Novel 175Yb-Poly (L-lactic acid) microspheres for transarterial radioembolization of unrespectable hepatocellular carcinoma

Novel biodegradable Poly (L-lactic acid) (PLLA) microspheres containing ytterbium were designed for intra-tumoral radiotherapy, especially for radioembolization. 175Yb possess both therapeutic beta and diagnostic gamma radiations. In this work, process to make ready radiomicrospheres 175Yb(acac)3-loaded PLLA for more consideration has been investigated. The radiomicrospheres were prepared with approximate size of 20-40 µm, and radionuclidic purity > 92%. The radiomicrospheres were stable in vitro for up to 72 h in normal saline, and also in human serum albumin (HSA). Biodistribution in mice bearing 4T1 tumor showed specific radionuclide uptake over 48 h. Tumor necrosis was also observed at the injection site up to 12 days after injection. These data showed that 175Yb-PLLA microspheres could be prepared and considered further for radiomicrospheres tumor therapy.