Nanoceria-PAN Composite-Based Advanced Sorbent Material: A Major Step Forward in the Field of Clinical-Grade 68Ge/68Ga Generator

The Ge-68/Ga-68 generator has high potential for clinical positron emission tomography (PET) imaging. However, because of the unavailability of a suitable sorbent material, the commercially available Ge-68/Ga-68 generators are not directly adaptable for the preparation of Ga-68-labeled radiopharmaceuticals. In view of this, a new nanoceria-polyacrylonitrile (PAN) composite sorbent has been synthesized by decomposition of a cerium oxalate precursor to cerium oxide and its subsequent incorporation in PAN matrix for the development of a clinical grade Ge-68/Ga-68 generator. The X-ray diffraction (XRD) studies and BET nitrogen adsorption technique revealed that nanocrystalline ceria had an average particle size of similar to 10 nm, surface area of 72 +/- 3 m(2)/g and an average pore size of 3.8 +/- 0.1 angstrom. Investigation of the distribution ratio (K-d) values for the prepared sorbent in 0.01 N HCl medium revealed the suitability of the sorbent for the quantitative retention of Ge-68 and efficient elution of clinical grade Ga-68. A 370 MBq (10 mCi) Ge-68/Ga-68 chromatographic generator was developed using this sorbent. Ga-68 could be regularly eluted from this generator with >80% elution yield. The eluted Ga-68 possess high radionuclidic purity (<1 x 10(-5)% of Ge-68 impurity), chemical purity (<0.1 ppm of Ce, Fe and Mn ions) and was amenable for the preparation of Ga-68-labeled radiopharmaceuticals. The generator gave a consistent performance with respect to the elution yield and purity of Ga-68 over an extended period of 7 months.