Recubrimientos protectores y bioactivos por sol-gel sobre aleaciones para uso clínico y odontológico

La utilización de metales como implantes biomédicos se basa fundamentalmente en las solicitaciones mecánicas extremas a las que éstos están sometidos en servicio. Su uso está a su vez condicionado por la agresividad del medio fisiológico y puede originar la liberación de productos de degradación y/o desgaste no deseados en el organismo combinado con el hecho que estos materiales son incapaces de generar una unión natural con el tejido vivo sin necesidad de fijación externa y/o cementación. En este trabajo se propone la utilización de un recubrimiento base sílice híbrida orgánico-inorgánico, con el agregado de partículas bioactivas, para aumentar la resistencia a la corrosión de la prótesis y lograr la generación de hueso neoformado sobre la misma. Se presentan ensayos in vitro e in vivo para explicar este comportamiento.Fil: Ballarre, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Protective and functional coatings on surgical grade metals: The importance of their mechanical properties

El aumento de la calidad de vida ha logrado el aumento de la longevidad de la población. Es por ello que muchas prestaciones médicas como los implantes intracorpóreos deben ajustarse a las necesidades: mejorar su performance, acortar los tiempos de tratamiento, evitar la degradación (en caso de implantes permanentes) y, por sobre todo, mejorar la oseointegración temprana. Para tanto implantes permanentes (prótesis de cadera, rodilla, codo) como temporarios (clavos y placas de fijación, tutores), se requiere que la interfase entre el implante y el hueso preexistente se genere rápidamente y sea estable. La modificación superficial de prótesis metálicas mediante recubrimientos de diferente tipo ayuda a mitigar problemas de corrosión y puede aumentar la bioactividad de la superficie, así como tener efectos antibacteriales por ejemplo. Pero la resistencia mecánica, al rayado y sobre todo la adherencia de dichos recubrimientos es clave para el éxito del implante, y es un factor que muchas veces no es tomado en cuenta. En este trabajo se presentan diferentes tipos de recubrimientos híbridos organico-inorgánicos y biopoliméricos, depositados por diferentes técnicas, así como los diferentes métodos de caracterización mecánica de películas delgadas, que ayudan a describir el comportamiento elasto-plástico y adhesivo de estas películas. Con el cuadro global de comportamiento in vitro, celular y de propiedades mecánicas de los implantes recubiertos, se podría asegurar el éxito in vivo de los dispositivos.The increase in the life quality has led to an increase in the longevity of the population. This is why many medical devices such as intracorporeal implants must adjust to new needs: improve their performance, shorten treatment times, avoid degradation (in the case of permanent implants) and, above all, improve early osseointegration. For both, permanent implants (hip, knee, elbow prostheses) and temporary implants (nails and fixation plates, tutors), the fast and stable generation of an interface between the implant and the pre-existing bone is required. Surface modification of metallic prostheses by means of different types of coatings helps to mitigate corrosion problems and can increase the bioactivity of the surface, as well as having antibacterial effects, for example. But the mechanical resistance, scratch resistance and, above all, the adherence of these coatings is a key issue for the success of the implant, and this factor is often not taken into account. In this work different types of hybrid organic-inorganic and biopolymer coatings, deposited by different techniques, as well as different methods of mechanical characterization of thin films, which help to describe the elasto-plastic and adhesive behaviour of these films are presented. With the overall picture of in vitro, cellular and mechanical properties of the coated implants, the in vivo success of the devices could be ensured.Fil: Ballarre, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Processing of microCT implant-bone systems images using Fuzzy Mathematical Morphology

The relationship between a metallic implant and the existing bone in a surgical permanent prosthesis is of great importance since the fixation and osseointegration of the system leads to the failure or success of the surgery. Micro Computed Tomography is atechnique that helps to visualize the structure of the bone. In this study, the microCT is used to analyze implant-bone systems images. However, one of the problems presented in the reconstruction of these images is the effect of the iron based implants, with a halo or fluorescence scattering distorting the micro CT image and leading to bad 3D reconstructions.In this work we introduce an automatic method for eliminate the effect of AISI 316L iron materials in the implant-b one system based on the application of Compensatory Fuzzy Mathematical Morphology for future investigate about the structural and mechanical properties of bone and cancellous materials.Fil: Bouchet, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata; ArgentinaFil: Colabella, Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Omar, Sheila Ayelén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Ballarre, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Pastore, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata; Argentin

Can anodised zirconium implants stimulate bone formation? Preliminary study in rat model

