Probing the nanoadhesion of Streptococcus sanguinis to titanium implant surfaces by atomic force microscopy.
As titanium (Ti) continues to be utilized in great extent for the fabrication of artificial implants, it is important to understand the crucial bacterium-Ti interaction occurring during the initial phases of biofilm formation. By employing a single-cell force spectroscopy technique, the nanoadhesive interactions between the early-colonizing Streptococcus sanguinis and a clinically analogous smooth Ti substrate were explored. Mean adhesion forces between S. sanguinis and Ti were found to be 0.32±0.00, 1.07±0.06, and 4.85±0.56 nN for 0, 1, and 60 seconds contact times, respectively; while adhesion work values were reported at 19.28±2.38, 104.60±7.02, and 1,317.26±197.69 aJ for 0, 1, and 60 seconds, respectively. At 60 seconds surface delays, minor-rupture events were modeled with the worm-like chain model yielding an average contour length of 668±12 nm. The mean force for S. sanguinis minor-detachment events was 1.84±0.64 nN, and Poisson analysis decoupled this value into a short-range force component of -1.60±0.34 nN and a long-range force component of -0.55±0.47 nN. Furthermore, a solution of 2 mg/mL chlorhexidine was found to increase adhesion between the bacterial probe and substrate. Overall, single-cell force spectroscopy of living S. sanguinis cells proved to be a reliable way to characterize early-bacterial adhesion onto machined Ti implant surfaces at the nanoscale.
Department of Biomaterials and Tissue Engineering, University College London, London, UK.
Sebastian
S
Aguayo
Periodontology Unit, University College London, London, UK.
Nikolaos
N
Donos
Division of Microbial Diseases, UCL Eastman Dental Institute, University College London, London, UK.
Dave
D
Spratt
Department of Biomaterials and Tissue Engineering, University College London, London, UK.
Laurent
L
Bozec
D001422:Bacterial Adhesion / Q000187:drug effects*; D002710:Chlorhexidine / Q000494:pharmacology; D006801:Humans; D018625:Microscopy, Atomic Force / Q000379:methods*; D019736:Prostheses and Implants / Q000382:microbiology*; D013291:Streptococcus / Q000187:drug effects / Q000502:physiology*; D013499:Surface Properties; D014025:Titanium / Q000494:pharmacology*
D014025:Titanium; D002710:Chlorhexidine
atomic force microscopy; bacterial adhesion; biophysics; dental implants; titanium