448
S. Arthanari et al.
3 Biomedical Applications of Laser Patterned Surfaces
3.1 Biocompatibility Enhancement of Laser Patterned
Implant Materials
3.1.1 Permanent Implant Materials
The usage of the laser from nanosecond (ns) to femtosecond (fs) pulses would
produce surfaces with various textures in micro/nanoscales and enhances the in vitro
and in vivo responses of the textured surfaces. A picosecond laser texturing on AISI
420 alloy produced micro-papillae patterns with hierarchical superimposed nanostructures treated with stearic acid exhibited superhydrophobicity [12]. In addition, the
treated surfaces exhibited hardly any bacterial adhesion under stationary conditions
and resist 99 and 93% E.coli and S-aureus adhesion. The sizes of the coccoid-shaped
S.aureus and rod-shaped E.coli are 700 nm and 2 μm, respectively, which made the
colonization of the bacteria on the different micro/nano shaped surfaces. In addition
to that, the air between the water and superhydrophobic surfaces played a major
role in resisting the bacterial adhesion on the surface. These results clearly indicated
the combined effects of hierarchical superimposed micro-nano structures and the
air layer on the anti-bacterial properties. The antibacterial surfaces are essential for
metallic implant components and medical equipment. Laser ablated microstructure
coated with tetrahedral amorphous carbon (ta-C) on AISI 316L stainless steel plate
also exhibited superhydrophobic and serum-repellent properties [51]. This treatment
helped to improve the blood repellency of the surgical devices such as the scalpel
blade by forming a hydrophobic surface due to the reduced liquid-solid contact.
The laser-induced periodic surface structure (LIPSS) with different geometries and
distributions produced using a femtosecond laser on AISI 304 had precise control
on the human mesenchymal stem cell (hMSCs) attachments [52]. Furthermore, the
cells were aligned in the longitudinal direction of the LIPSS orientation and the cell
distribution and migration were controlled based on the micropatterns consisted of
nanoscale features.
Batal et al. developed 6 different treatments such as blasting, polishing, microscale texturing using nanosecond laser, micro-scale texturing using femtosecond (fs)
laser, sub-micron scale texturing using the ultra-fast laser and hydroxyapatite coatings on 67%Co-27%Cr-5%Mo (Co-Cr alloy) and investigated their wettability and
cell metabolic activities [53]. The similar groove width and depth were produced
on both ns and fs textured samples. However, ns treatment resulted in the re-cast
bulges and re-deposition of molten materials along the grid edges and intersect
regions, further the unprocessed regions were covered due to re-solidification. While
in the case of fs treatment, the untreated surface remained as such to the blasted
surface and the bottom of the grooves have consisted of self-organized hierarchical
micro/nano morphology. The fs textured surface exhibited higher hydrophilic nature
(CA ~ 0°) after 5 days of exposure and remained the same even after 30 days and
it was mainly attributed to the Wenzel state of wetting. The ns textured sample
S. Arthanari et al.
3 Biomedical Applications of Laser Patterned Surfaces
3.1 Biocompatibility Enhancement of Laser Patterned
Implant Materials
3.1.1 Permanent Implant Materials
The usage of the laser from nanosecond (ns) to femtosecond (fs) pulses would
produce surfaces with various textures in micro/nanoscales and enhances the in vitro
and in vivo responses of the textured surfaces. A picosecond laser texturing on AISI
420 alloy produced micro-papillae patterns with hierarchical superimposed nanostructures treated with stearic acid exhibited superhydrophobicity [12]. In addition, the
treated surfaces exhibited hardly any bacterial adhesion under stationary conditions
and resist 99 and 93% E.coli and S-aureus adhesion. The sizes of the coccoid-shaped
S.aureus and rod-shaped E.coli are 700 nm and 2 μm, respectively, which made the
colonization of the bacteria on the different micro/nano shaped surfaces. In addition
to that, the air between the water and superhydrophobic surfaces played a major
role in resisting the bacterial adhesion on the surface. These results clearly indicated
the combined effects of hierarchical superimposed micro-nano structures and the
air layer on the anti-bacterial properties. The antibacterial surfaces are essential for
metallic implant components and medical equipment. Laser ablated microstructure
coated with tetrahedral amorphous carbon (ta-C) on AISI 316L stainless steel plate
also exhibited superhydrophobic and serum-repellent properties [51]. This treatment
helped to improve the blood repellency of the surgical devices such as the scalpel
blade by forming a hydrophobic surface due to the reduced liquid-solid contact.
The laser-induced periodic surface structure (LIPSS) with different geometries and
distributions produced using a femtosecond laser on AISI 304 had precise control
on the human mesenchymal stem cell (hMSCs) attachments [52]. Furthermore, the
cells were aligned in the longitudinal direction of the LIPSS orientation and the cell
distribution and migration were controlled based on the micropatterns consisted of
nanoscale features.
Batal et al. developed 6 different treatments such as blasting, polishing, microscale texturing using nanosecond laser, micro-scale texturing using femtosecond (fs)
laser, sub-micron scale texturing using the ultra-fast laser and hydroxyapatite coatings on 67%Co-27%Cr-5%Mo (Co-Cr alloy) and investigated their wettability and
cell metabolic activities [53]. The similar groove width and depth were produced
on both ns and fs textured samples. However, ns treatment resulted in the re-cast
bulges and re-deposition of molten materials along the grid edges and intersect
regions, further the unprocessed regions were covered due to re-solidification. While
in the case of fs treatment, the untreated surface remained as such to the blasted
surface and the bottom of the grooves have consisted of self-organized hierarchical
micro/nano morphology. The fs textured surface exhibited higher hydrophilic nature
(CA ~ 0°) after 5 days of exposure and remained the same even after 30 days and
it was mainly attributed to the Wenzel state of wetting. The ns textured sample