CO₂ laser surface patterning of nylon 6,6 and subsequent effects on wettability characteristics and apatite response

Abstract

Simulated body fluid has been used previously to predict the osseointegration potential of materials by assessing the apatite response. This paper details a study carried out using a CO 2 laser to induce a number of surface patterns which inherently modified both the surface chemistry and surface topography of nylon 6,6 and gave rise to a difference in apatite response. These induced patterns caused a reduction in hydrophilicity with increased contact angles of up to 10u. Following immersion in simulated body fluid for 14 days each sample was weighed revealing an increase in weight of up to 0?029 g indicating that an apatite layer had begun to form. Energy dispersive X-ray analysis identified the presence of calcium and phosphorous, two elements which support osteoblast cell response. It was found that the laser induced patterned samples gave rise to more layer crystals forming suggesting a more optimised surface for osteoblast cell growth.

The Efficacy of Laser Material Processing for Enhancing Stem Cell Adhesion and Growth on Different Materials

“…This is significant as it is stated by some researchers that highly hydrophobic materials, with high values of θ, hinder the adhesion and growth of biological cells [15]. Having said that, with the added complexity of CO2 laser processing, it is highly likely that the increase in surface roughness and increase in surface oxygen content could have given rise to a more enhanced response from the stem cells, as has been discussed previously [4,12]. This is in accord with other researchers [15,73,74] and explains the enhanced stem cell response to the CO2 laser surface engineered polyamide 6,6 samples and the CO2 laser surface engineered PTFE samples, even considering that the PTFE laser engineered samples are borderline superhydrophobic (θ>150°).…”

“…Surface profiles of each sample were determined using a non-contact confocal chromatic imaging (CCI) system (Micromesure 2; STIL S.A., France) with Surface Map software and TMS Plus software. Further details of this system can be found in [12].…”

“…[7] makes them critical for the development of biological tissues, making them an ideal candidate for use within the field of regenerative medicine [2,[7][8][9][10][11]. What is more, a number of important works have been carried out to show that biological cells [12][13][14], including MSCs [4,15,16] hold the ability to distinguish between variations in surface characteristics (such as roughness, for example), giving rise to a highly modulated biological cell growth response including variations in adhesion, protein adsorption, differentiation and proliferation. It has been suggested that the use of surface engineering technologies, to assist in the development of substrates to provide a biomimetic environment, offers a substantial approach to enhance and prolong the in vitro lifecycle of MSCs whilst still upholding the MSC's multipotency [9,17].…”

3D-MID Technology for Surface Modification of Polymer-Based Composites: A Comprehensive Review

“…The ablation of material starts when a certain value of laser fluence, the so-called ablation threshold is reached or exceeded. Therefore, the laser surface modification of materials is classified as below or above the ablation threshold [ 212 , 213 , 214 , 215 , 216 ].…”