Characterization and evaluation of a femtosecond laser-induced osseointegration and an anti-inflammatory structure generated on a titanium alloy

Abstract

Cell–material interactions during early osseointegration of the bone–implant interface are critical and involve crosstalk between osteoblasts and osteoclasts. The surface properties of titanium implants also play a critical role in cell–material interactions. In this study, femtosecond laser treatment and sandblasting were used to alter the surface morphology, roughness and wettability of a titanium alloy. Osteoblasts and osteoclasts were then cultured on the resulting titanium alloy disks. Four disk groups were tested: a polished titanium alloy (pTi) control; a hydrophilic micro-dislocation titanium alloy (sandblasted Ti (STi)); a hydrophobic nano-mastoid Ti alloy (femtosecond laser-treated Ti (FTi)); and a hydrophilic hierarchical hybrid micro-/nanostructured Ti alloy [femtosecond laser-treated and sandblasted Ti (FSTi)]. The titanium surface treated by the femtosecond laser and sandblasting showed higher biomineralization activity and lower cytotoxicity in simulated body fluid and lactate dehydrogenase assays. Compared to the control surface, the multifunctional titanium surface induced a better cellular response in terms of proliferation, differentiation, mineralization and collagen secretion. Further investigation of macrophage polarization revealed that increased anti-inflammatory factor secretion and decreased proinflammatory factor secretion occurred in the early response of macrophages. Based on the above results, the synergistic effect of the surface properties produced an excellent cellular response at the bone–implant interface, which was mainly reflected by the promotion of early ossteointegration and macrophage polarization.

Stereo Coverage and Overall Stiffness of Biomaterial Arrays Underly Parts of Topography Effects on Cell Adhesion

“…Surface topography, in particular, roughness is one of the significant physical cues to regulate cell behaviors . A rough surface can be obtained by laser engraving, paper grinding, alkali etching, hydrothermal reaction, and so on. Some researchers observed that cells preferentially adhere on rough surfaces, , while others report the opposite results. , Some studies led to an optimum roughness for the examined cell behaviors. , …”

Recent advances in regenerative biomaterials

“…The most widely used titanium-relevant medical alloy is Ti6Al4V, which is regarded as a good alternative material for percutaneous or transcutaneous devices owing to its high mechanical strength and excellent corrosion resistance. Like Ti implants, Ti6Al4V also needs surface modification to improve cell–material interactions for osseointegration and anti-inflammatory [ 33 , 34 ]. In particular, the biological sealing can be improved via surface modification [ 35 , 36 ].…”

Electrical Impedance of Surface Modified Porous Titanium Implants with Femtosecond Laser

“…Meanwhile, porous titanium samples were manufactured by space holder technique, with a particle size range of 100-200 µm. Ammonium hydrogen carbonate (NH 4 HCO 3 ) from (Cymit Química SL, Barcelona, Spain) was used as a space holder with different content (30,40,50, and 60 vol. %).…”

“…Femtosecond laser surface modifications on titanium and alloys substrates have been proved as a feasible tool to improve cells adhesion, differentiation, proliferation, and all together, more effectively boost osseointegration of the implant. In general, this physical modification technique allows: (1) custom design of nano-and micro-structures, such as laser induced periodically surface structure (LIPSS), ripples, columns, pits, and spikes [21][22][23], with an appropriate selection of laser beam parameters and conditions [24][25][26][27]; (2) formation of roughness with enhancement of wettability [28,29] or hydrophilicity-hydrophobicity of treated surfaces [29,30]; (3) inducing protein adsorption and following localized adhesion formation and cell shape-based mechanical restraints that promote osteogenic differentiation and hence, superior osseointegration of implants [31,32]; (4) prevention of bacterial adhesion and biofilm formation [33,34]; (5) variation of chemical composition of laser modified surfaces, for instance, bone-like apatite precipitation [35,36] and formation of nano-or micro-layers of oxides [37] such as, for example, protective TiO 2 on titanium substrates.…”