eCM (Eur Cell Mater / e Cells & Materials) eCM Open Access Scientific Journal
 ISSN:1473-2262         NLM:100973416 (link)         DOI:10.22203/eCM

2011   Volume No 21 – pages 430-444

Title: Alkali treatment of microrough titanium surfaces affects macrophage/monocyte adhesion, platelet activation and architecture of blood clot formation

Author: V Milleret, S Tugulu, F Schlottig, H Hall

Address: Cells and BioMaterials, Department of Materials, ETH Zürich, Wolfgang Pauli Strasse 10, HCI E415, 8093 Zurich, Switzerland

E-mail: heike.hall at mat.ethz.ch

Key Words: SBA Ti surfaces, alkali treatment, hemocompatibility, blood clot formation, fibrin fibers, platelet activation.

Publication date: May 22nd 2011

Abstract: Titanium implants are most commonly used for bone augmentation and replacement due to their favorable osseointegration properties. Here, hyperhydrophilic sand-blasted and acid-etched (SBA) titanium surfaces were produced by alkali treatment and their responses to partially heparinized whole human blood were analyzed. Blood clot formation, platelet activation and activation of the complement system was analyzed revealing that exposure time between blood and the material surface is crucial as increasing exposure time results in higher amount of activated platelets, more blood clots formed and stronger complement activation. In contrast, the number of macrophages/monocytes found on alkali-treated surfaces was significantly reduced as compared to untreated SBA Ti surfaces. Interestingly, when comparing untreated to modified SBA Ti surfaces very different blood clots formed on their surfaces. On untreated Ti surfaces blood clots remain thin (below 15 mm), patchy and non-structured lacking large fibrin fiber networks whereas blood clots on differentiated surfaces assemble in an organized and layered architecture of more than 30 mm thickness. Close to the material surface most nucleated cells adhere, above large amounts of non-nucleated platelets remain entrapped within a dense fibrin fiber network providing a continuous cover of the entire surface. These findings might indicate that, combined with findings of previous in vivo studies demonstrating that alkali-treated SBA Ti surfaces perform better in terms of osseointegration, a continuous and structured layer of blood components on the blood-facing surface supports later tissue integration of an endosseous implant.

Article download: Pages 430-444 (PDF file)
DOI: 10.22203/eCM.v021a32

Animation 1 files (*.avi): z-stacks of confocal laser scanning micrographs of untreated (A) and alkali-treated (B) SBA Ti surfaces after 2 h of incubation in partially heparinized human whole blood at 37 °C. Samples were stained with Hoechst (blue) for nuclei, with phalloidin-Alexa 488 conjugate (green) for actin and with anti-fibrin-(red) for fibrin fibers. The z-stacks start at the surface (0 µm) and every 150 nm an image was acquired until the entire thickness of the blood clots was imaged.

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Movie file A
Movie file B