Preparation and evaluation of ¹⁸⁸Re sulfide colloidal nanoparticles loaded biodegradable poly (L‐lactic acid) microspheres for radioembolization therapy

Abstract

Radioembolization with radioactive microspheres has been an effective method for the treatment of liver lesions. The aim of this study was to prepare carrier-free Re loaded poly (L-lactic acid) (PLLA) microspheres through Re sulfide colloidal nanoparticles ( Re-SC nanoparticles). The formation of Re-SC nanoparticles was confirmed by ultraviolet-visible spectrophotometry. The labeling yield of Re-SC nanoparticles was verified using the RTLC method. Effects of synthesis parameters on morphology and size of prepared Re-sulfide colloidal-PLLA microspheres ( Re-SC-PLLA microspheres) were studied by scanning electron microscopy. In vitro stability of Re-SC-PLLA microspheres was investigated in normal saline at room temperature and in human serum at 37°C. In vivo distribution studies and gamma camera imaging were performed in healthy BALB/c mice. The microspheres could be prepared with sizes between 13 and 48 μm (modal value 29 μm) and radiolabeling efficiency>99%. After incubation, the microspheres were found stable in vitro up to 72 hours. The biodistribution after intravenous injection in healthy BALB/c mice showed high accumulation in lung as a first capture pathway organ for microsphere followed by great retention over 48 hours for these microspheres. These data show that Re-SC-PLLA microspheres are suitable candidate for clinical studies.

Transarterial Radioembolization (TARE) Agents beyond 90Y-Microspheres

“…They thus reported a radiolabelling efficiency of 92%. Recently, encapsulation of 188 Re-sulfur colloids in PLA microspheres by an oil in‐water (O/W) emulsion solvent extraction procedure was reported [93]. The 13-48 μ m particles were labelled with over 99% efficiency and were injected intravenously into mice, showing high lung uptake.…”

Universal Chelator-Free Radiolabeling of Organic and Inorganic-Based Nanocarriers with Diagnostic and Therapeutic Isotopes for Internal Radiotherapy

“…Radioactive metals such as 99m Tc ( T 1/2 = 6 h, E y = 140 keV) and 188 Re ( T 1/2 = 17 h, E y = 2.12 MeV, penetration distance = 3.8 mm) are widely used in clinical practice for diagnostic and therapeutic purposes. , 99m Tc is a diagnostic γ emitter and can be detected by SPECT-CT, while 188 Re is a therapeutic β emitter and has great therapeutic potential for internal radiotherapy. According to previous works, − SnCl 2 is generally used as a reducing agent for the radiolabeling of NPs and is usually added to [ 99m Tc]­TcO 4 – or [ 188 Re]­ReO 4 – solutions. The radiolabeling protocol of the developed NPs was optimized for 188 Re.…”

Diagnostic Performance of Theranostic Radionuclides Used in Transarterial Radioembolization for Liver Cancer

“…A study of 10 patients (3 patients with unresectable colorectal liver metastases and 7 patients with hepatocellular cancer), who received treatment with 188 Re-human serum albumin MSs, displayed considerable survival rates and tolerable toxicity ( 26 ). Other reported 188 Re-MSs include 188 Re-PLGA ( 27 ), 188 Re-poly(L-lactic acid) (PLLA) ( 28 ), 188 Re-glass-MSs, and 188 Re-resin-MSs.…”