Surface Modification of Titanium by Femtosecond Laser in Reducing Bacterial Colonization

Abstract

In the past few decades, titanium and its alloys have been widely used in the orthopaedic field. However, because titanium is bioinert and lacks antibacterial properties, infection may happen when bacteria attach to implant surfaces and form biofilms. It has been studied that some naturally existing micron-scale topographies can reduce bacterial attachment such as cicada wings and gecko skins. The aim of this in vitro study was to find an implant with good biocompatibility and antimicrobial properties by the modification of micron-scale topographies. In this paper, a femtosecond laser was used to provide microtopography coatings on Ti substrates. The surface morphology of Ti substrates was observed by scanning electron microscopy (SEM). XPS was used to fulfil the chemical compositional analysis. The surface wettability was measured by contact angle measurement system. The effect of microtopography coatings with different surface microstructures on bacterial activities and bone marrow mesenchymal stem cells (BMSC) functions was investigated. The results of in vitro study revealed that microtopography coatings restrain the adhesion of Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis), which are common pathogens of orthopaedic implant infections. In addition, microtopography coatings stimulated BMSC adhesion and proliferation. Our studies suggest that a microtopography-coated sample modified by femtosecond laser showed promising antibacterial properties and favourable biocompatibility. The femtosecond laser technique provides an accurate and valid way to produce microtopography coatings with outstanding biocompatibility and antimicrobial properties, and could be widely used to modify the surface of orthopaedic metal implants with great potential.

Investigating Potential Effects of Ultra-Short Laser-Textured Porous Poly-ε-Caprolactone Scaffolds on Bacterial Adhesion and Bone Cell Metabolism

“…Nevertheless, within the observed inhibitory effects, significant differences were noted in the behavior of the two species on the PCL surfaces, namely a high proliferation growth rate of E. coli compared to that of S. aureus. Previous studies also reported that bacterial responses to underlying surface topography are highly species-and strain-dependent, including in femtosecond-laser-modified surfaces [52,54]. These differences in the antibacterial activity of S. aureus and E. coli are related to the structure and composition of the cell wall in Gram-positive and negative bacteria.…”

“…Antibacterial activity associated with topographical features is advantageous for its long-term effects as it retains its anti-adhesive effects and/or elicits mechano-inhibitory effects after bacteria attachment, i.e., morphological abnormalities and cell lysis [51]. Femtosecond-laser-induced microtopographies have been reported to influence bacterial cell attachment, colonization, and biofilm formation for both Gram-positive and Gram-negative bacteria [52][53][54]. Furthermore, the type of laser-induced pattern (such as pillar-like, honeycomb, etc.)…”

Design and Properties of Antimicrobial Biomaterials Surfaces

“…Laser surface treatment is also effective for metallic materials. [172][173][174][175] Boinovich et al [59] have produced superhydrophilic and superhydrophobic structures. The former is more effective against E. coli due to stronger adhesion between the rough laser-treated surface and bacteria cell wall, which results in high tension and cell wall rupturing.…”

“…Laser surface treatment is also effective for metallic materials. [ 172–175 ] Boinovich et al. [ 59 ] have produced superhydrophilic and superhydrophobic structures.…”

Optical parameters impact on glass-to-metal welding

“…where 𝑁 is the number of pulses acting on the same spot. For the sake of compactness, instead of writing two different linear regression models [14], [15], it is possible to formulate equations (3)-( 4), in a comprehensive way [16] as follows:…”