777 research outputs found
Le indagini sull'acropoli
No full textLe indagini condotte sull'acropoli di Populonia nella campagna di scavi del 2007, cui M.L. Gualandi ha partecipato come responsabile dell'équipe di ricerca dell'Università di Pisa
Lavori in corso: primi risultati della campagna 2003
No full textI risultati degli scavi archeologici sull'acropoli di Populonia. Campagna 2003
Introduzione. Produzione, conservazione e interpretazione dei dati archeologici per lo studio dell’edilizia abitativa antica e medievale nella città di Pisa
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Cell delivery for regenerative medicine by using bioresorbable polymers
No full textFor regenerative medicine, the development of an optimal biomaterial system to deliver cells is crucial to precisely locate cells in the target site while preserving cell activity and function. In addition, the cell delivery construct should have the same instructive role as the extracellular microenvironment that naturally surrounds cells within a tissue. This chapter presents an overview of main concepts for the design of bioresorbable constructs for cell delivery and tissue regeneration, namely, types of polymers with recognized biocompatibility and bioresorbability, mechanical properties, structural architecture, and mass transport of the construct, as well as incorporation of biochemical and biophysical cues to provide instructive cell signaling and scaffold bioactivity. Regulatory and clinical aspects are mentioned at the end as they are important to ensure commercial success for these cutting-edge products
Porous Polymeric Bioresorbable Scaffolds for Tissue Engineering
No full textTissue engineering is a discipline that aims at regenerating damaged biological tissues by using a cell-construct engineered in vitro made of cells grown into a porous 3D scaffold. The role of the scaffold is to guide cell growth and differentiation by acting as a bioresorbable temporary substrate that will be eventually replaced by new tissue produced by cells. As a matter or fact, the obtainment of a successful engineered tissue requires a multidisciplinary approach that must integrate the basic principles of biology, engineering and material science.
The present Ph.D. thesis aimed at developing and characterizing innovative polymeric bioresorbable scaffolds made of hydrolysable polyesters. The potentialities of both commercial polyesters (i.e. poly-e-caprolactone, polylactide and some lactide copolymers) and of non-commercial polyesters (i.e. poly-w-pentadecalactone and some of its copolymers) were explored and discussed.
Two techniques were employed to fabricate scaffolds: supercritical carbon dioxide (scCO2) foaming and electrospinning (ES). The former is a powerful technology that enables to produce 3D microporous foams by avoiding the use of solvents that can be toxic to mammalian cells. The scCO2 process, which is commonly applied to amorphous polymers, was successfully modified to foam a highly crystalline poly(w-pentadecalactone-co-e-caprolactone) copolymer and the effect of process parameters on scaffold morphology and thermo-mechanical properties was investigated.
In the course of the present research activity, sub-micrometric fibrous non-woven meshes were produced using ES technology. Electrospun materials are considered highly promising scaffolds because they resemble the 3D organization of native extra cellular matrix. A careful control of process parameters allowed to fabricate defect-free fibres with diameters ranging from hundreds of nanometers to several microns, having either smooth or porous surface. Moreover, versatility of ES technology enabled to produce electrospun scaffolds from different polyesters as well as “composite” non-woven meshes by concomitantly electrospinning different fibres in terms of both fibre morphology and polymer material. The 3D-architecture of the electrospun scaffolds fabricated in this research was controlled in terms of mutual fibre orientation by properly modifying the instrumental apparatus. This aspect is particularly interesting since the micro/nano-architecture of the scaffold is known to affect cell behaviour.
Since last generation scaffolds are expected to induce specific cell response, the present research activity also explored the possibility to produce electrospun scaffolds bioactive towards cells. Bio-functionalized substrates were obtained by loading polymer fibres with growth factors (i.e. biomolecules that elicit specific cell behaviour) and it was demonstrated that, despite the high voltages applied during electrospinning, the growth factor retains its biological activity once released from the fibres upon contact with cell culture medium. A second fuctionalization approach aiming, at a final stage, at controlling cell adhesion on electrospun scaffolds, consisted in covering fibre surface with highly hydrophilic polymer brushes of glycerol monomethacrylate synthesized by Atom Transfer Radical Polymerization. Future investigations are going to exploit the hydroxyl groups of the polymer brushes for functionalizing the fibre surface with desired biomolecules.
Electrospun scaffolds were employed in cell culture experiments performed in collaboration with biochemical laboratories aimed at evaluating the biocompatibility of new electrospun polymers and at investigating the effect of fibre orientation on cell behaviour. Moreover, at a preliminary stage, electrospun scaffolds were also cultured with tumour mammalian cells for developing in vitro tumour models aimed at better understanding the role of natural ECM on tumour malignity in vivo
Proposta per una nuova periodizzazione
No full textI criteri e la metodologia seguiti per la messa a punto della periodizzazione delle vicende storiche di Populonia, quali emergono dai risultati delle campagne di scavo
L'immagine dei neri nel mondo greco e romano
No full textAttraverso l'analisi delle modalità con cui i Greci e i Romani hanno raffigurato i neri è possibile formulare un'ipotesi interpretativa dell'iconografia di un mosaico rinvenuto in un edificio termale di età romana sull'acropoli di Populonia (LI
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