Sviluppo e caratterizzazione di materiali biomimetici e bioattivi per la rigenerazione dentale

Lo scopo di questo lavoro di tesi è quello di sviluppare un prototipo di scaffold tri-strato che favorisca la rigenerazione del tessuto parodontale, mimando i differenti tessuti mineralizzati del parodonto per il trattamento, in particolare, delle parodontiti avanzate.Le prime attività si baseranno sulla definizione di un metodo che permetta la standardizzazione della fase dei lavaggi inerente al processo di produzione dello scaffold parodontale. Tale fase risulta, infatti, altamente operatore-dipendente e pertanto l’acqua contenuta prima e dopo il lavaggio, non essendo controllata, influenza diversamente le caratteristiche del prodotto finale. Infine, per garantire l’assottigliamento dello strato intermedio collagenico (tale da rispettare le caratteristiche strutturali del legamento parodontale in vivo) saranno testate diverse condizioni di liofilizzazione.

Studies towards the total synthesis of penicillipyrone b via a biomimetic approach

Pennicillipyrone A and B are two novel meroterpenoids isolated from the marine-derived fungus Penicilliump sp. Although a preliminary toxicity studies demonstrated the bioactivity of penicillipyrone A to be far superior to that of its congener penicillipyrone B, we were intrigued by its structure. Moreover, it appeared as though one could design an efficient total synthesis based on chemistry that was familiar to our laboratory. The purpose of this project was the study of a new synthesis of Pennicillipyrone B by way of a doubley-biomimetic approach. The intended approach proceeds through a polyene cascade reaction terminated by a nucleophilic pyrone - a reaction not yet known in the literature for the construction of this type of scaffold. During the course of this study we have learned about the unanticipated reactivity of C2 substituted keto-dioxinones with regard to self-condensation. In addition, four new compounds were synthesized and two synthetic routes to the target molecule are presented.

Finite element modeling of flow/compression-induced deformation of alginate scaffolds for bone tissue engineering

Trauma or degenerative diseases such as osteonecrosis may determine bone loss whose recover is promised by a "tissue engineering“ approach. This strategy involves the use of stem cells, grown onboard of adequate biocompatible/bioreabsorbable hosting templates (usually defined as scaffolds) and cultured in specific dynamic environments afforded by differentiation-inducing actuators (usually defined as bioreactors) to produce implantable tissue constructs. The purpose of this thesis is to evaluate, by finite element modeling of flow/compression-induced deformation, alginate scaffolds intended for bone tissue engineering. This work was conducted at the Biomechanics Laboratory of the Institute of Biomedical and Neural Engineering of the Reykjavik University of Iceland. In this respect, Comsol Multiphysics 5.1 simulations were carried out to approximate the loads over alginate 3D matrices under perfusion, compression and perfusion+compression, when varyingalginate pore size and flow/compression regimen. The results of the simulations show that the shear forces in the matrix of the scaffold increase coherently with the increase in flow and load, and decrease with the increase of the pore size. Flow and load rates suggested for proper osteogenic cell differentiation are reported.