Bioactive zinc-doped sol-gel coating modulates protein adsorption patterns and in vitro cell responses.

Zinc is an essential element with an important role in stimulating the osteogenesis and mineralization and suppressing osteoclast differentiation. In this study, new bioactive ZnCl2-doped sol-gel materials were designed to be applied as coatings onto titanium. The biomaterials were physicochemically characterized and the cellular responses evaluated in vitro using MC3T3-E1 osteoblasts and RAW264.7 macrophages. The effect of Zn on the adsorption of human serum proteins onto the material surface was evaluated through nLC-MS/MS. The incorporation of Zn did not affect the crosslinking of the sol-gel network. A controlled Zn2+ release was obtained, reaching values below 10 ppm after 21 days. The materials were no cytotoxic and lead to increased gene expression of ALP, TGF-ß, and RUNX2 in the osteoblasts. In macrophages, an increase of IL-1ß, TGF-ß, and IL-4 gene expression was accompanied by a reduced TNF-α liberation. Proteomic results showed changes in the adsorption patterns of proteins associated with immunological, coagulative, and regenerative functions, in a Zn dose-dependent manner. The variations in protein adsorption might lead to the downregulation of the NF-κB pathway, thus explain the observed biological effects of Zn incorporation into biomaterials. Overall, these coatings demonstrated their potential to promote bone tissue regeneration.

Complement proteins regulating macrophage polarisation on biomaterials.

One of the events occurring when a biomaterial is implanted in an host is the protein deposition onto its surface, which might regulate cell responses. When a biomaterial displays a compromised biocompatibility, distinct complement pathways can be activated to produce a foreign body reaction. In this article, we have designed different types of biomaterial surfaces to study the inflammation process. Here, we used different concentrations of (3-glycidoxypropyl)-trimethoxysilane (GPTMS), an organically-modified alkoxysilane as a precursor for the synthesis of various types of sol-gel materials functionalizing coatings for titanium implants to regulate biological responses. Our results showed that greater GPTMS surface concentrations induced greater secretion of TNF-α and IL-10 on RAW 264.7 macrophages. When implanted into rabbit tibia, osseointegration decreased with higher GPTMS concentrations. Interestingly, higher deposition of complement-related proteins C-reactive protein (CRP) and ficolin-2 (FCN2), two main activators of distinct complement pathways, was observed. Taking all together, inflammatory potential increase seems to be GPTMS concentration-dependent. Our results show that a greater adsorption of complement proteins can condition macrophage polarization.

Proteomic analysis of calcium-enriched sol-gel biomaterials.

Calcium is an element widely used in the development of biomaterials for bone tissue engineering as it plays important roles in bone metabolism and blood coagulation. The Ca ions can condition the microenvironment at the tissue-material interface, affecting the protein deposition process and cell responses. The aim of this study was to analyze the changes in the patterns of protein adsorption on the silica hybrid biomaterials supplemented with different amounts of CaCl2, which can function as release vehicles. This characterization was carried out by incubating the Ca-biomaterials with human serum. LC-MS/MS analysis was used to characterize the adsorbed protein layers and compile a list of proteins whose affinity for the surfaces might depend on the CaCl2 content. The attachment of pro- and anti-clotting proteins, such as THRB, ANT3, and PROC, increased significantly on the Ca-materials. Similarly, VTNC and APOE, proteins directly involved on osteogenic processes, attached preferentially to these surfaces. To assess correlations with the proteomic data, these formulations were tested in vitro regarding their osteogenic and inflammatory potential, employing MC3T3-E1 and RAW 264.7 cell lines, respectively. The results confirmed a Ca dose-dependent osteogenic and inflammatory behavior of the materials employed, in accordance with the protein attachment patterns.

The effect of strontium incorporation into sol-gel biomaterials on their protein adsorption and cell interactions.

