Synthesis of biocompatible surfaces by nanotechnology methods

Abstract

The modification of the surface of low density polyethylene (LDPE) and polyurethane (PU) by means of the pulsed ion-plasma deposition of nanostructural carbon coatings at 20-60°C has been studied. The effect of this low temperature treatment on the biocompatibility of the LDPE and PU has been assessed. Optimum technological parameters for the formation of mosaic carbon nanostructures with a thickness of 0.3-15 nm and a cluster lateral size of 10-500 nm are determined. These structures give the polymer surface increased hemocompatible properties. The surface of samples was studied by methods of scanning electron microscopy, scanning probe microscopy, and Raman spectroscopy. The effect of the UV light of a krypton lamp (λ = 123.6 nm) and white synchrotron radiation on the surface of poly(methyl methacrylate) (PMMA) preliminarily treated in an oxygen containing RF discharge plasma has been investigated by varying the dura tion of exposure (from several minutes to several dozen minutes) and the residual gas pressure (2 and 100 Pa). This processing ensures the smoothing of the surface relief on micro and nanoscale levels, which can improve the biocompatibility of the modified PMMA film surface. The principles of a two stage technology for rendering the titanium (implant) surface biocompatible are developed. This technology consists of the chemical pretreatment of the surface for creating a microrelief (2-3 μm roughness), followed by the deposi tion of a titanium oxide film with controlled composition (TiO 2) and thickness (10-60 nm). The influence of the mechanisms and technological parameters of the oxide film deposition on its composition, structure, uni formity (conformal coating of involved shapes), and biocompatibility of the modified surface have been stud ied.

The Fracture of Plasma-Treated Polyurethane Surface under Fatigue Loading

“…Detailed analysis of structural-mechanical properties of the treated surfaces (roughness, fractal and wave properties, elastic modulus) and the cross-sections of the modified layer are given in the work [19]. In particular, the elastic modulus of the surface, determined by the AFM nanoindentation, increases with the plasma energy and fluence and was 20 MPa for the untreated PU, 125 MPa (PIII 1-16), 254 MPa (1-17) and 1900 MPa (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17).…”

“…Increase in the ion energy and reduction of the fluence can facilitate the development of coatings with higher fracture resistance. Another possible direction is the design of discontinuous cluster-like coatings [7], which could be more stable to the external loading.…”

“…In particular, surface energy, i.e., wettability, changes significantly, which affects the interaction with biological objects [4]: an increase of surface energy decreases the number of platelets adsorbed onto the surface [5,6]. Certain treatment regimens allow creating discontinuous cluster-like carbon coatings [7] with selective adsorption of blood proteins. As a result of ion-plasma implantation free radicals appear in the treated surface layer [8], some authors suppose that it makes the surface more favorable for the proteins [9].…”

Effect of polyvinyl alcohol adsorption on the mixed alumina–silica–titania suspension stability

“…There are numerous methods of surface modification, which may lead to changes in various characteristics of solid surface (e.g. charge, roughness, reactivity, surface energy [1][2]). Furthermore, these methods can make the solid biocompatible with a specific component of the system or the environment [3][4].…”

Matrix-Assisted Pulsed Laser Evaporation (MAPLE) technique for deposition of hybrid nanostructures

“…The modification can be done by different methods to alter a wide range of characteristics of the surface, such as: roughness [2], hydrophilicity [3], surface charge [4], surface energy, biocompatibility [5] and reactivity [6].…”