Mechanical properties and good biocompatibility of zirconium and some of its alloys focus these materials as good candidates for biomedical applications. The attractive in vivo performance of zirconium is mainly due to the presence of a protective oxide layer. In this preliminary study, surface modification of pure zirconium was made by anodisation in acidic media at low potentials, enhancing the barrier protection given by the oxides and the osseointegration. Electrochemical and SEM (scanning electron microscopy) assays were done in commercially pure zirconium cylinders and two surface conditions were compared: pure and zirconium anodised at 30V. The in vivo assays were held in a tibia rat model. The histological features and fluorochrome labelling changes of newly bone formed around implants were evaluated on the non-decalcified sections 63 days after surgery. Electrochemical and SEM assays showed that anodisation treatment would increased the barrier effect over the material and the in vivo assays showed a continuous newly bone formation around the implant with a different amount of osteocytes in their lacunaes depending the region. There was no significant change in bone thickness around both kinds of implants but conversely a significant increase in the mineralization apposition rate was determined for the anodised condition suggesting that anodisation treatment would stimulate and assist to the osseointegration process. We conclude that anodisation treatment at 30 V can stimulate the implant fixation in a rat model and this study would propose the study of zirconium as candidate material for permanent implant.Fil: Katunar, Maria Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Gomez Sanchez, Andrea Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Ballarre, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Baca, Matías. Hospital Interzonal General de Agudos ‘‘Oscar Alende’’. Mar del Plata; ArgentinaFil: Vottola, Carlos. Hospital Interzonal General de Agudos ‘‘Oscar Alende’’; ArgentinaFil: Orellano, Juan C.. Hospital Interzonal General de Agudos ‘‘Oscar Alende’’. Mar del Plata; ArgentinaFil: Schell, Hanna. Universitatsmedizin Berlin; AlemaniaFil: Duffo, Gustavo Sergio. Comision Nacional de Energia Atomica. Gerencia D/area de Energia Nuclear. Unidad de Actividad de Materiales (cac); Argentina. Universidad Nacional de San Martín; ArgentinaFil: Cere, Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentin

Sol-gel coatings for protection and biofunctionalization of stainless-steel prosthetic intracorporeal devices in Latin-America

Latin-American researchers, collaborating with the international community, have contributed in the last decades to sol-gel knowledge related to the generation of coatings on metallic bioimplants. Sol-gel technology allows the formation of relatively thin (1–2 microns) adherent, flexible and compact coatings that can be used as protection against corrosive media and for post-functionalization. Regarding low carbon surgical grade stainless steel, the application of silica-based sol-gel coatings with different types of reinforcement and incorporating bioactive or antibacterial particles as a second phase, generates promising corrosion protection properties within physiological environments. In addition, they can prevent infections and stimulate bone formation/growth. This work explores the corrosion protection features provided by thin functionalized silica sol gel coatings to be used in orthopaedic devices.Fil: Ballarre, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Ceré, Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Frictional and adhesive behavior of organic-inorganic hybrid coatings on surgical grade stainless steel using nano-scratching technique

Because of their mechanical properties, metals are the most widely used materials as orthopaedic implants. However they cannot provide a natural bond with the mineralized bone and they also release metallic particles due to degradation or tribologic events. One way to improve the metallic implants performance is to apply protective organic-inorganic sol-gel coatings. In this work, stainless steel substrates are coated with films made by a sol-gel technique from organosilane precursors. Although mechanical properties of similar films have been studied, there is no information about adhesion, friction or deformation processes of silica-based hybrid films to stainless steel substrates. Hybrid coatings with higher amount of inorganic components (called TMH) have almost no elastic response and the debris due to chipping or delamination does not persist into the indentation trace. With the film with high content of organic compounds was found elastic recovery in early stages of loading and there is evidence of pile-up at the edges of the trace with higher load applied. After the unloading the film has a persistent deformation and is removed due to the asynchronic recovery of the film and the substrate. The combined two-film coating shows a lot of debris in the trace. This is an unusual but possible behavior of polymeric coatings and could be attributed to different recoveries between the first inorganic layer (called TEOS-MTES), the substrate and the upper TMH film. This fact produces delamination and crack formation in the TEOS-MTES coating, inducing tensile efforts, and finally the upper film is pulled-off. © 2009 Elsevier B.V. All rights reserved.Fil: Ballarre, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: López, Damián A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Cavalieri, Ana Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Nano-indentation of hybrid silica coatings on surgical grade stainless steel

