Binding of plasma proteins to titanium dioxide nanotubes with different diameters.
Titanium and titanium alloys are considered to be one of the most applicable materials in medical devices because of their suitable properties, most importantly high corrosion resistance and the specific combination of strength with biocompatibility. In order to improve the biocompatibility of titanium surfaces, the current report initially focuses on specifying the topography of titanium dioxide (TiO2) nanotubes (NTs) by electrochemical anodization. The zeta potential (ζ-potential) of NTs showed a negative value and confirmed the agreement between the measured and theoretically predicted dependence of ζ-potential on salt concentration, whereby the absolute value of ζ-potential diminished with increasing salt concentrations. We investigated binding of various plasma proteins with different sizes and charges using the bicinchoninic acid assay and immunofluorescence microscopy. Results showed effective and comparatively higher protein binding to NTs with 100 nm diameters (compared to 50 or 15 nm). We also showed a dose-dependent effect of serum amyloid A protein binding to NTs. These results and theoretical calculations of total available surface area for binding of proteins indicate that the largest surface area (also considering the NT lengths) is available for 100 nm NTs, with decreasing surface area for 50 and 15 nm NTs. These current investigations will have an impact on increasing the binding ability of biomedical devices in the body leading to increased durability of biomedical devices.
Laboratory of Biophysics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia.
Mukta
M
Kulkarni
Laboratory of Biophysics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia.
Ajda
A
Flašker
Laboratory of Biophysics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia.
Maruša
M
Lokar
Department of Rheumatology, University Medical Centre Ljubljana, Ljubljana, Slovenia.
Katjuša
K
Mrak-Poljšak
Department of Materials Science and Engineering, University of Erlangen Nuremberg, Erlangen, Germany.
Anca
A
Mazare
Sandoz Biopharmaceuticals Mengeš, Lek Pharmaceuticals dd, Menges, Slovenia.
Andrej
A
Artenjak
Department of Rheumatology, University Medical Centre Ljubljana, Ljubljana, Slovenia.
Saša
S
Čučnik
Department for Materials Synthesis, Institute Jožef Stefan (IJS), Ljubljana, Slovenia.
Slavko
S
Kralj
Laboratory of Biophysics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia.
Aljaž
A
Velikonja
Department of Materials Science and Engineering, University of Erlangen Nuremberg, Erlangen, Germany.
Patrik
P
Schmuki
Faculty of Health Studies, University of Ljubljana, Ljubljana, Slovenia.
Veronika
V
Kralj-Iglič
Department of Rheumatology, University Medical Centre Ljubljana, Ljubljana, Slovenia ; Faculty of Mathematics, Natural Science and Information Technology, University of Primorska, Koper, Slovenia.
Snezna
S
Sodin-Semrl
Laboratory of Biophysics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia.
Aleš
A
Iglič
D001798:Blood Proteins / Q000737:chemistry* / Q000378:metabolism*; D008422:Materials Testing; D043942:Nanotubes / Q000737:chemistry*; D010316:Particle Size; D014025:Titanium / Q000737:chemistry* / Q000378:metabolism*
D001798:Blood Proteins; C009495:titanium dioxide; D014025:Titanium
histone IIA; immunoglobulin G; protein binding; serum amyloid A; β2-glycoprotein I