CNR Institute of Composite and Biomedical Materials

Naples, Italy

CNR Institute of Composite and Biomedical Materials

Naples, Italy
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Ronca A.,CNR Institute of Composite and Biomedical Materials | Ambrosio L.,CNR Institute of Composite and Biomedical Materials | Grijpma D.W.,University of Twente | Grijpma D.W.,University of Groningen
Acta Biomaterialia | Year: 2013

The preparation of scaffolds to facilitate the replacement of damaged tissues and organs by means of tissue engineering has been much investigated. The key properties of the biomaterials used to prepare such scaffolds include biodegradability, biocompatibility and a well-defined three-dimensional 3-Dpore network structure. In this study a poly(d,l-lactide)/nanosized hydroxyapatite (PDLLA/nano-Hap) composite resin was prepared and used to fabricate composite films and computer designed porous scaffolds by micro-stereolithography, mixing varying quantities of nano-Hap powder and a liquid photoinitiator into a photo-crosslinkable PDLLA-diacrylate resin. The influence of nano-Hap on the rheological and photochemical properties of the resins was investigated, the materials being characterized with respect to their mechanical, thermal and morphological properties after post-preparation curing. In the cured composites stiffness was observed to increase with increasing concentration of nanoparticles. A computer designed construct with a pore network based on the Schwarz architecture was fabricated by stereolithography using PDLLA/nano-Hap composite resins. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Zhan Y.,University of Sichuan | Lavorgna M.,CNR Institute of Composite and Biomedical Materials | Buonocore G.,CNR Institute of Composite and Biomedical Materials | Xia H.,University of Sichuan
Journal of Materials Chemistry | Year: 2012

Vulcanized graphene/natural rubber composites with a conductive segregated network exhibiting good electrical conductivity, water vapor permeability and high mechanical strength are prepared by self-assembly in latex and static hot pressing. The composite exhibits a percolation threshold of ∼0.62 vol% and a conductivity of 0.03 S m -1 at a content of 1.78 vol%, which is ∼5 orders of magnitude higher than that of the composites made by conventional methods at the same loading fraction. © The Royal Society of Chemistry 2012.

Bartolo P.,Polytechnic Institute of Leiria | Domingos M.,Polytechnic Institute of Leiria | Gloria A.,CNR Institute of Composite and Biomedical Materials | Ciurana J.,University of Girona
CIRP Annals - Manufacturing Technology | Year: 2011

The production methodology of 3D constructs for tissue regeneration is usually a complex discontinuous process involving three different stages: (1) production of 3D matrices; (2) matrix sterilisation and cell seeding; (3) in vitro dynamic cell culture. This paper presents a novel automated bench-top manufacturing system called BioCell Printing, designed for the integrated, continuous and fully automated production and in vitro dynamic culture of tissue engineering constructs. The BioCell aims at the rapid production of tissue-engineered substitutes with low risk of contamination, increasing the chances of direct clinical application. © 2011 CIRP.

Sorrentino A.,CNR Institute of Composite and Biomedical Materials | Pantani R.,University of Salerno
Polymer Bulletin | Year: 2013

Despite the importance of the effect of pressure on the flow properties of a polymeric material, it is often overlooked also because of the difficulties involved in the experimental measurements. In this study, the effect of pressure on viscosity for an isotactic polypropylene was characterized in both a direct and an indirect method. In particular, a homemade device was adopted to obtain data of viscosity under high pressure and high shear rates. In addition, an indirect method based on the Simha-Somcynsky equation of state was adopted to obtain the dependence of free volume on temperature and pressure on the basis of experimental specific volume measurements; the Doolittle equation was then applied to verify the dependence of viscosity on free volume. The two methods provided similar results, confirming that, at least for polypropylene, the indirect method based on specific volume measurements can be used instead of the more complex direct measurement of the viscosity under pressure. © 2013 Springer-Verlag Berlin Heidelberg.

Gorrasi G.,University of Salerno | Sorrentino A.,CNR Institute of Composite and Biomedical Materials
Polymer Degradation and Stability | Year: 2013

This paper aims to study the effect of multiwall carbon nanotubes (MWCNTs) on the photo-degradation behavior of polylactic acid (PLA) composites exposed to UV-light. The MWCNT dispersion state within the PLA matrix was analyzed by electrical conductivity measurements. From gel permeation chromatography it was verified that the rate of photo-degradation of PLA/MWCNT composites is lower than that of the unfilled PLA. The surface morphology modifications induced by UV have been analyzed by optical and scanning electron microscopy. Thermal analysis revealed an increase in the polymer crystallinity and a decrease in the degradation temperature during the UV treatment. The mechanical properties (Young's modulus and tensile strength at the yield point) were significantly increased by the addition of MWCNTs. However, the tensile strength and strain to failure slightly decreased with an increase in irradiation time. This complex behavior was attributed to a molecular reorganization in the first period of photo-aging followed by a severe macromolecular chain scission. © 2013 Elsevier Ltd. All rights reserved.

Pilla P.,University of Sannio | Trono C.,CNR Institute of Applied Physics Nello Carrara | Baldini F.,CNR Institute of Applied Physics Nello Carrara | Chiavaioli F.,CNR Institute of Applied Physics Nello Carrara | And 2 more authors.
Optics Letters | Year: 2012

We report an original design approach based on the modal dispersion curves for the development of long period gratings in transition mode near the dispersion turning point exhibiting ultrahigh refractive index sensitivity. The theoretical model predicting a giant sensitivity of 9900 nm per refractive index unit in a watery environment was experimentally validated with a result of approximately 9100 nm per refractive index unit around an ambient index of 1.3469. This result places thin film coated LPGs as an alternative to other fiber-based technologies for high-performance chemical and biological sensing applications. © 2012 Optical Society of America.

