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1.
Sci Rep ; 12(1): 19379, 2022 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-36371472

RESUMO

One method for finding reliable and cost-effective solutions for designing radioisotope production systems is represented by the "digital twin" philosophy of design. Looking at cyclotron solid targets, uncertainties of the particle beam, material composition and geometry play a crucial role in determining the results. The difference between what has been designed and what can be effectively manufactured, where processes such as electroplating are poorly controllable and generate large non-uniformities in deposition, must also be considered. A digital twin, where the target geometry is 3D scanned from real models, can represent a good compromise for connecting "ideal" and "real" worlds. Looking at the 64Ni(p,n)64Cu reaction, different Unstructured-Mesh MCNP6 models have been built starting from the 3D solid target system designed and put into operation by COMECER. A characterization has been performed considering the designed ideal target and a 3D scan of a real manufactured target measured with a ZEISS contact probe. Libraries and physics models have been also tested due to limited cross-section data. Proton spectra in the target volume, 3D proton-neutron-photon flux maps, average energies, power to be dissipated, shut-down dose-rate, 64Cu yield compared with various sources of experimental data and beam axial shifting impact, have been estimated. A digital twin of the 64Ni(p,n)64Cu production device has been characterized, considering the real measured target geometry, paving the way for a fully integrated model suitable also for thermal, structural or fluid-dynamic analyses.

2.
Polymers (Basel) ; 14(20)2022 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-36297937

RESUMO

The aim of the present study was to investigate starch-based materials, prepared in an environmentally friendly way and from renewable resources, suitable for the development of biodegradable active food packaging. For this purpose, a bioactive compound (thymol) was incorporated into thermoplastic starch (TPS) and a TPS blend with poly (ε-caprolactone) (TPS-PCL) by the supercritical CO2 (scCO2) impregnation process. Impregnation experiments with scCO2 were carried out at a pressure of 30 MPa and temperatures in the range of 40-100 °C during 1 to 20 h. The structural, morphological, and thermal properties of the obtained materials were comprehensively evaluated. Bioactive component release kinetic studies were performed in water at 6 °C and 25 °C. It was shown that the scCO2 impregnation process could be successfully employed for thymol loading into TPS and TPS-PCL. The process was significantly influenced by the operating temperature and time as well as content of PCL. The samples showed a controlled release of thymol within seven days with a higher amount of released thymol from the TPS-PCL blend. The obtained materials are solvent-free and release the bioactive component in a controlled manner.

3.
Carbohydr Polym ; 279: 118989, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34980348

RESUMO

Ulomoides dermestoides (UL) are macroinvertebrates insects belonging to Tenebrionidae Coleopteran family. They were used to hasten, in five days, the biodegradation-mineralization of thermoplastic starch (TPS)-poly(lactic acid) (PLA) films, otherwise biodegradable under composting conditions. After the contact of TPS-PLA film with UL for five days, TPS was metabolized and PLA was hydrolysed, as evidenced by decreasing of hydroxyl and carbonyl group peaks intensity by FTIR spectra, increasing of 13% of PLA crystallinity by DSC thermograms, reduction of PLA and TPS thermal stability by TGA analysis; faecal residues evidenced two glass transition temperature Tg, at 33 °C and 57 °C, associated with depolymerized TPS and PLA, respectively. SEM micrographs highlighted consumption of TPS-PLA surface, while GPC analysis showed a decrease in PLA concentration by 20% during contact by UL. Mineralization tests evidenced UL boosted effect on TPS biodigestion-biodegradation (80%) and PLA biodisintegration (50%), envisaging a challenging perspective for end-life management of bioplastics in environmental conditions.


Assuntos
Poliésteres/metabolismo , Amido/metabolismo , Tenebrio/metabolismo , Animais , Biodegradação Ambiental , Varredura Diferencial de Calorimetria , Fezes/química , Temperatura , Termogravimetria
4.
Polymers (Basel) ; 13(7)2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33806055

