Preparation and biological evaluation of radio conjugated cephradine complex for infection imaging.

Antimicrobial resistance is a major challenge in the field and threat to human life. Many patients are suffering from cancer, infection and other diseases simultaneously. Therefore, early detection of infection can lead to treatment of these patients with an appropriate antibiotic. Hence, the development of a specific imaging molecule can increase the speed of infection analysis and thereby application of proper antibiotic. The present work involves the optimization of labelling conditions for an antibiotic of cephalosporin family, cephradine with technetium-99m (99mTc) and establishment of quality control tests. Labelling of cephradine was also determined by applying MALDI-TOF mass spectrometry. Evaluation of in vitro binding with S. aureus bacteria was carried out. Animal model was used to conduct in vivo binding studies. For this, infected animals were injected with the radiolabelled ligand and images were captured by Gamma camera, to observe target to non-target uptake of radiolabelled complex. Furthermore, we optimized various parameters to achieve best labelling efficacy and stability of cephradine. Our results show that cephradine can be used as potential infection imaging agent for advanced clinical care.

Microwave assisted synthesis of Fe3O4 stabilized ZrO2 nanoparticles - Free radical scavenging, radiolabeling and biodistribution in rabbits.

AIMS: In vivo biodistribution of radio labeled ZrO2 nanoparticles is addressed for better imaging, therapy and diagnosis. Nanoparticles are synthesized by microwave assisted sol-gel technique using Fe3O4 as a stabilizer. Antioxidant assay, hemolytic activity in human blood and biodistribution in rabbits was explored to study the therapeutical as well as in vivo targeted diagnostic applications of as synthesized nanoparticles. MAIN METHODS: Fe3O4 stabilized zirconia nanoparticles are synthesized using microwave assisted sol-gel method. Microwave (MW) powers are varied in the range of 100 to 1000 W. As synthesized nanoparticles are evaluated using different characterizations such as X-ray diffractometer, scanning electron microscope, Raman spectroscopy, impedance analyzer, Vickers micro hardness indenter, FTIR, and UV-Vis spectroscopy. In vitro activity of synthesized nanoparticles is checked in freshly extracted human blood serum. To study biodistribution of Fe3O4 stabilized zirconia nanoparticles in rabbit, technetium-99 m was used for labeling purpose. The labeling efficacy and stability of labeled nanoparticles are also measured with instant thin layer chromatography (ITLC) method. Intravenous injection of 99mTc-Fe3O4 stabilized zirconia nanoparticles (0.2 ml), containing 110 MBq of radioactivity, is performed to study the biodistribution; nanoparticles are injected into the ear vein of animal (rabbit). KEY FINDINGS: Zirconia (ZrO2) nanoparticles (NPs) are stabilized using Fe3O4 that were prepared by means of microwave assisted sol-gel method. Crystallite size (~20 nm) agrees well with the values required to stabilize tetragonal zirconia (t-ZrO2). Volume shrinkage results in high value of hardness (~1369). Dielectric constant values, compatible for biomedical application, are observed for tetragonally stabilized samples. Low value of hemolytic response is observed for Fe3O4 stabilized ZrO2 NPs. 99mTc radio labeled ZrO2 NPs proved to be potential candidate to study biodistribution. Biodistribution studies show stability of radiolabeled NPs in the original suspension as well as in blood serum. CT scan of rabbit is performed for several times to check the biodistribution of NPs with time and survival of rabbit. Results suggest that these NPs can also be used as targeted nanoparticles as well as variants of drug payload carrier. SIGNIFICANCE: Results signify that Fe3O4 stabilized ZrO2 nanoparticles synthesized by microwave assisted sol-gel method may be considered as "all-rounder" nanoplatform and are safe enough to be used in diagnostic as well as therapeutic purposes.