Fabrication and anisotropic wettability of titanium-coated microgrooves

Abstract

Surface wettability plays a critical role in a variety of key areas including orthopaedic implants and chemical engineering. Anisotropy in wettability can arise from surface grooves, which are of particular relevance to orthopaedic implants because they can mimic collagen fibrils that are the basic components of the extracellular matrix. Titanium (Ti) and its alloys have been widely used for orthopaedic and dental implant applications. This study is concerned with the fabrication of Ti-coated microgrooves with different groove widths and the characterisation of the anisotropy in wettability through measuring water contact angles, compared with both the Wenzel and Cassie models. Experimental results revealed that there existed significant anisotropy in the wettability of Ti-coated microgrooves, and the degree of anisotropy (Δθ) increased with an increasing groove width from 5 μm to 20 μm. On average, the contact angle measured parallel to the groove direction (θ//) was about 50°–60° smaller than that measured perpendicular to the groove direction (θ⊥). In general, the Wenzel model predicted the contact angles along the surface groove direction reasonably, and so did the Cassie model for the contact angles perpendicular to the groove direction. Osteoblast spreading was affected by the anisotropy in wettability, which occurred preferably along, rather than perpendicular to, the groove direction. These findings are informative for the design of Ti implant surfaces when anisotropy in wettability matters.

In vitro contact guidance of glioblastoma cells on metallic biomaterials

“…Therefore, obtaining directional microor submicro-scaled textures on material surfaces could provide insights on the invasion pathways of GBM, which would lead to the development of enhanced therapeutic tools targeting invasion mechanisms. It should be noted that, although similar groove-like topographies can also be created via lithography or femtosecond laser techniques [46][47][48], simple tension or compression tests provide an easier way to form 3D anisotropic microstructure and topography via surface relief [2,20,21].…”

“…That is, straining from 5 to 25% leads to increase in the volume fraction of deformation markings within a grain and also results in diminished spacing between each line down to submicro-scale. Similarly, studies carried out on osteoblast cells have shown the decisive effect of the groove width on cell response [ 20 , 47 ]. These findings imply that contact guidance of micro-scale cytoplasmic protrusions GBM can be promoted along micro-scaled grooves formed with a lower degree of plastic deformation.…”

Progress in Severe Plastic Deformation of Metastable Beta Ti Alloys

“…In addition to mechanical and chemical biocompatibility of β Ti alloys, a recent study showed that SPD can be used for producing porous surfaces, which is crucial for protein adsorption and cell functions in orthopedic implants. In particular, HPT was conducted on Ti‐20Mo followed by aging at 550 °C to produce a duplex, ultrafine α/β structure . The equiaxed α particles produced were attacked more severely by etching, leading to a porous surface which enhanced cell growth and osteogenic capacity …”

“…In particular, HPT was conducted on Ti-20Mo followed by aging at 550 C to produce a duplex, ultrafine α/β structure. [75] The equiaxed α particles produced were attacked more severely by etching, leading to a porous surface which enhanced cell growth and osteogenic capacity. [75] Figure 5.…”

“…[75] The equiaxed α particles produced were attacked more severely by etching, leading to a porous surface which enhanced cell growth and osteogenic capacity. [75] Figure 5. a) Acicular α precipitated after aging at 600 C for 1 h in a β-annealed Ti-5553 alloy.…”