known for its anticancer activities. Thymoquinone accomplishes anticancer activities through targeting multiple cancer markers including PPAR-γ, PTEN, P53, P73, STAT3, and generation of reactive oxygen species at the cancer cell surface. The radiolabeling of TQ with γ- and β-emitter radionuclide could be used as cancer diagnostic or therapeutic radiopharmaceutical, respectively. In this study, we are reporting the radiolabeling of TQ with technetium-99m (^99mTc), stability in saline and blood serum, internalization and externalization of ^99mTc-TQ using rhabdomyosarcoma cancer cells line. The quality control study revealed more than 95% labeling yield and stable in blood serum up to 4 hours. In vitro internalization rate was recorded 27.08% ± 0.95% at 1 hour post 2 hours internalization period and comparatively slow externalization. The results of this study are quite encourging and could be investigated for further key preclinical parameters to enter phase I clinical trials.

Emerging vistas in theranostic medicine

Recent years have witnessed a paradigm shift in the focus of healthcare towards development of customized therapies which cater to the unmet needs in a myriad of disease areas such as cancer, infections, cardiovascular diseases, neurodegenerative disorders and inflammatory disorders. The term 'theranostic' refers to such multifunctional systems which combine the features of diagnosis and treatment in a single platform for superior control of the disease. Theranostic systems enable detection of disease, treatment and real time monitoring of the diseased tissue. Theranostic nanocarriers endowed with multiple features of imaging, targeting, and providing on-demand delivery of therapeutic agents have been designed for enhancement of therapeutic outcomes. Fabrication of theranostics involves utilization of materials having distinct properties for imaging, targeting, and programming drug release spatially and temporally. Although the field of theranostics has been widely researched and explored so far for treatment of different types of cancer, there have been considerable efforts in the past few years to extend its scope to other areas such as infections, neurodegenerative disorders and cardiovascular diseases. This review showcases the potential applications of theranostics in disease areas other than cancer. It also highlights the cardinal issues which need to be addressed for successful clinical translation of these theranostic tools.

Technetium-99m radiolabeling and biological study of epirubicin for in vivo imaging of multi-drug-resistant Staphylococcus aureus infections via single photon emission computed tomography

The development of functional imaging is a promising strategy for diagnosis and treatment of infectious and cancerous diseases. In this study, epirubicin was developed as a [^99m Tc]-labeled radiopharmaceutical for the imaging of multi-drug-resistant Staphylococcus aureus infections. The labeling was carried out using sodium pertechnetate (Na^99m TcO₄ ; ~370 MBq). The other parameters such as amount of ligand, reducing agent (SnCl₂ .2H₂ O), and pH were optimized. The highest labeling yield ≥96.98% was achieved when 0.3 mg epirubicin, 13 μg SnCl₂ .2H₂ O, and ~370 MBq Na^99m TcO₄ were incubated at pH 7 for 15 min in the presence of ascorbic acid at room temperature. Radiochemical purity, stability, charge, and glomerular filtration rate were studied to evaluate the biological compatibility for in vivo administration. Biodistribution investigations showed radiotracer uptake (13.89 ± 1.56% ID/gm organ) by liver and 7.79 ± 0.38% ID/gm organ by kidneys at 30 min post-injection which promisingly wash out at 24 hr post-injection. Scintigraphy study showed selective uptake in S. aureus-infected tissues in contrast to turpentine oil-induced inflamed tissues. Target-to-non-target ratio (6.7 ± 0.05) was calculated at 1 hr post-injection using SPECT gamma camera. The results of this study reveal that the [^99m Tc]-epirubicin can be a choice of imaging and monitoring the treatment process of multi-drug resistant S. aureus bacterial infections.