Search results for "Thermally induced"
showing 8 items of 8 documents
PLLA scaffolds with controlled architecture as potential microenvironment for in vitro tumor model
2019
Abstract The "microenvironment" where a tumor develops plays a fundamental role in determining its progression, the onset of metastasis and, eventually, its resistance to therapies. Tumor cells can be considered more or less invasive depending both on the nature of the cells and on the site where they are located. Commonly adopted laboratory culture protocols for the investigation of tumor cells take usually place on standard two-dimensional supports. However, such cultures do not allow for reproduction of the biophysical properties of the tumor’s microenvironment, thus causing the cells to lose most of their relevant characteristics. In this work MDA-MB 231 breast cancer cells were cultiva…
Thermally Induced Structural Modification of Silica Nanoparticles Investigated by Raman and Infrared Absorption Spectroscopies
2010
We report an experimental investigation by Raman and infrared (IR) absorption spectroscopies on the structural modifications induced by isochronal thermal treatments on amorphous SiO2 nanoparticles (fumed silica). In particular, three different commercial types of this material, characterized by particle mean diameters of 7, 14, and 40 nm, were subjected to thermal treatments from 100 up to 1000 °C. We found that some properties of fumed silica, such as the SiOSi mean bond angle, ring size distribution, and surface adsorbed water content, are drastically different from those of common bulk silica materials and intimately related to the particles' dimension. The SiOSi mean bond angle, probed…
PLLA scaffolds based on thermally induced phase separation: morphology, cell seeding and proliferation
2009
Effect of Polyhydroxyalkanoate (PHA) Concentration on Polymeric Scaffolds Based on Blends of Poly-L-Lactic Acid (PLLA) and PHA Prepared via Thermally…
2022
Hybrid porous scaffolds composed of both natural and synthetic biopolymers have demonstrated significant improvements in the tissue engineering field. This study investigates for the first time the fabrication route and characterization of poly-L-lactic acid scaffolds blended with polyhydroxyalkanoate up to 30 wt%. The hybrid scaffolds were prepared by a thermally induced phase separation method starting from ternary solutions. The microstructure of the hybrid porous structures was analyzed by scanning electron microscopy and related to the blend composition. The porosity and the wettability of the scaffolds were evaluated through gravimetric and water contact angle measurements, respective…
USO DI TECNICHE AVANZATE PER LA OTTIMIZZAZIONE STRUTTURALE E FUNZIONALE DI SCAFFOLD COMPOSITI POLIMERO-CARICA INORGANICA PER LA RIGENERAZIONE OSSEA.
2020
PLLA-BASED SCAFFOLDS FOR OSTEOCHONDRAL TISSUE REGENERATION VIA THERMALLY INDUCED PHASE SEPARATION TECHNIQUE
L’ingegneria tessutale (TE) è una scienza multidisciplinare che mira a progettare e sviluppare sostituti biologici per migliorare, riparare e/o sostituire i tessuti negli organismi umani. Sulla base della tipica triade dell’ingegneria tessutale è incentrato il primo capitolo Scaffold, Source and Signal; lo scaffold funge da struttura tridimensionale, le cellule rappresentano la source mentre il bioreattore fornisce gli adeguati segnali chimico/fisici. In questo lavoro di tesi sono stati presi in considerazione tutti e tre questi aspetti avendo come obiettivo la rigenerazione osteocondrale. La guarigione dei difetti osteocondrali, riguardanti le lesioni della cartilagine che si esten- dono f…
Synthesis, characterization and foaming of PHEA-PLLA, a new graft copolymer for biomedical engineering
2014
Abstract In this study a chemical grafting procedure was set up in order to link high molecular weight poly L-lactic acid (PLLA) chains to the hydrophilic α,β-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) backbone. A graft copolymer named PHEA-g-PLLA (or simply PHEA–PLLA) was obtained bearing a degree of derivatization of 1.0 mol.% of PLLA as grafted chain. This new hybrid derivative offers both the opportune crystallinity necessary for the production of scaffolds trough a thermally induced phase separation (TIPS) technique and the proper chemical reactivity to perform further functionalizations with bio-effectors and drugs. PHEA–PLLA porous scaffolds for tissue engineering applications were…