RESUMO

The hitherto known polyamidoamines (PAAs) are not suitable as structural materials because they are usually water-soluble or swellable in water. This paper deals with the synthesis and characterization of semi-crystalline hydrophobic PAAs (H-PAAs) by combining different bis-sec-amines with bis-acrylamides obtained from C6-C12 bis-prim-amines. H-PAAs were initially obtained in a solution of benzyl alcohol, a solvent suitable for both monomers and polymers. Their number average molecular weights, M¯n, which were determined with 1H-NMR by evaluating the percentage of their terminal units, varied from 6000 to >10,000. The solubility, thermal properties, ignitability and water resistance of H-PAAs were determined. They were soluble in organic solvents, semi-crystalline and thermally stable. The most promising ones were also prepared using a bulk process, which has never been previously reported for PAA synthesis. In the form of films, these H-PAAs were apparently unaffected by water. The films underwent tensile and wettability tests. They showed similar Young moduli (260-263 MPa), whereas the maximum stress and the stress at break depended on the number of methylene groups of the starting bis-acrylamides. Their wettability was somewhat higher than that of common Nylons. Interestingly, none of the H-PAAs considered, either as films or powders, ignited after prolonged exposure to a methane flame.

5.
Polymers (Basel) ; 13(8)2021 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-33919976

RESUMO

Citrus pomace derived from the industrial processing of juice and essential oils mostly consists of pectin, cellulose, hemicellulose, and simple sugars. In this work, citrus pomace waste from an agricultural company in South Italy was used as source of pectin. The extraction conditions of the polysaccharide were optimized using a suitable combination of time and a concentration of a mild organic solvent, such as acetic acid; thus recovering high Mw pectin and bioactive molecules (flavonoids and polyphenols). The pectin was structurally (GPC, FTIR), morphologically (SEM), thermally (TGA/DTG), and mechanically characterized, while bioactive molecules were separated and the total phenolic content (TPC) and total flavonoids content (TFC) were evaluated. With the aim to develop novel biocomposite-based materials, the pectin extracted from citrus waste was reinforced with different amounts of lignocellulose fractions also recovered from citrus waste after polysaccharide extraction, according to a "zero waste" circular economy approach. The prepared biocomposites were morphologically and mechanically characterized to be used as biodegradable mulching systems for crop protection. Thus, the citrus waste biomass was recovered, fractionated into its main raw materials, and these were recombined to develop novel upgraded biocomposites for mulching applications, by means of a cost-effective and eco-sustainable approach.

6.
N Biotechnol ; 60: 146-158, 2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33068793

RESUMO

Renewable bio-based polymers are one of the effective answers that the bioeconomy offers to solve the environmental emergency connected to plastics and more specifically fossil-based plastics. Previous studies have shown that more than 70 % of the natural capital cost associated with plastic derives from the extraction and processing of fossil raw materials and that the price of fossil plastic would be on average 44 % higher if such impact was fully paid by businesses. The disclosure of the hidden costs of plastics will contribute to dispelling the myth of the expensiveness of renewable polymers. Nevertheless, the adoption of bio-based plastics in the market must be motivated by their functional properties and not merely by their green credentials. This article highlights some successful examples of synergies between chemistry and biotechnology in achieving a new generation of bio-based monomers and polymers. Their success is justified by the combination of scientific advances with positive environmental and social fallouts.


Assuntos
Biotecnologia , Plásticos/metabolismo , Polímeros/metabolismo , Biodegradação Ambiental , Plásticos/química , Polímeros/química
7.
Pest Manag Sci ; 77(2): 646-658, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33012130

RESUMO

BACKGROUND: The organic extracts (OEs) of Dittrichia viscosa, a ruderal plant common in the Mediterranean regions, proved to have herbicidal properties. In order to improve OE effectiveness and to develop novel eco-friendly bioherbicidal products, different amounts of OE were included in poly(butylene succinate)- and polycaprolactone-based films (PBS and PCL, respectively). Particular attention was given to the study of interactions between the polymers and OEs, with a deep spotlight concerning the influence of OEs on structural, morphological and thermal properties of both polymers, in order to assess the OE releasing kinetics from the matrices and its tuned herbicidal action against seeds. RESULTS: The bioassays carried out on Lepidium sativum and Phelipanche ramosa seeds evidenced a more controlled and effective OE release by PBS than PCL, and a longer lasting efficacy by the polymers with a higher OE content. The chemical-physical analyses were performed on films before and after biological assays. The thermogravimetric analysis confirmed that OE was a thermal stabilizer of the polymer; the presence of OE and polymer separated degradative kinetics suggested that only a partial and functional miscibility between polymers and OE occurred. The morphological analysis confirmed the good OE dispersion between PBS and PCL molecular chains. Infrared spectroscopy highlighted the enhanced hydrolysed structure of the doped polymers after the bioassays. These outcomes well matched the quantitative information outlined by release kinetics. DISCUSSION: The use of biodegradable polymers allows the effectiveness and tuning of the release of the formulated bioactive compounds to be improved. The easy-to-obtain and easy-to-formulate OE could become a suitable and environmentally friendly instrument in weed management programmes.