It is known strontium can both inhibit the osteoclast formation and stimulate the osteoblast maturation, so biomaterials containing this element can favour bone structure stabilisation. The addition of Sr to biomaterials could affect their interactions with proteins and cells. Here, a silica-hybrid sol-gel network doped with different amounts of SrCl2 and applied as coatings on titanium discs was examined. in vitro analysis was performed to determine the potential effect of Sr in the coatings, showing enhanced gene expression of osteogenic markers (alkaline phosphatase and transforming growth factor-ß) in MC3T3-E1 incubated with Sr-doped biomaterials. The examination of inflammatory markers (tumour necrosis factor-α and interleukin 10) in RAW 264.7 macrophages revealed an anti-inflammatory potential of these materials. Proteins adsorbed onto the coatings incubated with human serum (3 h at 37 °C) were also analysed; mass spectrometry was used to characterise the proteins adhering to materials with different Sr content. Adding Sr to the coatings increased their affinity to APOE and VTNC proteins (associated with anti-inflammatory and osteogenic functions). Moreover, the proteins involved in coagulation processes, such as prothrombin, were more abundant on the coatings containing Sr than on the base sol-gel surfaces. Correlations between gene expression and proteomic results were also examined.

Osseointegration mechanisms: a proteomic approach.

The prime objectives in the development of biomaterials for dental applications are to improve the quality of osseointegration and to short the time needed to achieve it. Design of implants nowadays involves changes in the surface characteristics to obtain a good cellular response. Incorporating osteoinductive elements is one way to achieve the best regeneration possible post-implantation. This study examined the osteointegrative potential of two distinct biomaterials: sandblasted acid-etched titanium and a silica sol-gel hybrid coating, 70% MTMOS-30% TEOS. In vitro, in vivo, and proteomic characterisations of the two materials were conducted. Enhanced expression levels of ALP and IL-6 in the MC3T3-E1 cells cultured with coated discs, suggest that growing cells on such surfaces may increase mineralisation levels. 70M30T-coated implants showed improved bone growth in vivo compared to uncoated titanium. Complete osseointegration was achieved on both. However, coated implants displayed osteoinductive properties, while uncoated implants demonstrated osteoconductive characteristics. Coagulation-related proteins attached predominantly to SAE-Ti surface. Surface properties of the material might drive the regenerative process of the affected tissue. Analysis of the proteins on the coated dental implant showed that few proteins specifically attached to its surface, possibly indicating that its osteoinductive properties depend on the silicon delivery from the implant.

Scaffolds of Hyaluronic Acid-Poly(Ethyl Acrylate) Interpenetrating Networks: Characterization and In Vitro Studies.

Hyaluronic acid (HA) provides many advantages to regenerative implants through its bioactive properties, but it also has many limitations as a biomaterial if it is not chemically modified. In order to overcome some of these limitations, HA has been combined with poly(ethyl acrylate) in the form of interpenetrating polymeric networks (IPNs), in which the HA network is crosslinked with divinyl sulfone. Scaffolds of this IPN have been produced through a template-leaching methodology, and their properties have been compared with those of single-network scaffolds made of either PEA or crosslinked HA. A fibroblast cell line has been used to assess the in vitro performance of the scaffolds, revealing good cell response and a differentiated behavior on the IPN surface when compared to the individual polymers. Altogether, the results confirm that this type of material offers an interesting microenvironment for cells, which can be further improved toward its potential use in medical implants.

Influence of scaffold morphology on co-cultures of human endothelial and adipose tissue-derived stem cells.

