Preparation of iodine-131 labeled Polyvinyl alcohol-collagen microspheres for radioembolization therapy of liver tumors

Transarterial radioembolization using radionuclide-labeled microspheres has shown efficacy in the treatment of hepatocellular carcinoma (HCC). In this study, a novel formulation of Polyvinyl alcohol-collagen microspheres (PCMs) with an optimal settling rate is developed. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses confirm that the PCMs have uniform morphology with diameters ranging from 20 to 30 μm. These microspheres are successfully labeled with ¹³¹I, exhibiting good in vitro stability. Subsequently, ¹³¹I-labeled PCMs are administered via the hepatic artery into rats with orthotopic HCC, leading to a significant increase in median overall survival (p < 0.05). Single photon emission computed tomography (SPECT/CT) imaging and immunohistochemical assessments demonstrate precise biodistribution and stable retention of ¹³¹I-PCMs in the liver for up to 14 days. Magnetic resonance imaging (MRI) further reveals the inhibition of tumor growth following ¹³¹I-PCM treatment. In summary, the ¹³¹I-PCMs display high radiolabeling efficiency, stability, and a promising radioembolization effect in the orthotopic HCC rodent model, highlighting their potential for use in interventional cancer therapy.