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».

Laser processing of dental implant surfaces is becoming a more widespread replacement for classical techniques due to its undeniable advantages, including control of oxide formation and structure and surface relief at the microscale. Thus, using a laser, we created several biomimetic topographies of various shapes on the surface of titanium screw-shaped implants to research their success and survival rates. A distinctive feature of the topographies is the presence of “µ-rooms”, which are special spaces created by the depressions and elevations and are analogous to the µ-sized room in which the osteocyte will potentially live. We conducted the comparable in vivo study using dental implants with continuous (G-topography with µ-canals), discrete (S-topography with μ-cavities), and irregular (I-topography) laser-induced topographies. A histological analysis performed with the statistical method (with p-value less than 0.05) was conducted, which showed that G-topography had the highest BIC parameter and contained the highest number of mature osteocytes, indicating the best secondary stability and osseointegration.

We developed a surface design that imitates the osteon structure of human bone tissue to improve the bio-integration of a titanium implants. Two types of subcellular-sized microgrooves were formed on VT6 (analogue 6Al-4V) titanium surface by laser processing: closed and open microgrooves. An in vitro study of the proliferation of human bone marrow mesenchymal stem cells on the formed structures was carried out, osteogenic differentiation was studied.

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To prevent implant-associated infections, surface modifications need to be developed that prevent bacterial colonisation and biofilm formation. In the present study, titanium surfaces were processed by nanosecond-pulsed laser ablation to generate a variety of different structures (anatase, rutile, Osteon, as well as Osteon additionally coated with silver and clove nanoparticles). Analysis of adhesion and biofilm formation of the oral pioneer bacterium Streptococcus oralis could demonstrate antibacterial properties of anatase surfaces. For clinical translation, the effect should be enhanced by further adaption and combined with the osseointegrative Osteon structure