Laser-assisted fabrication and in vitro verification of functionalized surface for cells biointegration

Abstract

The paper investigates how the surface relief of an implant affects cell behavior. Currently, most implant manufacturers claim the key impact biocompatibility factor to be surface micro-roughness. We suppose that the interaction between cells and implants also depends on such relief peculiarities as continuous or discontinuous topography, subcellular distance between peaks and presence of porous oxide layer. We have developed the laser processing conditions that provide three different reliefs: «open grooves», «grid» and «close grooves». Along with the micro-roughness characteristics the reliefs differ with their deepness and period of grooves. The surface composition analysis results have shown a sandwich structure consisting of Ti → TiO → Ti 2 O 3 Nx → TiO 2 (anatase) → TiO 2 (rutile). The wettability study has demonstrated superhydrophilicity (CA is 0 • ) for all reliefs. The quantitative and qualitative analysis of hMSCs proliferation and osteogenic differentiation was performed for 20 days. In vitro study has revealed the topography affects the spatial orientation of cells. The shape and size of the cell nuclei vary with different topographies. We have found continuous «open grooves» structures with the subcellular to cellular period are beneficial for cells' life-sustaining activity. Discontinuous «grid» structures with individual slots might not provide cells with mobility with the least external mechanical effect compared to «open grooves».

Innovative surfaces and alloys for dental implants: What about biointerface-safety concerns?

“…In order to maintain a textured pattern with well-ordered peaks and valleys at the micro-or nanoscale, some researchers described the use of laser-induced surface treatments [36][37][38].…”

“…With the application of laser processing, identical and constant morphologies could be manufactured, providing better cell adhesion and proliferation along surfaces [36]. Zwarh et al showed the confection of complex morphologies on Ti surfaces with the application of direct laser interference patterning (DLIP), thus demonstrating a 16% increase in the viability of osteogenic cells, when compared with standard surface treatments (sand-blasted/acid-etched) [37].…”

Laser-Induced µ-Rooms for Osteocytes on Implant Surface: An In Vivo Study

“…In recent studies on laser surface treatment of materials, it has been shown that the geometric shape of the surface, the size of pattern elements, and surface oxides affect adhesion [ 36 , 37 , 38 ], orientation angle [ 29 , 39 , 40 ], and differentiation and proliferation [ 37 , 41 , 42 , 43 , 44 ] of various types of cells. For example, it was shown during experiments on human osteosarcoma (HOS) cells [ 40 ] that a polished surface and a rough surface with non-periodic relief contribute to random orientation of cells, and it was found that cell spreading decreases with the increase of surface roughness.…”

“…We also included a third type of topography in the study: irregular topography (I-topography in Figure 1 ), which is the most-studied today. The results of in vitro study of these topographies are presented in the work of Veiko et al [ 41 ].…”

On-Demand Wettability via Combining fs Laser Surface Structuring and Thermal Post-Treatment

“…One of the areas of interest for fs laser use is the possibility to induce highly controllable features on the surfaces of various materials for potential wettability control [ 4 ]. Overall, surfaces with controlled wettability properties can be produced in numerous ways, including various coatings or lasers with longer (for instance nanosceond) pulses [ 5 , 6 , 7 ]. Ultrashort pulse lasers offer a potential advantage of a higher degree of control of the thermal aspect of the process.…”