The interior of tissue engineering scaffolds must be vascularizable and allow adequate nutrients perfusion in order to ensure the viability of the cells colonizing them. The promotion of rapid vascularization of scaffolds is critical for thick artificial constructs. In the present study co-cultures of human endothelial and adipose tissue-derived stem cells have been performed in poly(ethyl acrylate) scaffolds with two different pore structures: grid-like (PEA-o) or sponge-like (PEA-s), in combination with a self-assembling peptide gel filling the pores, which aims to mimic the physiological niche. After 2 and 7 culture days, cell adhesion, proliferation and migration, the expression of cell surface markers like CD31 and CD90 and the release of VEGF were assessed by means of immunocytochemistry, scanning electronic microscopy, flow cytometry and ELISA analyses. The study demonstrated that PEA-s scaffolds promoted greater cell organization into tubular-like structures than PEA-o scaffolds, and this was enhanced by the presence of the peptide gel. Paracrine signaling from adipose cells significantly improved endothelial cell viability, proving the advantageous combination of this system for obtaining easily vascularizable tissue engineered grafts. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1523-1533, 2016.

Hydrophilic surface modification of acrylate-based biomaterials.

Acrylic polymers have proved to be excellent with regard to cell adhesion, colonization and survival, in vitro and in vivo. Highly ordered and regular pore structures thereof can be produced with the help of polyamide templates, which are removed with nitric acid. This treatment converts a fraction of the ethyl acrylate side groups into acrylic acid, turning poly(ethyl acrylate) scaffolds into a more hydrophilic and pH-sensitive substrate, while its good biological performance remains intact. To quantify the extent of such a modification, and be able to characterize the degree of hydrophilicity of poly(ethyl acrylate), poly(ethyl acrylate) was treated with acid for different times (four, nine and 17 days), and compared with poly(acrylic acid) and a 90/10%wt. EA/AAc copolymer (P(EA-co-AAc)). The biological performance was also assessed for samples immersed in acid up to four days and the copolymer, and it was found that the incorporation of acidic units on the material surface was not prejudicial for cells. This surface modification of 3D porous hydrophobic scaffolds makes easier the wetting with culture medium and aqueous solutions in general, and thus represents an advantage in the manageability of the scaffolds.

Schwann-cell cylinders grown inside hyaluronic-acid tubular scaffolds with gradient porosity.

Cell transplantation therapies in the nervous system are frequently hampered by glial scarring and cell drain from the damaged site, among others. To improve this situation, new biomaterials may be of help. Here, novel single-channel tubular conduits based on hyaluronic acid (HA) with and without poly-l-lactide acid fibers in their lumen were fabricated. Rat Schwann cells were seeded within the conduits and cultured for 10days. The conduits possessed a three-layered porous structure that impeded the leakage of the cells seeded in their interior and made them impervious to cell invasion from the exterior, while allowing free transport of nutrients and other molecules needed for cell survival. The channel's surface acted as a template for the formation of a cylindrical sheath-like tapestry of Schwann cells continuously spanning the whole length of the lumen. Schwann-cell tubes having a diameter of around 0.5mm and variable lengths can thus be generated. This structure is not found in nature and represents a truly engineered tissue, the outcome of the specific cell-material interactions. The conduits might be useful to sustain and protect cells for transplantation, and the biohybrids here described, together with neuronal precursors, might be of help in building bridges across significant distances in the central and peripheral nervous system. STATEMENT OF SIGNIFICANCE: The paper entitled "Schwann-cell cylinders grown inside hyaluronic-acid tubular scaffolds with gradient porosity" reports on the development of a novel tubular scaffold and on how this scaffold acts on Schwann cells seeded in its interior as a template to produce macroscopic hollow continuous cylinders of tightly joined Schwann cells. This cellular structure is not found in nature and represents a truly engineered novel tissue, which obtains as a consequence of the specific cell-material interactions within the scaffold.

New semi-biodegradable materials from semi-interpenetrated networks of poly(ϵ-caprolactone) and poly(ethyl acrylate).

Semi-degradable materials may have many applications. Here poly(ethyl acrylate) and poly(ϵ-caprolactone) were combined as semi-interpenetrated networks, and thoroughly characterized in terms of final composition, interactions between components, wettability, and mechanical properties. PCL modulates the mechanical properties of the PEA elastomeric network. Cultures of fibroblasts and adipose-tissue derived stem cells showed excellent biological performance of the materials. The results are relevant for applications seeking materials leaving a permanent supporting skeleton after the partial degradation, as in patches for cardiac regeneration or in abdominal wall meshes.

