title: Selective in vitro labeling of white blood cells using 99mTc-labeled liposomes.
abstract: We describe a method by which endocytosis-based radiolabeling of WBC is achieved using 99mTc-liposomes of optimal size and charge, and of a composition that assures both in vitro (whole blood) and intracellular stability of the radiopharmaceutical. In our study, excellent in vitro stability of 99mTc-liposomes with 95% labeling efficiency was observed with >90% stability up to 6 h and a minimum of 85% after 24 h of incubation either in normal saline or serum. Total WBC labeling efficiency using 99mTc-liposomes determined by radio-thin layer chromatographic analysis was 30.6 +/- 2.21%, 20.89 +/- 1.31% for monocytes and 9.7 +/- 1.74% for polymorphonuclears. Negligible activity was bound to red blood cells. The procedure did not affect the cell viability and the separation of the free 99mTc-liposomes from the cells was done by centrifugation.
authors.affiliation: The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Andreopoulos
authors.forename: Leela P
authors.initials: LP
authors.lastname: Kasi
authors.forename: Panayiotis J
authors.initials: PJ
authors.lastname: Asimacopoulos
authors.forename: Satish G
authors.initials: SG
authors.lastname: Jhingran
authors.forename: William
authors.initials: W
authors.lastname: Cole
authors.forename: David
authors.initials: D
authors.lastname: Yang
authors.forename: E Edmund
authors.initials: EE
authors.lastname: Kim
mesh_terms: D001711:Biotransformation; D002470:Cell Survival; D004705:Endocytosis / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D007553:Isotope Labeling / Q000379:methods*; D007962:Leukocytes / Q000000981:diagnostic imaging* / Q000502:physiology*; D008081:Liposomes / Q000378:metabolism*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000097:blood; D013670:Sodium Pertechnetate Tc 99m / Q000097:blood*
chemical_list: D008081:Liposomes; D019275:Radiopharmaceuticals; D013670:Sodium Pertechnetate Tc 99m