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Neural tissue engineering has recently emerged as an alternative strategy to repair nerve damage and promote nerve regeneration. It involves the fabrication of scaffolds with properties mimicking those of the natural extracellular matrix for guiding a three-dimensional (3D) neural regeneration. These engineered constructs, in addition to mechanical support, should be also capable of providing proper chemical and electrical stimuli for adhesion, migration, and proliferation of the neural cells. In this study, we developed conductive composite hydrogel films based on gelatin and carbon black (CB) as scaffolds for neural tissue engineering applications. The presented hydrogel constructs were fabricated in the form of films using the solvent casting method after dispersing several concentrations of CB in a 5 % (w/v) gelatin solution along with (3-glycidoxypropyl)trimethoxysilane (GPTMS) as the crosslinking agent at a concentration of 1.84 % (v/v). The CB concentrations of 0.3 %, 0.5 %, 0.7 %, and 0.9 % (w/w) with respect to the gelatin amount were chosen. The morphological, compositional, swelling, dissolution, electrical, mechanical, and wettability properties together were characterized as function of CB content and compared with those of pure gelatin-based hydrogel. Results demonstrated that the incorporation of different quantities of CB relatively reduced the water uptake capability of the films and increased the stability in water of the gelatin matrix. Findings from the mechanical tests revealed that composite hydrogels have a lower elastic modulus with respect to the pure gelatin matrix. Moreover, it was found that the incorporation of incremental CB concentrations kept the wettability surface property unchanged while the electrical characterization of the proposed structures showed a reduction of the electrical impedance. Overall, the study suggests that the composite structures could be used as a potential candidate for fabrication of scaffolds for neural regeneration with tunable electrical and mechanical properties by varying the CB concentration in a finite range.

Megakaryocytes (MK) in the bone marrow (BM) are immersed in a network of extracellular matrix components that regulates platelet release into the circulation. Combining biological and bioengineering approaches, we found that the activation of transient receptor potential cation channel subfamily V member 4 (TRPV4), a mechano-sensitive ion channel, is induced upon MK adhesion on softer matrices. This response promoted platelet production by triggering a cascade of events that lead to calcium influx, β1 integrin activation and internalization, and Akt phosphorylation, responses not found on stiffer matrices. Lysyl oxidase (LOX) is a physiological modulator of BM matrix stiffness via collagen crosslinking. In vivo inhibition of LOX and consequent matrix softening lead to TRPV4 activation cascade and increased platelet levels. At the same time, in vitro proplatelet formation was reduced on a recombinant enzyme-mediated stiffer collagen. These results suggest a novel mechanism by which MKs, through TRPV4, sense extracellular matrix environmental rigidity and release platelets accordingly.

The majority of strategies used in tissue engineering (TE) employ a scaffold, which is used to guide .the proliferation, the migration and the adhesione of cell in 3D to pruduce an engineered tissue. A new trend in scaffolds’s fabrication is represented by the hybrid Rapid Prototyping technologies. This is a new multimaterial and multiscale fabrication approach which combine the common RP technologies with other micro/nanofabrication techiques to fabricate scaffold that mimick the hetereogenty and hierarchical structure typical of the native extracellular matrix. In this new contest our work present: 1) an innovative device for the fabrication of multi material scaffolds based on an open source FDM 3D printer suitably modified to integrate a multi nozzle deposition tool 2) a design proposal for a multi material and multi scale machine to allow a full control over the modulation of the building materials and of the topography in a scaffold 3) and lastly a CAD workflow to guide the fabrication of RP patient specific scaffolds. Multifunctional hydrogel-based scaffold are fabricated as a demonstration of the validity of the proposed devices. Starting from a clinical case we print a patient-specific scaffold with the aim to recover bone defects at mandibular level as a validation of the proposed CAD process.

A parallel manipulator with three translational degrees of freedom for microfabrication of biomaterials was designed for a given workspace. The device was opportunely designed to mount the following biofabrication tools on its mobile platform: a pressure-driven extrusion tool, a piston-driven extrusion tool, and an electrospinning tool. Taking advantage of the modularity of the system, it was possible to combine these different techniques to obtain multimaterial and multiscale scaffolds with structural and mechanical characteristics more similar to biological tissues. In this work, hydrogel-based composite scaffolds were fabricated as a demonstration.

