Titanium surface hydrophilicity enhances platelet activation

Abstract

Titanium implant surface modification is a key strategy used to enhance osseointegration. Platelets are the first cells that interact with the implant surface whereupon they release a wide array of proteins that influence the subsequent healing process. This study therefore investigated the effect of titanium surface modification on the attachment and activation of human platelets. The surface characteristics of three titanium surfaces: smooth (SMO), micro-rough (SLA) and hydrophilic micro-rough (SLActive) and the subsequent attachment and activation of platelets following exposure to these surfaces were determined. The SLActive surface showed the presence of significant nanoscale topographical features. While attached platelets appeared to be morphologically similar, significantly fewer platelets attached to the SLActive surface compared to both the SMO and SLA surfaces. The SLActive surface however induced the release of the higher levels of chemokines β-thromboglobulin and platelet factor 4 from platelets. This study shows that titanium surface topography and chemistry have a significant effect on platelet activation and chemokine release.

Enhanced differentiation of human osteoblasts on Ti surfaces pre-treated with human whole blood

“…In this study, early interaction between blood and the 33 implant surface and how this affects the mechanism of osseointegration were investigated. For this, blood 34 coagulation on a micro-roughened hydrophobic titanium (Ti) surface (SLA-H phob ) and on a hydrophilic 35 micro-roughened Ti surface with nanostructures (SLActive-H phil NS), as well as the effects of whole 36 human blood pre-incubation of these two surfaces on the differentiation potential of primary human 37 bone cells (HBC) was assessed. Interestingly, pre-incubation with blood resulted in a dense fibrin network 38 over the entire surface on SLActive-H phil NS but only in single patches of fibrin and small isolated fibre 39 complexes on SLA-H phob .…”

“…This is of crucial impor-94 tance, since migration of osteoblastic cells occurs through the pro-95 visional fibrin scaffold to reach the protein layer on the implant 96 [31]. 97 Several studies investigated the influence of topographical 98 [32][33][34][35] and physiochemical [36][37][38] Ti surface properties on the 99 adsorption of plasma proteins, the induction of the blood coagula-100 tion cascade and blood-cell adhesion. In particular it was shown 101 that blood clot formation was enhanced on super-hydrophilic Ti 102 surfaces, leading to a dense fibrin network, whereas on hydropho-103 bic Ti surfaces only a thin, non-structured network was observed 104 [37,[39][40][41].…”

Biological responses of human bone mesenchymal stem cells to Ti and TiZr implant materials

“…29,30 As mentioned above, excellent osseointegration was determined not only by the implant material but also by the surface topography and chemical composition of the implant. 37 From Table 1, the mean surface roughness values were greater on SLActive substrates (around 2 μm) compared with SLA substrates (around 1 μm). 31 Following processing, blood containing a high amount of organic components can adhere more rapidly to the hydrophilic surfaces.…”

“…From Table 2 and the AFM 3D images, all surfaces were irregular and rough with uneven peak-to-valley structures, and roughness values of all surfaces were close to 1 μm. 13,14,[37][38][39] Hydroxylation/hydration increases the surface energy/wettability of the implant surface. 43 A moderate surface roughness can promote cell adhesion, differentiation, and the formation of cell matrices.…”

Effects of alkaline treatment for fibroblastic adhesion on titanium

“…[101112] Current studies in human bone marrow-derived mesenchymal cells have demonstrated an increase in the gene expression levels of the markers and transcription runt-related factor 2, with bone sialoprotein also observed. [11] In vitro tests show higher cell adhesion on hydrophilic surfaces such as photocatalysis[513] compared to anodized coating with calcium phosphate on hydrophobic surfaces.…”