Grid polymeric scaffolds with polypeptide gel filling as patches for infarcted tissue regeneration.

Scaffolds of poly(ethyl acrylate) (PEA) with interconnected cylindrical orthogonal pores filled with a self-assembling peptide (SAP) gel are here proposed as patches for infarcted tissue regeneration. These combined systems aim to support cell therapy and meet further requirements posed by the application: the three-dimensional architecture of the elastomeric scaffold is expected to lodge the cells of interest in the damaged zone avoiding their death or migration, and at the same time conduct cell behavior and give mechanical support if necessary; the ECM-like polypeptide gel provides a cell-friendly aqueous microenvironment, facilitates diffusion of nutrients and cell wastes and is expected to improve the distribution and viability of the seeded cells within the pores and stimulate angiogenesis.

Combining self-assembling peptide gels with three-dimensional elastomer scaffolds.

Some of the problems raised by the combination of porous scaffolds and self-assembling peptide (SAP) gels as constructs for tissue engineering applications are addressed for the first time. Scaffolds of poly(ethyl acrylate) and the SAP gel RAD16-I were employed. The in situ gelation of the SAP gel inside the pores of the scaffolds was studied. The scaffold-cum-gel constructs were characterized morphologically, physicochemically and mechanically. The possibility of incorporating an active molecule (bovine serum albumin, taken here as a model molecule for others) in the gel within the scaffold's pores was assessed, and the kinetics of its release in phosphate-buffered saline was followed. Cell seeding and colonization of these constructs were preliminarily studied with L929 fibroblasts and subsequently checked with sheep adipose-tissue-derived stem cells intended for further preclinical studies. Static (conventional) and dynamically assisted seedings were compared for bare scaffolds and the scaffold-cum-gel constructs. The SAP gel inside the pores of the scaffold significantly improved the uniformity and density of cell colonization of the three-dimensional (3-D) structure. These constructs could be of use in different advanced tissue engineering applications, where, apart from a cell-friendly extracellular matrix -like aqueous environment, a larger-scale 3-D structure able to keep the cells in a specific place, give mechanical support and/or conduct spatially the tissue growth could be required.

Electrospun adherent-antiadherent bilayered membranes based on cross-linked hyaluronic acid for advanced tissue engineering applications.

A procedure to obtain electrospun mats of hyaluronic acid (HA) stable in aqueous media in one single step has been developed. It consists in combining an HA solution with a divinyl sulfone one as cross-linker in a three-way valve to immediately electroblow their mixture. Membranes obtained with this method, after sterilization and conditioning, are ready to use in cell culture without need of any additional post-treatment. HA nanofibers are deposited onto previously electrospun poly(l-lactic acid) (PLLA) mats in order to obtain stably joined bilayered membranes with an adherent face and the opposite face non-adherent, despite their different hydrophilicity and mechanical properties. These bilayered HA/PLLA membranes may be of use, for example, in applications seeking to transplant cells on a tissue surface and keep them protected from the environment: the PLLA nanofiber face is cell friendly and promotes cell attachment and spreading and can thus be used as a cell supply vehicle, while the HA face hinders cell adhesion and thus may prevent post-surgical adherences, a major issue in many surgeries.

