Improvement of doxorubicin radioiodination and in-vivo cancer suppression via loading in nanosilver system.

This study aimed at improving the radioiodination of doxorubicin (DOX) and its localization in cancer cell for theranostic purposes. To achieve this goal, a composite of DOX with polyvinyl pyrrolidone (PVP) and silver nanoparticles (AgNPs) was prepared. Both DOX and (DOX/PVP/AgNPs) were radiolabelled with iodine-125 [125I] and optimized using iodogen as a preferable oxidizing agent. The maximum obtained radiochemical yields for both systems were 79.9% and 96.6%, respectively. Interestingly, the biodistribution study revealed that [125I]DOX/PVP/AgNPs had an effective localization on tumors. Moreover, Target/control target (T/CT) ratio of [125I] DOX/PVP/AgNPs showed the highest value of 9.1 at 1 h post injection, suggesting that [125I]DOX/PVP/AgNPs has a great potential as a proposed tumor targeting agent.

Enhancing Tumor Targeting Efficiency of Radiolabeled Uridine (via) Incorporation into Nanocubosomal Dispersions.

Background: Several nanosystems are currently being utilized to enhance the targeting efficiency of several cancer chemotherapeutic agents. This study was designed to improve tumor accumulation of iodine-125 (125I)-uridine via incorporation into a nanocubosomal preparation. Materials and Methods: Nanocubosomes were prepared with the aid of Glycerol mono-oleate and Pluronic F127. Each prepared nanocubosomal preparation was adequately characterized by testing their particle size, polydispersity index (PDI), ζ potential (ZP), and transmission electron microscopy. The radiolabeling of uridine with 125I was attempted using several oxidizing agents to achieve a high radiochemical yield, and the factors affecting the reaction yield were studied in detail. A comparative biodistribution study of free 125I-uridine and 125I-uridine loaded nanocubosomes was performed in normal and tumor bearing mice. The biodistribution was evaluated by intravenous injection of the sterile test solution, and animals were anesthetized and dissected at different time intervals postinjection (p.i.). Results: 125I-uridine was obtained in a high radiochemical yield (92.5% ± 0.8%). Afterward, 125I uridine was incorporated in a selected nanocubosome formulation, which showed nanosized cubic particles (178.6 ± 0.90 nm) with PDI (0.301 ± 0.04) and a ZP (34.35 ± 0.4). The biodistribution studies revealed that 125I-uridine nanocubosomes showed higher tumor localization (3.1 ± 0.4%IA/g at 2 h p.i. and a tumor/muscle ratio of 6.2) compared with the free 125I-uridine (2.7% ± 0.4%IA/g at 2 h p.i. and a tumor/muscle ratio of 3.3). Conclusion: The results of this study confirmed that 125I-uridine loaded nanocubosome had better efficiency in targeting the tumor site, which makes it an adequate targeting agent for tumor imaging.

Preparation of 99mTc-levetiracetam intranasal microemulsion as the first radiotracer for SPECT imaging of the Synaptic Vesicle Protein SV2A.

Selective receptors imaging using gamma emitting radiopharmaceuticals allows accurate diagnosis and follow up of many brain related disorders. Levetiracetam, a selective SV2A receptor antiepileptic, was successfully radiolabeled using 99mTc. Different conditions affecting the labelling process were studied and optimum radiochemical yield of 89.8% was obtained. 99mTc-levetiracetam was effectively formulated and characterized as microemulsion with particle size of 16.34 ±â€¯5.58 nm and polydispersity index of 0.382 ±â€¯0.05. Parallel biodistribution studies were performed comparing brain targeting efficiency of I.V 99mTc-levetiracetam solution, I.N 99mTc-levetiracetam solution and I.N 99mTc-levetiracetam microemulsion. Brain radioactivity uptake and brain/blood uptake ratio for I.N 99mTc-levetiracetam microemulsion were higher than the other two routes at all time intervals. Such results present intranasal 99mTc-levetiracetam microemulsion as the first SPECT tracer for imaging SV2A receptor.

Comparative study on radiolabeling and biodistribution of core-shell silver/polymeric nanoparticles-based theranostics for tumor targeting.

A simple and rapid method for radiolabeling of three types of Ag NPs has been performed using 125I isotope, with high labeling yields, >90% without disturbing the optical properties. All the factors affecting labeling yield were studied. In order to monitor the in-vivo tissue uptake of radiolabeled Ag NPs using γ-rays, Ag-based radioiodo-NPs with a maximum labeling yield were intravenously injected in normal and solid tumor bearing mice. The preliminary biodistribution study revealed that this new radioiodo-NPs have a high affinity to be localized in the tumor site for a long period of time. The reported highly efficient method provides new radiolabeled Ag-based NPs as tumor-specific agents for both diagnostic and therapeutic applications.