title: Titanium release in serum of patients with different bone fixation implants and its interaction with serum biomolecules at physiological levels.
abstract: Increased concentrations of circulating metal-degradation products derived from the use of Ti orthopaedic implants may have deleterious biological effects over the long term. Therefore, there is an increasing need to establish the basal level of Ti in the serum of the population (exposed and non-exposed) with appropriate highly sensitive techniques and strategies. With this aim, we have developed a quantitative strategy for the determination of total Ti concentration in human serum samples by isotope dilution analysis using a double-focussing inductively coupled plasma mass spectrometer. Minimizing sample handling and therefore contamination issues, we obtained detection limits of about 0.05 μg L(-1) Ti working at medium resolution (m/Δm 4000). Such extremely good sensitivity permitted us to establish the range of Ti concentration in serum of 40 control individuals (mean 0.26 μg L(-1)) and also to compare it with the level in exposed patients with different Ti metal implants. On the other hand, Ti transport "in vivo" studies have been enabled by online coupling of liquid chromatography (anion-exchange) separation and double-focussing inductively coupled plasma mass spectrometry for sensitive detection of Ti. The development of a postcolumn isotope dilution strategy permitted quantitative characterization of the Ti-transporting biomolecules in human serum. The results for unspiked serum revealed that 99.8% of the Ti present in this fluid is bound to the protein transferrin, with column recoveries greater than 95%.
authors.affiliation: Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Oviedo, Spain.
authors.forename: Yoana
authors.initials: Y
authors.lastname: Nuevo-Ordóñez
authors.forename: M
authors.initials: M
authors.lastname: Montes-Bayón
authors.forename: E
authors.initials: E
authors.lastname: Blanco-González
authors.forename: J
authors.initials: J
authors.lastname: Paz-Aparicio
authors.forename: J Diánez
authors.initials: JD
authors.lastname: Raimundez
authors.forename: J M
authors.initials: JM
authors.lastname: Tejerina
authors.forename: M A
authors.initials: MA
authors.lastname: Peña
authors.forename: A
authors.initials: A
authors.lastname: Sanz-Medel
mesh_terms: D001842:Bone and Bones / Q000187:drug effects / Q000601:surgery; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002852:Chromatography, Ion Exchange / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D019736:Prostheses and Implants / Q000009:adverse effects; D011485:Protein Binding; D011865:Radioisotope Dilution Technique; D011868:Radioisotopes / Q000097:blood* / Q000737:chemistry; D012015:Reference Standards; D015203:Reproducibility of Results; D013054:Spectrophotometry, Atomic / Q000379:methods*; D014025:Titanium / Q000097:blood*; D014168:Transferrin / Q000032:analysis* / Q000378:metabolism
chemical_list: D011868:Radioisotopes; D014168:Transferrin; D014025:Titanium