Search results for " Biochimica"
showing 10 items of 642 documents
Bio-affinity of MC3T3-E1 osteoblastic cells with polymeric scaffold in Poly L-Lactid Acid (PLLA) for bone substitution.
2009
Damage to an organ or tissue remains a problem despite advances in medical technology. Available treatments include organs transplantation, surgical reconstruction such as mechanical devices. However, all these methodologies have several contraindications. In recent years, tissue engineering methods is considered as means to replace diseased or damaged organs. For these kind of application, the choice of scaffolding material is crucial to the success of the technique. In the function of the application, the synthetic scaffolds should meet several criteria, including: good biocompatibility, sufficient mechanical properties, and adequate biodegradability. The aim of our study was to evaluate …
Integration of PCL and PLA in a monolithic porous scaffold for interface tissue engineering.
2016
A novel bi-layered multiphasic scaffold (BLS) have been fabricated for the first time by combining melt mixing, compression molding and particulate leaching. One layer has been composed by polylactic acid (PLA) presenting pore size in the range of 90-110µm while the other layer has been made of polycaprolactone (PCL) with pores ranging from 5 to 40µm. The different chemo-physical properties of the two biopolymers combined with the tunable pore architecture permitted to realize monolithic functionally graded scaffolds engineered to be potentially used for interface tissues regenerations. BLS have been characterized from a morphological and a mechanical point of view. In particular, mechanica…
3D polylactide-based scaffolds for studying human hepatocarcinoma processes in vitro
2012
We evaluated the combination of leaching techniques and melt blending of polymers and particles for the preparation of highly interconnected three-dimensional polymeric porous scaffolds for in vitro studies of human hepatocarcinoma processes. More specifically, sodium chloride and poly(ethylene glycol) (PEG) were used as water-soluble porogens to form porous and solvent-free poly(L,D-lactide) (PLA)-based scaffolds. Several characterization techniques, including porosimetry, image analysis and thermogravimetry, were combined to improve the reliability of measurements and mapping of the size, distribution and microarchitecture of pores. We also investigated the effect of processing, in PLA-ba…
A COMPOSITE PLLA SCAFFOLD FOR REGENERATION OF COMPLEX TISSUES
2010
A composite biodegradable scaffold incorporating an integrated network of synthetic blood vessels was designed and prepared, in line with the requirements of a scaffold effectively supporting the regeneration of highly vascularized tissues. In other words, this composite scaffold should allow the regeneration of complex injured tissue (e.g. dermis) and, at the same time, favour the development of a vascular network on its inner, i.e. a 3D polymeric scaffolds embedding synthetic blood vessel-like structures for nutrient supply and metabolite removal. PLLA assures a high degree of biocompatibility and a low level of inflammation response upon implantation, while the embedded tubular vessel-li…
Selective G-quadruplex stabilizers: Schiff-base metal complexes with anticancer activity
2014
The affinity of three square-planar nickel(II) (1), copper(II) (2) and zinc(II) (3) Schiff-base complexes for wild-type human telomeric (h-Telo) and protooncogene c-myc G-quadruplex (G4) DNA was investigated by UV-visible absorption spectroscopy and circular dichroism. DNA-binding constants (Kb) were determined by spectrophotometric titrations for both G4-DNA and B-DNA. The results obtained point out that the three metal complexes selectively bind G4-DNA with higher affinity, up to two orders of magnitude, with respect to B-DNA. The nickel(II) complex 1 was found to be the most effective G4-DNA stabilizer and the Kb values decrease in the order 1 > 2 ≈ 3. Innovative computational investigat…
Scienze Naturali
2017
Il corso è stato progettato per disporre di tutti gli argomenti previsti da programma ministeriale per il quinto anno dei Licei (Chimica organica, Genetica, Biochimica, Microbiologia, Biotecnologie e Scienze della Terra) in un unico volume. Gli argomenti proposti sono trattati in maniera organica, evidenziando i possibili punti di contatto tra le differenti discipline e abituando lo studente a sviluppare una concezione liquida del sapere. La didattica e la struttura proposte sono finalizzate alla conoscenza e alla comprensione dei fenomeni che contraddistinguono la materia, la natura, gli esseri viventi e l’uomo e l’ambiente nel quale vive e col quale interagisce. Il corso concorre alla cos…
Shedding of Membrane Vesicles Mediates Fibroblast Growth Factor-2 Release from Cells
2003
Fibroblast growth factor-2 (FGF-2), a polypeptide with regulatory activity on cell growth and differentiation, lacks a conventional secretory signal sequence, and its mechanism of release from cells remains unclear. We characterized the role of extracellular vesicle shedding in FGF-2 release. Viable cells released membrane vesicles in the presence of serum. However, in serum-free medium vesicle shedding was dramatically down-regulated, and the cells did not release FGF-2 activity into their conditioned medium. Addition of serum to serum-starved cells rapidly induced intracellular FGF-2 clustering under the plasma membrane and into granules that colocalized with patches of the cell membrane …
The synergistic effect of SAHA and parthenolide in MDA-MB231 breast cancer cells
2014
Abstract: The sesquiterpene lactone Parthenolide (PN) exerted a cytotoxic effect on MDA-MB231 cells, a triple-negative breast cancer (TNBC) cell line, but its effectiveness was scarce when employed at low doses. This represents an obstacle for a therapeutic utilization of PN. In order to overcome this difficulty we associated to PN the suberoylanilide hydroxamic acid (SAHA), an histone deacetylase inhibitor. Our results show that SAHA synergistically sensitized MDA-MB231 cells to the cytotoxic effect of PN. It is noteworthy that treatment with PN alone stimulated the survival pathway Akt/mTOR and the consequent nuclear translocation of Nrf2, while treatment with SAHA alone induced autophagi…
Quality changes in fresh-cut mango cubes submitted to different gas partial pressure of active MAPs
2018
The study was performed to assess chemical-physical and sensory quality changes in 4±1°C stored fresh-cut mangos and to test the effect of active modified atmosphere packaging (MAP) with different gas partial pressures. Sicilian fruits of ‘Keitt’ mango (Mangifera indica L.) were immerged in hydrogen peroxide (H2O2) after being peeled. Next, the flesh was cut in cubes and dipped in citric acid (0.5%, w/v) and ascorbic acid (0.5%, w/v). Treated fruits were placed in a non-perforated high density polyethylene package flushing different gas mixtures and kept at 4°C for 21 days. We used four different gas partial pressures: a) 60 kPa N2, 30 kPa CO2 and 10 kPa O2; b) 30 kPa CO2 and 70 kPa N2; c) …
La coltivazione della Papaya in Sicilia: qualità dei frutti e prospettive
2018
Data la numerosità dei genotipi di papaia coltivati in Sicilia si è resa necessaria una caratterizzazione qualitativa degli stessi. In questo studio sono stati confrontati, da un punto di vista pomologico, chimico-fisico, nutraceutico e sensoriale, i frutti di 5 differenti genotipi di papaia nell’ottica di individuarne e definirne qualità e rispondenza per il mercato locale ed europeo.