Bimetallic Nanowires on Laser-Patterned PEN as Promising Biomaterials

Abstract

As inflammation frequently occurs after the implantation of a medical device, biocompatible, antibacterial materials must be used. Polymer–metal nanocomposites are promising materials. Here we prepared enhanced polyethylene naphthalate (PEN) using surface modification techniques and investigated its suitability for biomedical applications. The PEN was modified by a KrF laser forming periodic ripple patterns with specific surface characteristics. Next, Au/Ag nanowires were deposited onto the patterned PEN using vacuum evaporation. Atomic force microscopy confirmed that the surface morphology of the modified PEN changed accordingly with the incidence angle of the laser beam. Energy-dispersive X-ray spectroscopy showed that the distribution of the selected metals was dependent on the evaporation technique. Our bimetallic nanowires appear to be promising antibacterial agents due to the presence of antibacterial noble metals. The antibacterial effect of the prepared Au/Ag nanowires against E. coli and S. epidermidis was demonstrated using 24 h incubation with a drop plate test. Moreover, a WST-1 cytotoxicity test that was performed to determine the toxicity of the nanowires showed that the materials could be considered non-toxic. Collectively, these results suggest that prepared Au/Ag nanostructures are effective, biocompatible surface coatings for use in medical devices.

Engineered Cu-PEN Composites at the Nanoscale: Preparation and Characterisation

“…It is obvious from Figure 1 that the pristine PEN showed a flat surface with a surface roughness of 4.27 nm. After laser modification, the polymer surface was transformed into coherent ripple structures (LIPSS) with pronounced surface roughness [ 22 , 24 , 39 ]. This dramatic change was related to the LIPSS formation; a complex process based on the redistribution of matter due to refraction and interference of incident radiation at the interface with different refractive indexes [ 14 ].…”

“…The deposition of Cu nanowires (CuNWs) on the rippled PEN was realized by vacuum evaporation under specific conditions according to our previous study [ 24 ]. However, the copper deposition in this work was accomplished only from one side of the ripple structure.…”

“…The creation of LIPSS offers a basis for thin-film deposition with considerable surface area [ 20 , 21 ] and specific structures (nanowires) [ 22 , 23 , 24 ]. Notably, metallic materials are attractive as coatings and reinforcements for polymeric composites [ 25 , 26 ].…”

Recent Advances in the Development of Lipid-, Metal-, Carbon-, and Polymer-Based Nanomaterials for Antibacterial Applications

“…Lu et al further demonstrated that imidazole-capped chitosan–gold nanocomposites did not display hemolytic activity and significant toxicity towards L929 cell line [ 238 ]. Pryjmaková et al modified the surface of polyethylene naphthalate (PEN) by a 248 nm KrF excimer laser and subsequently, Ag and Au nanowires were incorporated onto the modified PEN surface by vacuum evaporation [ 239 ]. The resulted nanocomposites displayed antibacterial effects against Gram-negative bacteria ( E. coli ) and Gram-positive bacteria ( S. epidermidis ) via a 24-hr incubation drop plate test and were suggested as a non-toxic material by a WST-1 cytotoxicity test.…”

Spatial Period of Laser-Induced Surface Nanoripples on PET Determines Escherichia coli Repellence

“…In contrast, intrinsically bacterial-repellent surfaces can be achieved through modified surface topographies [22,[26][27][28][29], where laser-fabricated surface structures in the microand sub-micrometer range demonstrated both, increased and reduced bacterial retention [30][31][32][33][34][35][36][37]. It was suggested that the specific shape of the bacteria plays a decisive role for their adhesion as well as the depth-to-period aspect ratio of laser-generated microstructures.…”