Evaluación de un sistema de telemedicina para una consulta dealta resolución en cirugía mayor ambulatoria / No disponible

Objetivos: El propósito del presente trabajo es, en primer lugar, el de evaluar la capacidad diagnóstica de un sistema de telemedicina, basado en una herramienta de video conferencia, utilizado para optimizar la Consulta de Alta Resolución de la Unidad de Cirugía Mayor Ambulatoria del Hospital Clínico San Carlos de Madrid. Y en segundo lugar, el de conocer la opinión de los pacientes sobre este sistema de telemedicina. Material y métodos: Se ha utilizado un sistema de video conferencia constituido por dos terminales conectadas a través de la LAN del hospital mediante el kit Intel® Proshare® Video System 500. La terminal del paciente posee una cámara con zoom óptico, auto foco y control a distancia desde la terminal del médico. En total se han incluido 104 pacientes (73% varones) con una edad media de 51 años (22-80 años) correspondientes a los siguientes procesos: hernias de la pared abdominal, 63,5%; lipomas superficiales, 21,15%; sinus pilonidal, 10,6%; e hidrosadenitis, 4,8%. Se establece la concordancia diagnóstica entre la teleconsulta y la consulta presencial. Para conocer la opinión de los pacientes sobre este sistema de telemedicina, se ha elaborado una encuesta con 10 preguntas: 9 de tipo cerrado y una abierta. De las 9 preguntas cerradas, 7 son dicotómicas puras y 2 ofrecen 4 opciones de respuesta que son mutuamente excluyentes. Resultados: La concordancia de los datos obtenidos en las teleconsultas y en las consultas presenciales, de las diferentes patologías incluidas en el estudio, ha sido la (..) (AU)

Objectives: The intention of the present study is, first of all, to evaluate the diagnostic capacity of a telemedicine system based on a tool of video conference, used to optimize the High Resolution Consultation of the Unit of Ambulatory Surgery in the “San Carlos” Clinical Hospital of Madrid. And secondly, to know the opinion of the patients using this telemedicine system. Material and methods: The video conference system used is formed by two terminals connected through the LAN of the hospitalby means of A kit Intel® Proshare® Video System 500. The terminal for the patient has a camera with optical zoom lens, auto-focus and remote control from the doctor’s terminal. 104 have been included patients in this study (73% men) with an averageage of 51 years (22-80 years) corresponding to the following processes: hernias of the abdominal wall, 63.5%; superficial lipomas,21.15%; pilonidal sinus, 10.6%; and hidrosadenitis, 4.8%. Results received from the teleconsultation are matched to those obtained at the in person consultation. In order to know the opinion of the patients about this telemedicine system, a survey with 10 questions was elaborated: 9 were the closed type and one open question. Of the 9 closed questions, 7 are purely yes/no and2 offer 4 answer options that are mutually excluding. Results: The data collected in the teleconsultations matched those of the in-person consultations, regarding the different pathologies included in the study, as follows: inguinal hernia, positive (..) (AU)

Uso de biomateriales con fines neurorregenerativos. Aplicación en modelo experimental de traumatismo craneoencefálico / Use of biomaterials in neural regeneration. Application in an experimental model of head injury

Objetivos: Evaluar el rendimiento de los biomateriales poliméricos basados en ácido hialurónico y su utilidad en el Sistema Nervioso Central, sirviendo como soporte, para la supervivencia y diferenciación celular. Material y Metodos: Con el fin de evaluar la viabilidad de los soportes poliméricos y acanalados, se realizaron experimetos in vitro e in vivo mediante el implante en corteza cerebral de ratas Wistar. Mediante técnicas inmunocitoquímicas e histológicas se procedió al análisis de la viabilidad de los soportes. Resultados: Tras el cultivo pudimos constatar la viabilidad celular sobre los biomateriales, asi como su potencial utilidad para la regeneración in vivo de estructuras vasculares y neurales. Conclusiones: La posibilidad de regenerar estructuras vasculares y neurales a través del implante de biomateriales basados en ácido hialurónico, constituye un avance en la utilización de biomateriales en el Sistema Nervioso Central (AU)

