title: The adsorption of 99mTc(Sn)-diphosphonate complexes on tri-calciumphosphate: the influence of preparation conditions, ligand-type, incubation media and adsorption conditions. The reversibility of the adsorption.
abstract: The influence of several variables on the adsorption of 99mTc(Sn)-diphosphonate complexes on tri-calciumphosphate was determined. The composition of the incubation medium influenced the percentage adsorption: with Hank's balanced salt solution (a medium frequently used for bone cell cultures) and Tris buffer lower percentage adsorption was obtained than with physiological saline as the incubation medium. The influence of addition to the incubation medium of some ions and neutral species, some of which occur in bone fluid, is very specific. Addition of Sn(II) or Mg(II) (a component of HBSS) reduces the amount of adsorption. Addition of Ca(II) and Al(III) had no effect. Addition of sodium-citrate and MDP to the medium and an increase of the pH of the medium decreased the percentage adsorption. The ligand that was used in the preparation of the complex mixture influences the percentage adsorption considerably. The Sn(II) concentration used during the preparation of the 99mTc(Sn)-MDP and 99mTc(Sn)-MHDP complexes showed no definite influence on the percentage adsorption. The pH and ligand concentration, used in the preparation, however, did effect the percentage adsorption. It was concluded that the 99mTc(Sn)-disphosphonate mixtures are part reversibly and part irreversibly bound to tri-calcium-phosphate.
authors.affiliation: Analytical Chemistry Laboratory, State University of Utrecht, The Netherlands.
authors.forename: Y M
authors.initials: YM
authors.lastname: Huigen
authors.forename: H J
authors.initials: HJ
authors.lastname: Krips
authors.forename: S
authors.initials: S
authors.lastname: Hulleman
authors.forename: W J
authors.initials: WJ
authors.lastname: Gelsema
authors.forename: C L
authors.initials: CL
authors.lastname: De Ligny
mesh_terms: D000327:Adsorption; D002130:Calcium Phosphates; D012968:Etidronic Acid; D015609:Organotechnetium Compounds; D013669:Technetium Tc 99m Medronate / Q000031:analogs & derivatives
chemical_list: D002130:Calcium Phosphates; D015609:Organotechnetium Compounds; C485828:alpha-tricalcium phosphate; C036811:technetium Tc 99m (Sn) etidronate; C052435:technetium Tc 99m (Sn) hydroxymethylene diphosphonate; C485830:tetracalcium phosphate; C023568:technetium Tc 99m (Sn)methylenediphosphonate; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous; D012968:Etidronic Acid; D013669:Technetium Tc 99m Medronate