Assuntos
Asteraceae , Herbicidas , Herbicidas/farmacologia , Extratos Vegetais/farmacologia , Poliésteres , Polímeros
8.
Nanomaterials (Basel) ; 10(9)2020 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-32911815

RESUMO

Thermo-responsive copolymers based on oligo(ethylene glycol) methacrylate (OEGMA, Mn = 300 g/mol) and pentafluorostyrene (PFS), coded PFG, were synthesized by RAFT polymerization, using a trithiocarbonate (CTTPC) as controlling agent. Different molar masses were targeted and dispersities lower than 1.51 were obtained. The thermally triggered self-assembly of the resulting PFG copolymers in water was investigated by dynamic light scattering (DLS). The lower critical solution temperature (LCST) slightly increased with the molecular weight in the 26-30 °C temperature range, whereas the sizes of the intermicellar aggregates formed upon self-assembly tended to decrease with increasing molecular weights (ranging from 1415 to 572 nm). The resulting thermally-induced polymer aggregates were then used to encapsulate and remove organic contaminants from water. Nile Red (NR) and Thiazole yellow G (TYG) were employed as hydrophobic and hydrophilic model contaminants, respectively. Experimental results evidenced that higher molecular weight copolymers removed up to 90% of NR from aqueous solution, corresponding to about 10 mg of dye per g of copolymer, regardless of NR concentration. The removal of TYG was lower with respect to NR, decreasing from about 40% to around 20% with TYG concentration. Finally, the copolymers were shown to be potentially recycled and reused in the treatment of contaminated water.

9.
Carbohydr Polym ; 233: 115839, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32059889

RESUMO

Wound healing can lead to complex clinical problems, hence finding an efficient approach to enhance the healing process is necessary. An ideal wound dressing should treat wounds at reasonable costs, with minimal inconveniences for the patient. Chitosan is one of the most investigated biopolymers for wound healing applications due to its biocompatibility, biodegradability, non-toxicity, and antimicrobial activity. Moreover, chitosan and its derivative have attracted numerous attentions because of the accelerating wound healing, and easy processability into different forms (gels, foams, membranes, and beads). All these properties make chitosan-based materials particularly versatile and promising for wound dressings. Besides, secondary natural metabolites could potentially act like the antimicrobial and anti-inflammatory agents and accelerate the healing process. This review collected almost all studies regarding natural compounds applications in wound healing by focusing on the chitosan-based bioactive wound dressing systems. An accurate analysis of different chitosan formulations and the influence of bioactive compounds on their wound healing properties are reported.


Assuntos
Antibacterianos/uso terapêutico , Infecções Bacterianas/tratamento farmacológico , Bandagens , Quitosana/análogos & derivados , Cicatrização/efeitos dos fármacos , Animais , Humanos
10.
Carbohydr Polym ; 230: 115627, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31887941

RESUMO

In this study, chitosan (C) tripolyphosphate (T) sub-micro particles containing ungeremine (CTUn), an alkaloid particularly active against Penicilliumroqueforti, a fungus responsible of the bakery products deterioration, were prepared through external gelation crosslinking process. The particles were included in a thermoplastic starch based polymer Mater-Bi (MBi), and MBi/CTUn bioactive biocomposites were obtained. The films showed bioactivity against P. roqueforti. In particular, the bioassays were performed on films with different concentration of CTUn and at different pH values. CTUn particles influenced MBi crystallization (DSC analysis) and promoted thermal degradation of MBi starch component (TGA). Morphological analysis confirmed even distribution of sub-micro particles into the polymeric matrix. Water permeability slightly increased, as expected, whereas oxygen permeability decreased. Tensile tests showed CTUN sub-microparticles improved rigidity and tensile strength of the films at the expense of ductility. Finally, MBi/CTUn biocomposites evidenced interesting performances potentially exploitablein bioactive bakery based food packaging materials.


