RESUMO
The scientific interest in the growth of nanostructured surfaces and thin films by means of physical vapor deposition (PVD) techniques has undoubtedly increased in the last decade [...].
RESUMO
Nanostructuration and 2D patterning of thin films are common strategies to fabricate biomimetic surfaces and components for microfluidic, microelectronic or photonic applications. This work presents the fundamentals of a surface nanotechnology procedure for laterally tailoring the nanostructure and crystalline structure of thin films that are plasma deposited onto acoustically excited piezoelectric substrates. Using magnetron sputtering as plasma technique and TiO2 as case example, it is demonstrated that the deposited films depict a sub-millimetre 2D pattern that, characterized by large lateral differences in nanostructure, density (up to 50%), thickness, and physical properties between porous and dense zones, reproduces the wave features distribution of the generated acoustic waves (AW). Simulation modelling of the AW propagation and deposition experiments carried out without plasma and under alternative experimental conditions reveal that patterning is not driven by the collision of ad-species with mechanically excited lattice atoms of the substrate, but emerges from their interaction with plasma sheath ions locally accelerated by the AW-induced electrical polarization field developed at the substrate surface and growing film. The possibilities of the AW activation as a general approach for the tailored control of nanostructure, pattern size, and properties of thin films are demonstrated through the systematic variation of deposition conditions and the adjustment of AW operating parameters.
Assuntos
Nanoestruturas , Condutividade Elétrica , Eletricidade , Nanotecnologia , SomRESUMO
Based on an already tested laboratory procedure, a new magnetron sputtering methodology to simultaneously coat two-sides of large area implants (up to ~15 cm2) with Ti nanocolumns in industrial reactors has been developed. By analyzing the required growth conditions in a laboratory setup, a new geometry and methodology have been proposed and tested in a semi-industrial scale reactor. A bone plate (DePuy Synthes) and a pseudo-rectangular bone plate extracted from a patient were coated following the new methodology, obtaining that their osteoblast proliferation efficiency and antibacterial functionality were equivalent to the coatings grown in the laboratory reactor on small areas. In particular, two kinds of experiments were performed: Analysis of bacterial adhesion and biofilm formation, and osteoblasts-bacteria competitive in vitro growth scenarios. In all these cases, the coatings show an opposite behavior toward osteoblast and bacterial proliferation, demonstrating that the proposed methodology represents a valid approach for industrial production and practical application of nanostructured titanium coatings.
RESUMO
The fabrication of black-gold coatings using sputtering is reported here. Glancing angle deposition with a rotating substrate is needed to obtain vertical nanostructures. Enhanced light absorption is obtained in the samples prepared in the ballistic regime with high tilt angles. Under these conditions the diameter distribution of the nanostructures is centered at about 60 nm and the standard deviation is large enough to obtain black-metal behavior in the visible range.
RESUMO
The authors made an observational study to evaluate the efficiency of Jaloplast (hyaluronic acid AH) as treatment for skin injuries having different etiologies. The authors highlight its results regarding cicatrisation (69%) and the improvement of lesions (15.38%). Moreover 80% of lesions have cicatrized in a time less than 11 weeks, without showing any adverse effects nor secondary effects. From these observations, the authors deduce the importance of this molecule formed by glucosamine glycane (hyalyuronate) at the organic level in general and specifically in the process of cicatrisation.
Assuntos
Adjuvantes Imunológicos/uso terapêutico , Ácido Hialurônico/uso terapêutico , Pele/lesões , Humanos , Ferimentos e Lesões/tratamento farmacológicoRESUMO
The ADDERMIS protective cream has these properties: it prevents skin maceration, exercises a regenerative effect, has bacteriostatic and bactericide activity, possesses a noted anti-inflammatory effect and reduces the risk of mycotic infections. Its application is indicated for use in cases of: skin lesions, such as bed sores or leg ulcers, which require the use of a barrier product; dermatitis lesions in zones of skin folds or due to diaper use; to prevent friction zones; fragile skin; peeling, zones where cracks in the skin appear...and to use for cases of incontinence when diapers are required.
Assuntos
Antibacterianos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Dermatopatias/prevenção & controle , Idoso , Envelhecimento/fisiologia , Humanos , Dermatopatias/etiologia , Dermatopatias/fisiopatologia , Incontinência Urinária/complicaçõesRESUMO
Bacterial colonization and biofilm formation on orthopedic implants is one of the worst scenarios in orthopedic surgery, in terms of both patient prognosis and healthcare costs. Tailoring the surfaces of implants at the nanoscale to actively promote bone bonding while avoiding bacterial colonization represents an interesting challenge to achieving better clinical outcomes. Herein, a Ti6Al4V alloy of medical grade has been coated with Ti nanostructures employing the glancing angle deposition technique by magnetron sputtering. The resulting surfaces have a high density of nanocolumnar structures, which exhibit strongly impaired bacterial adhesion that inhibits biofilm formation, while osteoblasts exhibit good cell response with similar behavior to the initial substrates. These results are discussed on the basis of a "lotus leaf effect" induced by the surface nanostructures and the different sizes and biological characteristics of osteoblasts and Staphylococcus aureus.