PURPOSE: The aim of the present work was to perform the labelling of granulocytes by their engulfment with chitosan-coated magnetic (64)Cu nanoparticles (MNPs) in order to obtain a radiopharmaceutical suitable for dual imaging (PET-MRI) of inflammatory/infective diseases. PROCEDURES: Specimens of 5-20 mg MNPs were washed with saline-isotonic solution and recuperated by magnetic decantation; 15-58 μg Cu(2+) (CuCl(2)·H(2)O) in 50 μl of acidified (pH 5.5) saline solution was added to the MNPs re-suspended saline-isotonic solution; 10 mg MNPs was allowed to react with 16 μg (64)Cu [(64)Ni(p,n) at 12-9 MeV] followed by anion exchange chromatography with a specific activity of 56 MBq/μg. Pellets of granulocytes were obtained from peripheral blood; MNPs engulfment by granulocytes was obtained and granulocyte-engulfed viability was assessed by the trypan blue exclusion (TBE) test performed at 5 min, 2 h and 4 h; assessment of the release of (64)Cu from labelled granulocytes in plasma was performed by measuring the radioactivity of both the cellular pellet and the supernatant solution. RESULTS: Our data showed the binding capacity of chitosan-coated MNPs for cationic metal. The amount of Cu(+2) chelated captured per milligram of MNPs was constant and independent of the reagent concentrations. In all cases, more than 90% of the engulfed granulocytes were positive to the TBE test. The MNPs were localised within the cells. CONCLUSION: In our in vitro model, MNPs are taken up by granulocytes through phagocytosis, whereas previously described methods were based on the use of a chelating agent that permit Cu to cross the cell membrane. Moreover, the (64)Cu-engulfed granulocytes showed a high stability of up to 80% of retained radioactivity after 24 h of incubation.
PURPOSE: The aim of the present work was to perform the labelling of granulocytes by their engulfment with chitosan-coated magnetic (64)Cu nanoparticles (MNPs) in order to obtain a radiopharmaceutical suitable for dual imaging (PET-MRI) of inflammatory/infective diseases. PROCEDURES: Specimens of 5-20 mg MNPs were washed with saline-isotonic solution and recuperated by magnetic decantation; 15-58 μg Cu(2+) (CuCl(2)·H(2)O) in 50 μl of acidified (pH 5.5) saline solution was added to the MNPs re-suspended saline-isotonic solution; 10 mg MNPs was allowed to react with 16 μg (64)Cu [(64)Ni(p,n) at 12-9 MeV] followed by anion exchange chromatography with a specific activity of 56 MBq/μg. Pellets of granulocytes were obtained from peripheral blood; MNPs engulfment by granulocytes was obtained and granulocyte-engulfed viability was assessed by the trypan blue exclusion (TBE) test performed at 5 min, 2 h and 4 h; assessment of the release of (64)Cu from labelled granulocytes in plasma was performed by measuring the radioactivity of both the cellular pellet and the supernatant solution. RESULTS: Our data showed the binding capacity of chitosan-coated MNPs for cationic metal. The amount of Cu(+2) chelated captured per milligram of MNPs was constant and independent of the reagent concentrations. In all cases, more than 90% of the engulfed granulocytes were positive to the TBE test. The MNPs were localised within the cells. CONCLUSION: In our in vitro model, MNPs are taken up by granulocytes through phagocytosis, whereas previously described methods were based on the use of a chelating agent that permit Cu to cross the cell membrane. Moreover, the (64)Cu-engulfed granulocytes showed a high stability of up to 80% of retained radioactivity after 24 h of incubation.
Authors: Chenjie Xu; Jin Xie; Don Ho; Chao Wang; Nathan Kohler; Edward G Walsh; Jeffrey R Morgan; Y Eugene Chin; Shouheng Sun Journal: Angew Chem Int Ed Engl Date: 2008 Impact factor: 15.336
Authors: M Fairclough; C Prenant; B Ellis; H Boutin; A McMahon; G Brown; P Locatelli; A K P Jones Journal: J Labelled Comp Radiopharm Date: 2016-04-08 Impact factor: 1.921