Search results for "Chemical engineering"

Wet Chemistry and Peptide Immobilization on Polytetrafluoroethylene for Improved Cell-adhesion

2016

Endowing materials surface with cell-adhesive properties is a common strategy in biomaterial research and tissue engineering. This is particularly interesting for already approved polymers that have a long standing use in medicine because these materials are well characterized and legal issues associated with the introduction of newly synthesized polymers may be avoided. Polytetrafluoroethylene (PTFE) is one of the most frequently employed materials for the manufacturing of vascular grafts but the polymer lacks cell adhesion promoting features. Endothelialization, i.e., complete coverage of the grafts inner surface with a confluent layer of endothelial cells is regarded key to optimal perfo…

Antimicrobial packaging based on ɛ-polylysine bioactive film for the control of mycotoxigenic fungi in vitro and in bread

2017

Abstract ɛ‐Poly‐l‐lysine (ɛ‐PL) is a cationic peptide with a broad‐spectrum antimicrobial activity. This study investigates the use of ɛ‐PL as natural antimicrobial to inhibit fungal growth and to reduce aflatoxins (AFs) production. Antifungal activity of starch biofilms with different concentrations of ɛ‐Poly‐l‐lysine (ɛ‐PL) was determined in solid medium against Aspergillus parasiticus (AFs producer) and Penicillium expansum. Then, biofilms were tested as antimicrobial devices for the preservation of bread loaf inoculated with A. parasiticus CECT 2681 and P. expansum CECT 2278. Shelf life and AFs content were examined. Biofilms with concentrations of ɛ‐PL less than 1.6 mg/cm2 showed no fu…

How Can Interleukin-1 Receptor Antagonist Modulate Distinct Cell Death Pathways?

2018

Multiple mechanisms of cell death exist (apoptosis, necroptosis, pyroptosis) and the subtle balance of several distinct proteins and inhibitors tightly regulates the cell fate toward one or the other pathway. Here, by combining coimmunoprecipitation, enzyme assays, and molecular simulations, we ascribe a new role, within this entangled regulatory network, to the interleukin-1 receptor antagonist (IL-1Ra). Our study enlightens that IL-1Ra, which usually inhibits the inflammatory effects of IL-1α/β by binding to IL-1 receptor, under advanced pathological states prevents apoptosis and/or necroptosis by noncompetitively inhibiting the activity of caspase-8 and -9. Consensus docking, followed by…

Silica-gelatin hybrid sol-gel coatings: A proteomic study with biocompatibility implications.

2018

Osseointegration, including the foreign body reaction to biomaterials, is an immune‐modulated, multifactorial, and complex healing process in which various cells and mediators are involved. The buildup of the osseointegration process is immunological and inflammation‐driven, often triggered by the adsorption of proteins on the surfaces of the biomaterials and complement activation. New strategies for improving osseointegration use coatings as vehicles for osteogenic biomolecules delivery from implants. Natural polymers, such as gelatin, can mimic Collagen I and enhance the biocompatibility of a material. In this experimental study, two different base sol–gel formulations and their combinati…

A combined physical-chemical and microbiological approach to unveil the fabrication, provenance, and state of conservation of the Kinkarakawa-gami ar…

2020

AbstractKinkarakawa-gami wallpapers are unique works of art produced in Japan between 1870 and 1905 and exported in European countries, although only few examples are nowadays present in Europe. So far, neither the wallpapers nor the composing materials have been characterised, limiting the effective conservation–restoration of these artefacts accounting also for the potential deteriogen effects of microorganisms populating them. In the present study, four Kinkarakawa-gami wallpapers were analysed combining physical–chemical and microbiological approaches to obtain information regarding the artefacts’ manufacture, composition, dating, and their microbial community. The validity of these met…

Sterilization of macroscopic poly(l-lactic acid) porous scaffolds withdense carbon dioxide: Investigation of the spatial penetration of thetreatment …

2016

Abstract In this work the sterilization with dense carbon dioxide of poly( l -lactic acid) (PLLA) porous scaffolds intended for tissue engineering applications was investigated with the main objective of confirming the three-dimensional efficacy of the treatment and of analysing the scaffold properties after CO2 treatment. For this purpose the scaffold was contaminated with a conventional bacterium (Escherichia coli) and with spores (Streptomyces coelicolor), a species more fascinating and difficult to inactivate. Contamination was performed in such a way to soak the whole matrix with bacteria and spores. The effect of pressure and treatment time on the efficacy of the sterilization was eva…

Heat- and pH-induced BSA conformational changes, hydrogel formation and application as 3D cell scaffold

2016

Aggregation and gelation of globular proteins can be an advantage to generate new forms of nanoscale biomaterials based on the fibrillar architecture. Here, we report results obtained by exploiting the proteins' natural tendency to self-organize in 3D network, for the production of new material based on BSA for medical application. In particular, at five different pH values the conformational and structural changes of the BSA during all the steps of the thermal aggregation and gelation have been analyzed by FTIR spectroscopy. The macroscopic mechanical properties of these hydrogels have been obtained by rheological measurements. The microscopic structure of the gels have been studied by AFM…

Guanosine-5'-Monophosphate Polyamine Hybrid Hydrogels: Enhanced Gel Strength Probed by z-Spectroscopy.

2017

The self-assembling tendencies of guanosine-5'-monophosphate (GMP) can be drastically increased using polyamines, with potential applications in the production of biocompatible smart materials, as well as for the design of anti-tumoral drugs based on G-quadruplex stabilization. Results from scanning electron microscopy (SEM), wide angle X-ray scattering (WAXS), rheology and nuclear magnetic resonance (NMR) z-spectroscopy studies are presented.

2020

Worldwide, tons of lignin is produced annually in pulping plants and it is mainly considered as a waste material. Usually lignin is burned to produce energy for the pulping reactors. The production of value-added materials from renewable materials like lignin, has proved to be challenging. In this study, the effects of addition of three different types of lignin in the production of tannin/furanic foams is investigated. The foams were matured, first at 373 K and finally carbonized at 1073 K and the properties of them including mechanical strength, specific surface area and pore development are investigated before and after thermal treatment. According to the results, higher mechanical stren…

FLYCOP: metabolic modeling-based analysis and engineering microbial communities

2018

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