Assuntos
Antifúngicos/química , Quitosana/análogos & derivados , Amido/análogos & derivados , Antifúngicos/farmacologia , Embalagem de Alimentos/métodos , Nanocompostos/química , Oxigênio/química , Penicillium/efeitos dos fármacos , Resistência à Tração
11.
Nucl Med Biol ; 74-75: 12-18, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31421441

RESUMO

INTRODUCTION: The demand for Gallium-68 (68Ga) for labelling PET radiopharmaceuticals has increased over the past few years. 68Ga is obtained through the decayed parent radionuclide 68Ge using commercial 68Ge/68Ga generators. The principal limitation of commercial 68Ge/68Ga generators is that only a limited and finite quantity of 68Ga (<1.85 GBq at start of synthesis) may be accessed. The focus of this study was to investigate the use of a low energy medical cyclotron for the production of greater quantities of 68Ga and to develop an automated and rapid procedure for processing the product. METHODS: Enriched ZnCl2 was electrodeposited on a platinum backing using a NH4Cl (pH 2-4) buffer. The Zn target was irradiated with GE PETtrace 880 at 35 µA and 14.5 and 12.0 MeV beam energy. The irradiated Zn target was purified using octanol resin on an automated system. RESULTS: Following the described procedure, 68Ga was obtained in 6.30 ±â€¯0.42 GBq after 8.5 min bombardment and with low radionuclidic impurities (66Ga (<0.005%) and 67Ga (<0.09%)). Purification on a single octanol resin gave 82% recovery with resulting [68Ga]GaCl3 obtained in 3.5 mL of 0.2 M HCl. [68Ga]GaCl3 production from irradiation to final product was <45 min. To highlight the utility of the automated procedure, [68Ga]Ga-DOTA-TATE labelling was incorporated to give 1.56 GBq at EOS of the labelled peptide with RCY of >70%. CONCLUSIONS: A straightforward procedure for producing 68Ga on a low energy medical cyclotron was described. Current efforts are focus on high activity production and radiolabelling using solid target produced 68Ga.


Assuntos
Ciclotrons/instrumentação , Radioisótopos de Gálio/metabolismo , Marcação por Isótopo/métodos , Compostos Organometálicos/química , Geradores de Radionuclídeos/instrumentação , Compostos Radiofarmacêuticos/metabolismo , Gálio/química , Radioisótopos de Gálio/isolamento & purificação , Humanos , Compostos Organometálicos/isolamento & purificação , Compostos Organometálicos/metabolismo , Compostos Radiofarmacêuticos/isolamento & purificação
12.
Carbohydr Polym ; 202: 72-83, 2018 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-30287045

RESUMO

Nowadays, the need of novel strategies to repair and regenerate bone defects in the field of biomedical applications has increased. Novel approaches include the design of natural bioactive scaffolds mimicking bone tissue. These bioactive scaffolds have to possess biophysical properties suitable to address biological response towards newly bone tissue formation. In particular, scaffold porosity and pore size play a pivotal role in cell migration, adhesion and proliferation, thus increasing cell-material surface interaction and osteogenic signals transmission. Here we propose the development of macroporous alginate foams (MAFs) with porous and well interconnected structure, useful to enhance growth and osteogenic differentiation of human Mesenchymal Stem Cells (hMSCs). Moreover, in this study we report a new method for MAFs fabrication based on the combination of internal gelation technique with gas foaming. Strontium was employed in combination with calcium as cross-linking agent for the alginate chains and as enhancer of the osteogenic differentiation. The influence of strontium ions on the gelation kinetics, physical properties and degradation in physiological medium of MAFs was investigated. Our results suggest that the combination of internal gelation technique with gas foaming followed by freeze-drying is an easy and straightforward procedure to prepare alginate foams with high porosity and interconnectivity, able to support cell infiltration. Finally, biological assays showed how scaffolds with high strontium content are able to support cell growth and differentiation in long times by promoting osteogenic marker expression.


