Current Radiopharmaceuticals

Calcium Carbonate Microparticles as Carriers of 224 Ra: Impact of Specific Activity in Mice with Intraperitoneal Ovarian Cancer

Background: Patients with advanced-stage ovarian cancer face a poor prognosis because of recurrent peritoneal cavity metastases following surgery and chemotherapy. Alpha-emitters may enable the efficient treatment of such disseminated diseases because of their short range and highly energetic radiation. Radium-224 is a candidate α-emitter due to its convenient 3.6-day half-life, with more than 90% of the decay energy originating from α-particles. However, its inherent skeletal accumulation must be overcome to facilitate intraperitoneal delivery of the radiation dose. Therefore, 224Ra-labeled CaCO3microparticles have been developed. Objective: The antitumor effect of CaCO3microparticles as a carrier for 224Ra was investigated, with an emphasis on the ratio of activity to mass dose of CaCO3, that is, specific activity. Methods: Nude athymic mice were inoculated intraperitoneally with human ovarian cancer cells (ES-2) and treated with a single intraperitoneal injection of 224Ra-labeled CaCO3microparticles with varying combinations of mass and activity dose, or cationic 224Ra in solution. Survival and ascites volume at sacrifice were evaluated. Results: Significant therapeutic effect was achieved for all tested specific activities ranging from 0.4 to 4.6 kBq/mg. Although treatment with a mean activity dose of 1305 kBq/kg of cationic 224Ra prolonged the survival compared with the control, equivalent median survival could be achieved with 224Ra-labeled microparticles with a mean dose of only 420 kBq/kg. The best outcome was achieved with the highest specific activities (2.6 and 4.6 kBq/mg). Conclusion: Radium-224-labeled CaCO3microparticles present a promising therapy against cancer dissemination in body cavities.

In Situ Photo Responsive Biodegradable Nanoparticle Forming Intrauterine Implant for Drug Delivery to Treat Ovarian Diseases: A Rationale-based Review

: Ovarian disease constitutes various types of endocrine disorders, such as polycystic ovarian syndrome (PCOS), ovarian cancer, premature ovarian failure, ovarian endometriosis, and ovarian cysts. The prevalence of ovarian-related diseases is highly vulnerable in the world. The utility of various drug delivery systems for ovarian diseases has resulted in varied success. Moreover, most of them lead to severe adverse effects and are incapable of ameliorating the signs and symptoms of the condition. Intrauterine devices (IUDs) have positioned themselves as a mechanism to deliver the drug for various ovarian-related diseases. Thereby avoiding various stability-related issues arising due to various physiological barriers of the female reproductive tract. However, the use of intrauterine devices for drug delivery to the ovaries has not been fully explored. This is attributed to the fact that they cause cysts in the ovaries and skepticism among patients and physicians. Photo-sensitive devices are an appealing approach for managing disorders affecting the ovaries. Photo-sensitive in situ forming intrauterine implants (IUIs) have several advantages, including simplicity in application, reduced invasiveness, as well as improved site-specific drug release control. Polymeric nanoparticles (PNPs) loaded with a drug may be a suitable choice to provide sustained release, alter the pharmacokinetics, and reduce the dose and dosing frequency. The current manuscript hypothesizes the utility of a PNP-loaded biodegradable photo-responsive intrauterine implantable device as an alternate novel strategy for ameliorating ovarian-related diseases.