Stranieri. Itinerari di vita studentesca tra XIII e XVIII secolo.

Questo volume osserva l’università come punto di incontro tra uomini di età diverse e di origini geografiche molteplici. Ciò vale in particolare modo per l’Ateneo patavino, che deve le sue origini proprio a una migrazione di scolari. Un evento circoscritto, che tuttavia rientra nel fenomeno più ampio e diffuso della mobilità accademica che caratterizza il medioevo e la prima età moderna. Nel corso del medioevo – con un’accelerazione notevole a partire dal XII secolo – maestri e scolari furono indotti a muoversi verso i centri del sapere – monasteri, scuole, cattedrali, conventi, università – alla ricerca degli ambienti più stimolanti dal punto di vista intellettuale e delle condizioni che meglio garantissero l’apprendimento, quali ad esempio la presenza di ricche biblioteche o le lezioni dei docenti più illustri. I cosiddetti clerici vagantes costituivano un gruppo estremamente eterogeneo dal punto di vista geografico e sociale, provenendo da tutto il continente europeo. Una mobilità che ha continuato a marcare la vita accademica, in particolare di Padova, la cui comunità studentesca si è da sempre arricchita di un’ampia componente proveniente dall’esterno della città: dall’impero tedesco alla Francia, dalla Polonia alla Grecia, ma anche dall’Italia meridionale. I dati utilizzati nel volume provengono da un database che raccoglie più di 70 000 laureati a Padova, costruito per l’ottocentenario dell’Università e realizzato anche grazie al lavoro di molti studenti, che vi hanno dedicato il loro impegno e le loro energie

A Protocol to Enhance INS1E and MIN6 FunctionalityThe Use of Theophylline

In vitro research in the field of type I diabetes is frequently limited by the availability of a functional model for islets of Langerhans. This method shows that by the addition of theophylline to the glucose buffers, mouse insulinoma MIN6 and rat insulinoma INS1E pseudo-islets can serve as a model for islets of Langerhans for in vitro research. The effect of theophylline is dose- and cell line-dependent, resulting in a minimal stimulation index of five followed by a rapid return to baseline insulin secretion by reducing glucose concentrations after a first high glucose stimulation. This protocol solves issues concerning in vitro research for type I diabetes as donors and the availability of primary islets of Langerhans are limited. To avoid the limitations of using human donor material, cell lines represent a valid alternative. Many different cell lines have been reported, but the lack of reproducible responsiveness to glucose stimulation remains a challenge

Layered PEGDA hydrogel for islet of Langerhans encapsulation and improvement of vascularization

Abstract: Islets of Langerhans need to maintain their round morphology and to be fast revascularized after transplantation to preserve functional insulin secretion in response to glucose stimulation. For this purpose, a non-cell-adhesive environment is preferable for their embedding. Conversely, nutrient and oxygen supply to islets is guaranteed by capillary ingrowth within the construct and this can only be achieved in a matrix that provides adhesion cues for cells. In this study, two different approaches are explored, which are both based on a layered architecture, in order to combine these two opposite requirements. A non-adhesive islet encapsulation layer is based on polyethyleneglycole diacrylate (PEGDA). This first layer is combined with a second hydrogel based on thiolated-gelatin, thiolated-heparin and thiolated-hyaluronic acid providing cues for endothelial cell adhesion and acting as a growth factor releasing matrix. In an alternative approach, a conformal PEGDA coating is covalently applied on the surface of the islets. The coated islets are subsequently embedded in the previously mentioned hydrogel containing thiolated glycosaminoglycans. The suitability of this approach as a matrix for controlled growth factor release has been demonstrated by studying the controlled release of VEGF and bFGF for 14 days. Preliminary tube formation has been quantified on the growth factor loaded hydrogels. This approach should facilitate blood vessel ingrowth towards the embedded islets and maintain islet round morphology and functionality upon implantation

Poly(amido amine)-based multilayered thin films on 2D and 3D supports for surface-mediated cell transfection

Two linear poly(amido amine)s, pCABOL and pCHIS, prepared by polyaddition of cystamine bisacrylamide (C) with 4-aminobutanol (ABOL) or histamine (HIS), were explored to form alternating multilayer thin films with DNA to obtain functionalized materials with transfection capacity in 2D and 3D. Therefore, COS-7 cells were cultured on top of multilayer films formed by layer-by-layer dipcoating of these polymers with GFP-encoded pDNA, and the effect of the number of layers and cell seeding density on the transfection efficiency was evaluated. Multilayer films with pCABOL were found to be superior to pCHIS in facilitating transfection, which was attributed to higher incorporation of pDNA and release of the transfection agent. High amounts of transfected cells were obtained on pCABOL films, correlating proportionally over a wide range with seeding density. Optimal transfection efficiency was obtained with pCABOL films composed of 10 bilayers. Further increase in the number of bilayers only marginally increased transfection efficiency. Using the optimal multilayer and cell seeding conditions, pCABOL multilayers were fabricated on poly(ε-caprolactone) (PCL), heparinized PCL (PCL-HEP), and poly(lactic acid) (PLA) disks as examples of common biomedical supports. The multilayers were found to completely mask the properties of the original substrates, with significant improvement in cell adhesion, which is especially pronounced for PCL and PLA disks. With all these substrates, transfection efficiency was found to be in the range of 25-50% transfected cells. The pCABOL/pDNA multilayer films can also conveniently add transfection capability to 3D scaffolds. Significant improvement in cell adhesion was observed after multilayer coating of 3D-plotted fibers of PCL (with and without an additional covalent heparin layer), especially for the PCL scaffold without heparin layer and transfection was observed on both 3D PCL and PCL-HEP scaffolds. These results show that layer-by-layer dip-coating of pCABOL with functional DNA is an easy and inexpensive method to introduce transfection capability to biomaterials of any nature and shape, which can be beneficially used in various biomedical and tissue engineering applications

Stranieri. Itinerari di vita studentesca tra XIII e XVIII secolo.

Il volume esamina gli studenti stranieri presso l'Università di Padova nella lunga diacronia, a partire dal XIII fino al XVIII secolo. La mobilità studentesca è analizzata attraverso tre momenti: l'arrivo a Padova; l'inserimento nella città e i diversi aspetti della vita studentesca; il ritorno in patria, i ricordi e le opportunità offerte dal soggiorno patavino

Optimization of Anti-kinking Designs for Vascular Grafts Based on Supramolecular Materials

Synthetic vascular grafts to be applied as access grafts for hemodialysis often require anti-kinking properties. Previously, electrospun microporous vascular implants based on synthetic supramolecular materials have been shown to perform adequately as resorbable grafts due to the microstructures, thereby enabling attraction of endogenous cells and consecutive matrix production in situ. Here, we use supramolecular materials based on hydrogen bonding interactions between bisurea (BU) or 2-ureido-4[1H]-pyrimidinones (UPy) to produce microporous anti-kinking tubular structures by combining solution electrospinning with 3D printing. A custom-made rational axis for 3D printing was developed to produce controlled tubular structures with freedom in design in order to print complex tubular architectures without supporting structures. Two different tubular grafts were developed, both composed of a three-layered design with a 3D printed spiral sandwiched in between luminal and adventitial electrospun layers. One tubular scaffold was composed of BU-polycarbonate electrospun layers with 3D printed polycaprolactone (PCL) strands in between for dimensional stability, and the other graft fully consisted of supramolecular polymers, using chain-extended UPy-PCL as electrospun layers and a bifunctional UPy-PCL for 3D printing. Both grafts, with a 3D printed spiral, demonstrated a reproducible dimensional stability and anti-kinking behavior under bending stresses