Assuntos
Alginatos/farmacologia , Osso e Ossos/efeitos dos fármacos , Reagentes de Ligações Cruzadas/farmacologia , Estrôncio/farmacologia , Engenharia Tecidual , Alginatos/química , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Reagentes de Ligações Cruzadas/química , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Tamanho da Partícula , Porosidade , Estrôncio/química , Propriedades de Superfície
13.
Appl Radiat Isot ; 140: 24-28, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29936272

RESUMO

AIM: This work describes a small-scale production of iodine-124 using a 16.5 MeV cyclotron, and a subsequent validation of the formulated sodium [124I]iodide solution for routinely clinical applications. METHODS: Iodine-124 (124I) was produced via the 124Te(p, n)124I reaction using a 16.5 MeV GE PETtrace® cyclotron. Irradiation was performed with a pre-prepared solid target consisting of [124Te]TeO2 (99.93%) and Al2O3. Different layer thicknesses, irradiation and extraction parameters were tested. After irradiation at the cyclotron, the shuttle with irradiated material was transferred fully automatically via a tube system to the Comecer ALCEO® Halogen 2.0 extraction unit. Iodine-124 was subsequently extracted in form of sodium [124I]iodide ([124I]NaI) in 0.05 N aqueous NaOH solution, followed by reconstitution and validation for preclinical and clinical uses. RESULTS: Good result was achieved using a beam degradation foil of 500 µm thickness in combination with beam currents between 10 and 15 µA. Under these conditions, up to 150 MBq no-carrier-added [124I]NaI was obtained after a 2 h irradiation time in less than 500 µl 0.05 N NaOH. Isolation of [124I]NaI, including evaporation and extraction at the ALCEO® Halogen EVP unit was accomplished in 90 min 24 h after production (irradiation), the amount of iodine-123 as assessed by gamma-ray spectroscopy was less than 1.5%. The undesirable iodine-125 was not detectable by gamma spectroscopy. The extracted [124I]NaI could be used directly for radiolabeling purposes, and after buffering with phosphate buffered saline (PBS) and sterile filtration for clinical applications. CONCLUSIONS: Through the optimized conditions for irradiation and extraction, iodine-124 was produced in good radiochemical yields and high radionuclide purity. The generated injectable [124I]NaI solution was sterile, non-pyrogenic and ready for preclinical and clinical applications after a sterile filtration through a 0.22 µm membrane filter.


Assuntos
Radioisótopos do Iodo/isolamento & purificação , Radioquímica/métodos , Compostos Radiofarmacêuticos/isolamento & purificação , Ciclotrons , Desenho de Equipamento , Humanos , Radioisótopos do Iodo/normas , Tomografia por Emissão de Pósitrons , Controle de Qualidade , Radioquímica/instrumentação , Radioquímica/normas , Compostos Radiofarmacêuticos/normas , Iodeto de Sódio/isolamento & purificação , Iodeto de Sódio/normas
14.
Carbohydr Polym ; 195: 631-641, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29805021

RESUMO

In this study, chitosan based microbeads containing Ungeremine, an antimicrobial alkaloid particularly active against Penicillium roqueforti, a filamentous fungus responsible of the bakery products deterioration, were prepared by external gelation by using sodium tripolyphosphate (TPP) as crosslinking agent. The stability of the beads, as well as the loading efficiency of the bioactive molecule, were assessed at different pH and TPP concentrations resulting particularly enhanced at low pH. All the microbeads evidenced antimicrobial activity against Penicillium roqueforti. The release kinetics of Ungeremine was tailored by opportunely modulating pH and TPP concentrations. Morphological analysis evidenced the improvement of the structural crosslinking density of microbeads including Ungeremine and spectroscopic analysis emphasized the active participation of Ungeremine to the crosslinking process occurring between chitosan and TPP. Finally, thermogravimetric analysis confirmed the increasing of free volume in three-dimensional networks and their liability to thermal degradation.