Gloria A.,CNR Institute of Composite and Biomedical Materials
Journal of the Royal Society, Interface / the Royal Society | Year: 2013

In biomedicine, magnetic nanoparticles provide some attractive possibilities because they possess peculiar physical properties that permit their use in a wide range of applications. The concept of magnetic guidance basically spans from drug delivery and hyperthermia treatment of tumours, to tissue engineering, such as magneto-mechanical stimulation/activation of cell constructs and mechanosensitive ion channels, magnetic cell-seeding procedures, and controlled cell proliferation and differentiation. Accordingly, the aim of this study was to develop fully biodegradable and magnetic nanocomposite substrates for bone tissue engineering by embedding iron-doped hydroxyapatite (FeHA) nanoparticles in a poly(ε-caprolactone) (PCL) matrix. X-ray diffraction analyses enabled the demonstration that the phase composition and crystallinity of the magnetic FeHA were not affected by the process used to develop the nanocomposite substrates. The mechanical characterization performed through small punch tests has evidenced that inclusion of 10 per cent by weight of FeHA would represent an effective reinforcement. The inclusion of nanoparticles also improves the hydrophilicity of the substrates as evidenced by the lower values of water contact angle in comparison with those of neat PCL. The results from magnetic measurements confirmed the superparamagnetic character of the nanocomposite substrates, indicated by a very low coercive field, a saturation magnetization strictly proportional to the FeHA content and a strong history dependence in temperature sweeps. Regarding the biological performances, confocal laser scanning microscopy and AlamarBlue assay have provided qualitative and quantitative information on human mesenchymal stem cell adhesion and viability/proliferation, respectively, whereas the obtained ALP/DNA values have shown the ability of the nanocomposite substrates to support osteogenic differentiation.

Raucci M.G.,CNR Institute of Composite and Biomedical Materials | Guarino V.,CNR Institute of Composite and Biomedical Materials | Ambrosio L.,CNR Institute of Composite and Biomedical Materials
Composites Science and Technology | Year: 2010

This study reports the synthesis and characterization of hydroxyapatite (HA)/polycaprolactone (PCL) hybrid composite materials synthesized by sol-gel method. The fabrication of scaffolds was performed by salt-leaching technique using NaCl as porogen agent. In the first step, the physico-chemical characterization of composite material was performed to evaluate the composition and the interaction between the organic/inorganic phases. In the second step, optimized scaffolds were bioactivated on the surface. The combined effect of scaffold morphology and surface bioactivity is ideal for bone tissue engineering, supporting bone cells adhesion, proliferation and differentiation. Here, a combined strategy involving biomimetic approach, using a supersaturated Simulated Body Fluid (SBF), and salt-leaching technique has been developed to grow hydroxyapatite in composite scaffolds able to regenerate the natural bone. © 2010 Elsevier Ltd.

Pantani R.,University of Salerno | Sorrentino A.,CNR Institute of Composite and Biomedical Materials
Polymer Degradation and Stability | Year: 2013

One of the most attractive characteristics of poly(lactic acid) (PLA) is the fact that, following the international standards for polymer biodegradation, it can be potentially degraded in soil or compost. The potential of this material, however, requires additional investigations in order to understand the PLA behaviour during composting, including the main factors that affect the biodegradation phenomena. In this work, the degradation of PLA was investigated in both distilled water and controlled composting conditions at a temperature of 58 °C. PLA samples with different morphologies were prepared by injection moulding and successive annealing at high temperature. As expected, the crystallinity was found to decrease the PLA degradation rate, but it was also found that the crystallinity affects only partially the first stages of water diffusion in the polymer matrix, whereas it has a significant effect on the final swelling of the samples and on their biodegradation rate. It could therefore be concluded that the denser structure of the initially crystalline sample was more impermeable to the enzymatic attach and to oligomer diffusion. This was also testified by the fact that if the characteristic dimension of the crystalline sample is reduced, degradation rate becomes much faster and close (although still slower) to that of the amorphous sample. © 2013 Elsevier Ltd. All rights reserved.

Alvarez-Perez M.A.,CNR Institute of Composite and Biomedical Materials | Guarino V.,CNR Institute of Composite and Biomedical Materials | Cirillo V.,CNR Institute of Composite and Biomedical Materials | Ambrosio L.,CNR Institute of Composite and Biomedical Materials
Biomacromolecules | Year: 2010

The design of functionalized polymers that can elicit specific biological responses and the development of methods to fabricate new devices that incorporate biological cues are of great interest to the biomedical community. The realization of nanostructured matrices that exhibit biological properties and that comprise fibers with diameters of similar scale to those of the natural extracellular matrix (ECM) would enable the provision of tailored materials for tissue engineering. Accordingly, the goal of this work is to create a biologically active functionalized electrospun matrix capable of guiding neurite growth for the regeneration of nerve tissue. In this study, nanoscale electrospun membranes made of poly ε-caprolactone enhanced with gelatin from calf skin were investigated to validate their biological response under in vitro culture of PC-12 nerve cells. Preliminary observations from SEM studies supported by image analysis highlighted the nanoscale texture of the scaffold with fiber diameters equal to 0.548 ± 0.140 μm. In addition, contact angle measurements confirmed the hydrophilic behavior of the membranes, ascribable to the gelatin content. We demonstrate that the balance of morphological and biochemical properties improves all the fundamental biological events of nerve regeneration, enhancing cell adhesion, proliferation, and differentiation in comparison with PCL nanofibrous scaffolds, as well as supporting the neurite outgrowth. © 2010 American Chemical Society.

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