Tissue engineering (TE) aims at producing patient-specific biological substitutes in an attempt to repair, replace and regenerate damaged tissues or organs in order to improve the current state of clinical treatments. A three-dimensional substrate, the scaffold, is a key aspect to promote cell organization to form a tissue. Recently, rapid prototyping (RP) technologies have been successfully used to fabricate complex scaffolds, thanks to the ability to create highly reproducible architecture and compositional variation across the entire structure, due to their precise controlled computer driven fabrication. The drawback of most of the fabrication principles applied in the RP processes is the requirement of particular conditions (e.g., pressure or temperature) that limit the material choice. Natural polymers, such as collagen, have underlined their superiority for TE solutions but they are challenging to be processed with RP techniques. As alternative, scaffold made of natural biomaterial can be produced by indirect fabrication techniques, casting a biomaterial into sacrificial mold realized by RP processes. So far, the indirect rapid prototyping (iRP) has emerged in a number of different approaches with promising results. The present chapter is focused on iRP multistep methods, highlighting strength and weakness and indicating possible future perspectives.

The knowledge of lipid components of wheat finds a precious information in order to differentiate between Triticum durum (TD) and Triticum aestivum (TA). The determination of the percentages of methyl esters of the differently unsaturated fatty acids with 18-carbon atoms (C18), of sterol fraction and of the other components is of particular weight. In this paper, the classification methods of linear discriminant analysis (LDA) and quadratic discriminant analysis (QDA) were applied in order to measure the classification and prediction abilities of the determined (percentages of the) components of the lipid fraction of wheat in differentiating among species, origins, varieties and crops. By univariate feature selection method (Fisher weights (FW)) and linear discriminant analysis, it was found that the only oleate is able to distinguish between the two species with a prediction rate of 100%. Inside the species Triticum durum, it was obtained a prediction rate of 83.9% while discriminating between the different origins, a prediction rate of 82.2% while discriminating among varieties and a prediction rate of 94.3% among crop years.

Des analyses ont ete faites sur des taches de moisissure de six differents papiers datant du 16eme au 18eme siecles ainsi que sur des taches ressemblantes sur du papier moderne, obtenues par addition de gouttes d'une solution de FeCl 3 , KCl et FeCl 3 + KCl (5.10 -3 M) en quantites differentes (1, 3 et 5 μl) et apres vieillissement accelere. Les analyses portaient sur la chromaticite, la fluorescence sous l'effet de la lumiere UV, la teneur en carbonyle et l'epaisseur ; ensuite ces taches ont ete soumises a une spectroscopie IP et a une spectroscopie XRF. Le resultat observe demontre qu'il existe un rapport etroit entre l'apparition des taches de moisissure et une forte oxydation de la chaine cellulosique. Independamment du fait qu'il existe certaines differences et probablement des differences specifiques a chacune des sortes de taches de moisissure, cette forte oxydation est la seule caracteristique commune a toutes.

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The official method to determine the number of eggs present in egg-noodles is the digitonin method. By applying this method the total content of sterols is determined and expressed as total sterols. The official method is time consuming, not very accurate and its performance is very complicated. Its results are not very reliable either because the composition of the wheat is not considered. In this paper some markers are proposed to verify the correct ratio between eggs and triticum durum (TD) semolina used to prepare egg-noodles. Markers are selected ratios between sterols and FAME. The lipid extract is trans-esterified and injected into a gas chromatograph. The ratio between the areas of the selected components gives the markers. This method is proposed to substitute or alternate the official method because is more accurate and time saving.

Foxing is a complex phenomenon, not yet well understood. The term is applied to stains of reddish-brown, brown, or yellowish colour, gener¬ally of small dimensions, with sharp or irregular edges, most of which, if excited with UV light, show fluorescence. Fluorescence is also often present in areas in which the alteration is not yet visible under natural light, but which is probably in for¬mation 1?9. Its formation mechanisms have been studied since 1935, however, despite more recent intensive research since the 1980s there are still no conclusive results. Some authors found evidence of bacterial and fungal stains in some foxed areas sometimes associated with the presence of iron. We decided to analyse some foxed stains present on naturally aged papers from the 16th to 18th centuries, trying to find a common trend for a better comprehension of the foxing phenomenon and also for finding restoring procedures and methods. We applied non-destructive techniques and, when it was possible, destructive techniques to carry out a more complete analyses. Some samples were treated with borane tert-butylamine complex, a reducing compound 10, to test its effectiveness in reducing oxidised functional groups present in the foxed areas.In the present work we will focus our attention on the XRF results obtained from ancient papers.