Design synthesis of Y-90 glass microspheres and study of their therapeutic effects on mouse liver cancer cell line Hep3B

[90Y]Yttria Alumino Silicate Glass Microspheres: A Biosimilar Formulation to "TheraSphere" for Cost-Effective Treatment of Liver Cancer

Background: Selective internal radiation therapy (SIRT) using a suitable β--emitting radionuclide is a promising treatment modality for unresectable liver carcinoma. Yttrium-90 (90Y) [T1/2 = 64.2 h, Eβ(max) = 2.28 MeV, no detectable γ-photon] is the most preferred radioisotope for SIRT owing to its favorable decay characteristics. Objective: The present study describes indigenous development and evaluation of intrinsically radiolabeled [90Y]yttria alumino silicate ([90Y]YAS) glass microsphere, a formulation biosimilar to "TheraSphere" (commercially available, U.S. FDA-approved formulation), for SIRT of unresectable liver carcinoma in human patients. Methods: YAS glass microspheres of composition 40Y2O3-20Al2O3-40SiO2 (w/w) and diameter ranging between 20 and 36 μm were synthesized with almost 100% conversion efficiency and >99% sphericity. Intrinsically labeled [90Y]YAS glass microspheres were produced by thermal neutron irradiation of cold YAS glass microspheres in a research reactor. Subsequent to in vitro evaluations and in vivo studies in healthy Wistar rats, customized doses of [90Y]YAS glass microspheres were administered in human patients. Results: [90Y]YAS glass microspheres were produced with 137.7 ± 8.6 MBq/mg YAS glass (∼6800 Bq per microsphere) specific activity and 99.94% ± 0.02% radionuclidic purity at the end of irradiation. The formulation exhibited excellent in vitro stability in human serum and showed >97% retention in the liver up to 7 d post-administration when biodistribution studies were carried out in healthy Wistar rats. Yttrium-90 positron emission tomography scans recorded at different time points post-administration of customized dose of [90Y]YAS glass microspheres in human patients showed near-quantitative retention of the formulation in the injected lobe. Conclusions: The study confirmed the suitability of indigenously prepared [90Y]YAS glass microspheres for clinical use in the treatment of unresectable hepatocellular carcinoma.

153Sm-labeled Fe3O4@lapatinib nanoparticles as a potential therapeutic agent for breast cancer: synthesis, quality control, and in vivo evaluation

The present study introduces Fe3O4-coated lapatinib-labeled 153Sm nanoparticles (denoted as Fe3O4@lapatinib-153Sm) as a promising avenue for advancing breast cancer treatment. The radiolabeled nanoparticles combine various attributes, offering enhanced therapeutic precision. The integration of lapatinib confers therapeutic effects and targeted delivery. The inherent magnetic characteristics of Fe3O4 nanoparticles contribute to improved imaging contrast and targeted localization. Incorporating the gamma-emitting 153Sm isotope permits single-photon emission computed tomography imaging and radiation dose evaluation, while its beta-emitting nature ensures targeted cancer cell eradication. The synthesis of Fe3O4@lapatinib-153Sm was meticulously optimized by investigating the effects of parameters on radiolabeling efficiency. Physicochemical attributes were scrutinized using several analytical techniques. In-depth in vivo assessment evaluated the biocompatibility, toxicity, and biodistribution in a murine model, illuminating clinical utility. Optimal conditions (153SmCl3 concentration of 10 mCi mL-1, pH 7.4, a reaction time of 30 min, and a temperature of 25 °C) achieved >99% labeling efficiency and radiochemical purity. The TEM analysis indicated that the diameter of Fe3O4@lapatinib-153Sm nanoparticles ranged from 10 to 40 nm. Vibrating-sample magnetometry verified their superparamagnetic behaviour with a saturation magnetization of 41.4 emu g-1. The synthesized radiopharmaceutical exhibited high sterility and in vitro stability. Acute toxicity studies showed the mild effects of Fe3O4@lapatinib-153Sm at a dose of 20 mCi kg-1, with no observed mortality. Notably, lesions from Fe3O4@lapatinib-153Sm use recovered naturally over time. Radiation doses below 20 mCi kg-1 were recommended for clinical trials. The biodistribution study in BT474 xenograft mice revealed rapid clearance of Fe3O4@lapatinib-153Sm within 48 h. Significant accumulation occurred in the liver, spleen, and tumor tissue, while minimal accumulation was found in other tissues. Future steps involve studying biocorona formation and therapeutic efficacy on tumour models, refining its clinical potential.

Microspheres as a Carrier System for Therapeutic Embolization Procedures: Achievements and Advances

The targeted delivery of anti-cancer drugs and isotopes is one of the most pursued goals in anti-cancer therapy. One of the prime examples of such an application is the intra-arterial injection of microspheres containing cytostatic drugs or radioisotopes during hepatic embolization procedures. Therapy based on the application of microspheres revolves around vascular occlusion, complemented with local therapy in the form of trans-arterial chemoembolization (TACE) or radioembolization (TARE). The broadest implementation of these embolization strategies currently lies within the treatment of untreatable hepatocellular cancer (HCC) and metastatic colorectal cancer. This review aims to describe the state-of-the-art TACE and TARE technologies investigated in the clinical setting for HCC and addresses current trials and new developments. In addition, chemical properties and advancements in microsphere carrier systems are evaluated, and possible improvements in embolization therapy based on the modification of and functionalization with therapeutical loads are explored.