Objetives: To evaluate the performance of polymeric biomaterials based on hyaluronic acid and their usefulness in the central nervous system as support for cell differentiation and survival. Material and methods: With the purpose of assessing the viability of polymeric cannulated scaffolds, in vitro and in vivo experiments were made involving implantation in the Wistar rate brain cortex. Immunocytochemical and histological techniques were used to analyze scaffold viability. Results: Following culture, cell viability on the biomaterials was confirmed, together with the potential usefulness of the latter for the in vivo regeneration of vascular and neural structures. Conclusions: The possibility of regenerating vascular and neural structures through the implantation of biomaterials based on hyaluronic acid constitutes an advance in the use of biomaterials in the central nervous system (AU)

Desarrollo de un sistema de telemedicina mediante videoconferencia para la consulta de alta resolución en cirugía mayor ambulatoria / No disponible

los requisitos necesarios para implementar un sistema de telemedicina basado en una herramienta de videoconferencia, para optimizarla Consulta de Alta Resolución (CAR) en una Unidad de Cirugía Mayor Ambulatoria (UCMA).Material y métodos: Se ha utilizado un sistema de videoconferencia constituido por dos terminales conectadas a través de la LAN del hospital mediante el kit Intel® Proshare® Video System500. La terminal del paciente posee una cámara con zoom óptico, autofoco y control a distancia desde la terminal del médico. Se han realizado pruebas de conectividad, de estabilidad y de calidad de audio y video, en 30 pacientes seleccionados con los mismos criterios de inclusión utilizados para la CAR de la UCMA del H. Clínico S. Carlos de Madrid. Las patologías incluidas han sido:hernia inguinal 46,7%; hernia umbilical 13,3%; sinus pilonidal16,7%; hidrosadenitis axilar 10% y lipoma 13,3%. Se ha valorado la concordancia entre las observaciones presenciales y las obtenidas mediante videoconferencia, tanto en la anamnesis como en las imágenes de las patologías de estos pacientes. Se ha establecido el perfil más adecuado de los pacientes y analizado su opinión sobre este sistema de telemedicina. Resultados: Las anamnesis y las imágenes obtenidas mediante videoconferencia son coincidentes con las obtenidas en observación presencial. La concordancia diagnóstica ha sido del 100%en los casos de hernia umbilical, sinus pilonidal, hidrosadenitis axilary lipomas. En los casos de hernia inguinal, la concordancia diagnóstica ha sido del 43%. En el 21% de los casos, la anamnesis mediante videoconferencia ha sugerido el diagnóstico correcto, pero las imágenes ofrecían dudas para confirmarlo. En el 36% delos casos, las imágenes no permitían (..) (AU)

Objective: The purpose of this study is to check and to evaluate the necessary requirements to implement a videoconference based telemedicine system, to optimize the High Resolution Outpatient Surgery (HROS) in an Ambulatory Surgery Unit (ASU).Material and methods: A videoconference system using two terminals connected through the LAN of the hospital by means ofthe kit Intel® Proshare® Video System 500 was used. The patient’s terminal has a camera with an optic zoom, auto focus and control at a distance from the doctor's terminal. Connectivity and stability tests and an analysis of audio and video quality were performed, in 30 patients selected following the same inclusion criteria used in the HROS of the ASU at the St. Carlos Clinical Hospitalin Madrid. The various pathologies included were: inguinal(46.7%) and umbilical (13.3%) hernias; pilonidal sinus 16.7%; axillary hidradenitis 10% and lipoma 13.3%. We compared both anamnesis and the images obtained in the surgery and through videoconference to see if they coincided. We have now decided which patient profile is most successful and we have analyzed their opinions regarding this telemedicine system. Results: The anamnesis and the images obtained in these patients by videoconference, coincide with those obtained by face to face observation. Diagnosis was a 100% correct in cases of umbilica lhernias, pilonidal sinus, axillary hidradenitis and lipomas. In the case of inguinal hernias, diagnosis coincided in 43%. In 21%o f the cases, the history taken through video-conference suggested the correct diagnosis, but the images were not sufficient to confirm the diagnosis. Generally the best profile is a patient (..) (AU)

La cirugía mayor ambulatoria y los retos actuales del Sistema Sanitario / No disponible

No disponible