15.
Int J Biol Macromol ; 115: 727-736, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29702173

RESUMO

Lignocellulose from agro-food biowaste represents a valuable source of cost-effective structural fillers for wholly renewable polymer composites. In this work, pecan (Carya illinoinensis) nutshell (NS) fiber and its structural components, holocellulose (HC) and acid insoluble lignin (AIL), were isolated, characterized and used as reinforcing fillers to manufacture poly(lactic acid) (PLA) based biocomposites. Thermal, morphological and mechanical properties of the prepared materials were analyzed. NS and HC acted as heterogeneous nucleating agents, potentially able to control PLA physical aging. Moreover, they significantly enhanced the viscoelastic response of PLA, mainly restricting the melt molecular mobility due to hydrodynamic effects and the formation of a three-dimensional particulate network. Flexural tests demonstrated that HC induced a 25% increase in modulus compared to the plain polymer. AIL, conversely, conferred higher ductility to the PLA matrix producing an increase in stress and strain at break of 55% and 65%, respectively. Finally, all the biocomposites showed lower resilience with respect to plain PLA due to the lack of chemical adhesion between filler and matrix. These results emphasize the potential of NS as a source of reinforcing filler in polymer-based biocomposites.


Assuntos
Carya/química , Lignina/química , Poliésteres/química , Fenômenos Mecânicos , Reologia , Temperatura
16.
Food Chem ; 258: 104-110, 2018 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-29655710

RESUMO

In this paper, a novel and sustainable process for the fruit dehydration was described. Specifically, edible coatings based on pectin and honey were prepared and used as dehydrating and antimicrobial agents of cut fruit samples, in this way promoting the fruit preservation from irreversible deteriorative processes. Pectin-honey coating was tested on apple, cantaloupe melon, mango and pineapple. The analysis were performed also on uncoated dehydrated fruits (control). The coated fruit evidenced enhanced dehydration percentage, enriched polyphenol and vitamin C contents, improved antioxidant activity and volatile molecules profile. Moreover, the antimicrobial activity against Pseudomonas and Escherichia coli was assessed. Finally, morphological analysis performed on fruit fractured surface, highlighted the formation of a non-sticky and homogeneous thin layer. These outcomes suggested that the novel fruit dehydration process, performed by using pectin-honey coating, was able to both preserve the safety and quality of dehydrated fruits, and enhance their authenticity and naturalness.


Assuntos
Conservantes de Alimentos/química , Frutas/química , Mel/análise , Pectinas/química , Ácido Ascórbico/química , Escherichia coli/efeitos dos fármacos , Conservantes de Alimentos/farmacologia , Malus/química , Malus/microbiologia , Mangifera/química , Mangifera/microbiologia , Polifenóis/química , Pseudomonas/efeitos dos fármacos
17.
Eur J Pharm Sci ; 111: 177-185, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28966100

RESUMO

Polymeric nanoparticles (NPs) of poly(ε-caprolactone) (PCL) covered with a hydrophilic poly(ethylene glycol) (PEG) shell are usually prepared from diblock PEG-PCL copolymers through different techniques. Furthermore PEG, NPs can be decorated with targeting ligands to accumulate in specific cell lines. However, the density and conformation of PEG on the surface and its impact on the exposition of small targeting ligands has been poorly considered so far although this has a huge impact on biological behaviour. Here, we focus on PEG-PCL NPs and their folate-targeted version to encourage accumulation in cancer cells overexpressing folate receptor α. NPs were prepared with mixtures of PEG-PCL with different PEG length (short 1.0kDa, long 2.0kDa,) and a folate-functionalized PEG-PCL (PEG 1.5kDa) by the widely employed solvent displacement method. In depth characterization of NPs surface by 1H NMR, fluorescence and photon correlation spectroscopy evidenced a PEGylation extent below 7% with PEG in a mushroom conformation and the presence of folate more exposed to water pool in the case of copolymer with short PEG. NPs with short PEG adsorbed HSA forming a soft corona without aggregating. Although limited, PEGylation overall reduced NPs uptake in human macrophages. Uptake of NPs exposing folate prepared with short PEG was higher in KB cells (FR+) than in A549 (FR-), occurred via FR-receptor and involved lipid rafts-dependent endocytosis. In conclusion, the present results demonstrate that PEG length critically affects protein interaction and folate exposition with a logical impact on receptor-mediated cell uptake. Our study highlights that the too simplistic view suggesting that PEG-PCL gives PEG-coated NPs needs to be re-examined in the light of actual surface properties, which should always be considered case-by-case.


