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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.

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.

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.

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.

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