Hybrid silica-based coatings with tetraethoxysilane (TEOS), methyltrietoxysilane (MTES), hydroxyethyl-methacrylate (HEMA) and methacrylopropyl-trimethoxysilane (γMPS) as precursors, were employed to improve the performance of stainless steel used as orthopaedic material. Mechanical properties of the films, such as Young's modulus and hardness, were studied using the load and depth sensing indentation technique known as nano-indentation. The elastic/plastic and creep behaviours were also analyzed. Coatings with a high proportion of organic components (HEMA, γMPS) presented a more plastic response compared to the more vitreous coatings (containing only TEOS and MTES). They also showed the lowest Young's modulus and hardness. Therefore, the more vitreous coatings presented lower creep deformation that increased with the load applied.Fil: Ballarre, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: López, Damián A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Cavalieri, Ana Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Shell strength of freshwater molluscs and its implication on preservation potential

Shell strength of the modern freshwater molluscs Heleobia parchappii, Biomphalaria peregrina, Uncancylus concentricus, Musculium argentinum, Physa acuta, Succinea meridionalis and Pomacea canaliculata was quantified through load measurements and analysed using Weibull distribution, a statistical method used for brittle materials. In this study, we defined shell strength as the maximum compressive force required to break a shell per unit of resistant area, which is known as mechanical tension or stress. Intrinsic properties of shells were also measured through mineralogical and morphological characterisation. Shells were mainly composed of aragonite and varied in size and shell thickness, being P. canaliculata (biovolume = 104 mm3) the largest and H. australis and H. parchappii (3.35 and 7.93 mm3, respectively) the smallest ones. The dominant microstructure was cross-lamellar, with layers that varied between one and four. The organic matter of the matrix varied between 1.58% and 4.24%. Shell strength differs among mollusc species. Smallest species have higher shell strength than larger ones because they have a smaller resistant area on which the load is applied, and therefore the resulting value of fracture stress increases abruptly. This may explain the dominance of H. parchappii in death and fossil assemblages from Pampa sediments.Fil: Cristini, Paula Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Frontini, Patricia Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Ballarre, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Morphological and mechanical characterization of chitosan/gelatin/silica-gentamicin/bioactive glass coatings on orthopaedic metallic implant materials

Metals are the most widely used materials for orthopedics and dentistry due to their high mechanical properties. However, for certain uses like fixation plates and screws, dental implants, and osseo-articular prosthesis, their surface characteristics such as non-toxic and non-corrosive behavior, good cell adhesion and proliferation, and resistance to bacterial biofilm formation should be accompanied with high mechanical performance. One way to improve metallic implant performance in vivo is to coat them with biopolymer or inorganic thin films. This work describes two multifunctional coating systems for orthopedic titanium and stainless steel implants. Titanium implants were coated with a system consisting of a base hybrid sol-gel layer with bioactive glass particles (applied via spraying) and a top chitosan/gelatin layer with silica-gentamicin nanoparticles (applied via electrophoretic deposition, EPD). Stainless steel implants, which are designed to be removable, were coated only with the top chitosan/gelatin/ silica-gentamicin nanoparticles layer with the aim of providing a temporal attachment to bone and to combat possible bacterial adhesion. The microstructural and mechanical characterization of the coatings was conducted by optical microscopy, transmission and scanning electron microscopy, digital image processing, as well as nanoindentation and nanoscratch tests to advance the understanding of their elastic-plastic, morphologic and adhesive behavior. The coatings were homogeneous, providing good coverage to both substrates. Their surface properties, such as roughness and wettability, indicate that they represent excellent substrates for cell attachment. Bioactive glass particles can be added to titanium implant systems as bioactive components without affecting adhesion or mechanical performance of the chitosan/gelatin/silica-gentamicin nanoparticle EPD coatings. The increase in both hardness and elastic modulus of the coated systems could be due to the presence of the silica-gentamicin nanoparticles and their compaction during the penetration of the indenter. When the samples are subjected to scratch tests, the critical load increases with the reinforcement of the coatings by the silica-gentamicin nanoparticles absorbing the applied load and maintaining the elastic properties of the coatings.Peer ReviewedPostprint (author's final draft

Hybrid organic-inorganic silica-based coatings deposited by spray technique

AISI 316L stainless steel is mainly used in biomedical applications, even though it suffers localized corrosion. Its protection can be achieved creating a barrier for ions migration. This paper presents the synthesis and deposition of sol gel coatings over AISI 316L, done by spray and dip-coating method, using tetraethoxysilane (TEOS), methyltriethoxysilane (MTES) and colloidal silica nanoparticles as precursors. Both coatings are analysed by optical microscopy, mechanical profilometry and electrochemical tests in simulated body fluid solution. The spray deposition technique is presented as a versatile way to generate thin layers enabling to coat complex geometries and being promising for industrial purposes.Fil: Omar, Sheila Ayelén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingenieria; ArgentinaFil: Pellice, Sergio Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingenieria; ArgentinaFil: Ballarre, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingenieria; ArgentinaFil: Cere, Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingenieria; Argentin