Effects of nanometric roughness on surface properties and fibroblast's initial cytocompatibilities of Ti6AI4V

Abstract

Titanium alloy (Ti6Al4V) has widespread medical applications because of its excellent biocompatibility. Its biological responses can further be enhanced by polishing and passivation. Unfortunately, preparing titanium alloy samples of nanometric roughness is by far much more difficult than preparing those of micrometric roughness, and numerous investigations on roughness induced effects are all focused on micrometric scales. For the remedy, we investigate, at nanometric scale, the influence of roughness on surface properties and biological responses. Six groups of Ti6Al4V with average roughness (R(a)) values of 2.75-30.34 nm are prepared. The results indicated that nanometric roughness of samples change the wettability and amphoteric OH groups. The contact angles monotonically decrease from 2.75 to 30.34 nm and the rougher surfaces lead to higher wettability. The in vitro cell-culture studies, using Murine NIH-3T3 fibroblasts, showed the spindle-shaped morphology on rougher surface compared to round∕spherical morphology on smoother surface. A cytodetacher is employed to quantitatively measure the initial adhesion force of fibroblasts to specimen. The adhesion strength of fibroblasts, ranging from 55 to 193 nN, is significantly influenced by the nanometric roughness while the surface is within the range of 2.75-30.34 nm R(a) roughness, and the adhesion strength appeared stronger for rougher surface. The cell number on the smoother surface is higher than on the rougher surface at 5-day culture. The studies indicated that nanometric roughness would alter the surface properties and further influence cell morphology, adhesion strength, and proliferation.

Soft tissue conditions and marginal bone levels of implants with a laser‐microtextured collar: a 5‐year, retrospective, controlled study

“…1), while blasted surfaces on machinetooled microthreads show random nanoroughness and somewhat sharp edges. As nano features influence fibroblast behavior and the strength of adhesion through filopodial sensing (Dalby et al 2004;Wang et al 2011), one might speculate that repetitive nanosize surface features created with a laser have the ability to allow fibroblasts to form a physical connective tissue attachment to titanium implants that restricts apical migration of gingival epithelium and preserves the coronal level of bone. While the implications of the marginal bone level are important for the stability of an implant, there are further considerations that relate to the peri-implant soft tissues.…”

In vitro response of preosteoblastic MG63 cells on Ni‐free Ti shape memory substrates

“…In our results the roughness, wettability, and surface energy did not affect the number of living‐MG63 cells attached in the substrates as the cell attachment test did not show significant differences; however, they conditioned the cell morphology as presented above. In the case of roughness, nanotopography has been a recent focus of investigations due to the fact that molecule interaction, that is the first stage on cell‐biomaterial communication, occurs at this scale 37–40. For instance, Cai et al39 and Webster et al40 have investigated the effect of roughness ( R a parameter from 2 to 40 nm) on protein absorption and cell growth and they have shown that this scale of topography is key to create biomimetic surfaces, which is still an issue in the orthopedic field.…”

“…In the case of roughness, nanotopography has been a recent focus of investigations due to the fact that molecule interaction, that is the first stage on cell-biomaterial communication, occurs at this scale. [37][38][39][40] For instance, Cai et al 39 and Webster et al 40 have investigated the effect of roughness (R a parameter from 2 to 40 nm) on protein absorption and cell growth and they have shown that this scale of topography is key to create biomimetic surfaces, which is still an issue in the orthopedic field. In the present study, the obtained results followed the trend exposed by other authors about nanometer scale topography influence on cell morphology 9,10 : the Ti19.1Nb8.8Zr alloy, which is the nano-rougher substrate, induced a flatter cell-shape and extended than the smoother one, the Ti41.2Nb6.1Zr alloy.…”

In vitro performance of ceramic coatings obtained by high velocity oxy-fuel spray

“…Different reasons support this fact. Firstly, roughness is always desirable, as the presence of a certain roughness allows a better gripping of the cell to the surface (although it is well known that nanometric roughness is preferable to micrometric one [19,20]); secondly, a higher specific surface assures a greater possibility of proliferation and a higher cell density for the same apparent surface; and finally, the more significant the quotient between the real surface and the apparent one, the higher the number of vicinities where the precipitation mechanism explained in the previous section can occur. These reasons lead to the expectation of obtaining better osteoblast behaviour for cases with a higher specific surface.…”