Assuntos
Ácido Fólico/análogos & derivados , Nanopartículas/química , Poliésteres/química , Polietilenoglicóis/química , Polímeros/química , Portadores de Fármacos , Ácido Fólico/química , Humanos , Macrófagos/química , Macrófagos/fisiologia , Estrutura Molecular , Propriedades de Superfície
18.
Carbohydr Polym ; 157: 981-990, 2017 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-27988017

RESUMO

In this study, pectin based films including different amounts of sodium alginate were prepared by casting method. All the films, with and without polyglycerol as plasticizer, were crosslinked with zinc ions in order to extend their potential functionality. The development of junction points, occurring during the crosslinking process with zinc ions, induced the increasing of free volume with following changing in chemico-physical properties of films. The inclusion of alginate in pectin based formulations improved the strength of zinc ions crosslinking network, whereas the addition of polyglycerol significantly improved mechanical performance. Finally, zinc-crosslinked films evidenced antimicrobial activity against the most common exploited pathogens: Staphylococcus Aureus, Escherichia Coli and Candida Albicans. These results suggest that zinc-crosslinked based films can be exploitable as novel bio-active biomaterials for protection and disinfection of medical devices.


Assuntos
Alginatos/química , Anti-Infecciosos/química , Pectinas/química , Candida albicans , Escherichia coli , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Staphylococcus aureus
19.
Carbohydr Polym ; 147: 16-27, 2016 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-27178904

RESUMO

The use of a modified poly(ε-caprolactone) (gPCL) to enhance polymer miscibility in films based on thermoplastic starch (S) and poly(ε-caprolactone) is reported. PCL was functionalized by grafting with maleic anyhdride (MA) and/or glycidyl methacrylate (GMA) by reactive blending in a batch mixer. gPCL based materials were analysed in terms of their grafting degree, structural and thermal properties. Blends based on starch and PCL (wt. ratio 80:20) with including gPCL (0, 2.5 and 5wt.%), as a compatibilizer, were obtained by extrusion and compression moulding, and their structural, thermal, mechanical and barrier properties were investigated. Blends containing gPCL evidenced better interfacial adhesion between starch and PCL domains, as deduced from both structural (XRD, FTIR, SEM) and bulk properties (DSC, TGA). Moreover, grafted PCL-based compatibilizers greatly improved functional properties of S-PCL blend films, as pointed out from mechanical performance and higher barrier properties, valuable to meet the food packaging requirements.


Assuntos
Embalagem de Alimentos , Poliésteres/química , Amido/química , Poliésteres/metabolismo , Amido/metabolismo
20.
J Exp Clin Cancer Res ; 34: 89, 2015 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-26303220

RESUMO

BACKGROUND: When a patient concomitantly uses two or more drugs, a drug-drug interaction (DDI) can possibly occur, potentially leading to an increased or decreased clinical effect of a given treatment. Cancer patients are at high risk of such interactions because they commonly receive multiple medications. Moreover, most cancer patients are elderly and require additional medications for comorbidities. Aim of this preliminary observational study was to evaluate the incidence of well known and established DDIs in a cohort of cancer outpatients undergoing multiple treatments. METHODS: Anamnestic and clinical data were collected for 64 adult patients in the ambulatory setting with malignant solid tumors who were receiving systemic anticancer treatment. Patients also declared all drugs prescribed by other specialists or self-taken in the previous 2 weeks. DDIs were divided into two different groups: 'neoplastic DDIs' (NDDIs), involving antitumoral drugs, and 'not neoplastic DDIs' (nDDIs), involving all other classes of drugs. The severity of DDIs was classified as major, moderate and minor, according to the 'Institute for Pharmacological Research Mario Negri' definition. RESULTS: About 34 % of cancer outpatients within our cohort were prescribed/assumed interacting drug combinations. The most frequent major NDDIs involved the anticoagulant warfarin (33 % of total NDDIs) that, in association with tamoxifen, or capecitabine and paclitaxel, increased the risk of haemorrhage. About 60 % of nDDIs involved acetylsalicylic acid. CONCLUSIONS: Overall, 16 % of DDIs were related to an A-level strength of recommendation to be avoided. The lack of effective communication among specialists and patients might have a role in determining therapeutic errors. Our pilot study, although limited by a small cohort size, highlights the urgent need of implementing the clinical management of cancer outpatients with new strategies to prevent or minimize potential harmful DDIs.


Assuntos
Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico , Idoso , Antineoplásicos/uso terapêutico , Interações Medicamentosas , Feminino , Humanos , Masculino , Projetos Piloto
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