Directed Irradiation Synthesis as an Advanced Plasma Technology for Surface Modification to Activate Porous and “as-received” Titanium Surfaces

Abstract

For the design of smart titanium implants, it is essential to balance the surface properties without any detrimental effect on the bulk properties of the material. Therefore, in this study, an irradiation-driven surface modification called directed irradiation synthesis (DIS) has been developed to nanopattern porous and “as-received” c.p. Ti surfaces with the aim of improving cellular viability. Nanofeatures were developed using singly-charged argon ions at 0.5 and 1.0 keV energies, incident angles from 0° to 75° degrees, and fluences up to 5.0 × 1017 cm−2. Irradiated surfaces were evaluated by scanning electron microscopy, atomic force microscopy and contact angle, observing an increased hydrophilicity (a contact angle reduction of 73.4% and 49.3%) and a higher roughness on both surfaces except for higher incident angles, which showed the smoothest surface. In-vitro studies demonstrated the biocompatibility of directed irradiation synthesis (DIS) reaching 84% and 87% cell viability levels at 1 and 7 days respectively, and a lower percentage of damaged DNA in tail compared to the control c.p. Ti. All these results confirm the potential of the DIS technique to modify complex surfaces at the nanoscale level promoting their biological performance.

Latest Trends in Surface Modification for Dental Implantology: Innovative Developments and Analytical Applications

“…Other authors have used femtosecond laser [103,104] or directed irradiation synthesis (DIS) [105,106] techniques to obtain micro-and nano-textured surfaces of titanium implants to improve osseointegration by the replication of bone structures, increasing protein attachment and therefore cell adhesion.…”

Use of Impedance Spectroscopy for the Characterization of In-Vitro Osteoblast Cell Response in Porous Titanium Bone Implants

“…On the other hand, the inherent roughness to pore wall (increase of surface contact) and surface free energy, are both considered key factors for cell adhesion, migration and differentiation [32] while inhibiting the bacterial attachment and biofilm formation [33,34]. In this context, many reports have shown the interaction between roughness and cellular response and how the microstructure and nanostructure [35] can interfere and modulate cellular adhesion, spreading and differentiation of mesenchymal stem cells [36], osteoblasts [37,38], macrophages [39,40] and osteoclast [41]. The vast majority of surface modification treatments are based on the micro and submicron scale roughness development but recently the nanotopography architecture has shown an important role for guiding bone regeneration [35].…”

“…Different techniques have been used in the literature: Archimedes, helium pycnometry, micro-tomography, image analysis [42][43][44][45] and electrical impedance spectroscopy [35,[46][47][48]. Some preliminary studies were developed using the latter technique to correlate porosity of titanium, pore size and electrical conductivity, although the influence of the electric frequency in the measured impedance was not described [35]. Furthermore, in this work, the electrochemical impedance spectroscopy is used to conclude that the pores in the porous titanium play a negative part in corrosion resistance and the flowing electrolyte can increase the corrosive rate of all titanium samples.…”

Nanotextured porous titanium scaffolds by argon ion irradiation: Toward conformal nanopatterning and improved implant osseointegration

“…As seen in Table 3, the mechanical stiffness of FD samples ($101.2 ± 0.3 GPa) is higher compared to cortical bone's ($25 GPa) and trabecular bone tissue (0.5-1 GPa). 11,46,47 This great difference is one of the main causes of stress shielding, which derives from a stiffness mismatch that induces bone resorption and can cause implant failure. 1,5 In contrast, the Young modulus of 50 vol % and 60% porous samples (2.32 and 3.97 GPa, respectively), were closer to trabecular bone young modulus.…”