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Rapid and complete wound healing is a clinical emergency, mainly in pathological conditions such as Type 2 Diabetes mellitus. Many therapeutic tools are not resolutive, and the research for a more efficient remedial remains a challenge. Wound dressings play an essential role in diabetic wound healing. In particular, biocompatible hydrogels represent the most attractive wound dressings due to their ability to retain moisture as well as ability to act as a barrier against bacteria. In the last years, different functionalized hydrogels have been proposed as wound dressing materials, showing encouraging outcomes with great benefits in the healing of the diabetic wounds. Specifically, because of their excellent biocompatibility and biodegradability, natural bioactive compounds, as well as biomacromolecules such as polysaccharides and protein, are usually employed in the biomedical field. In this review, readers can find the main discoveries regarding the employment of naturally occurring compounds and biopolymers as wound healing promoters with antibacterial activity. The emerging approaches and engineered devices for effective wound care in diabetic patients are reported and deeply investigated. [ABSTRACT FROM AUTHOR]

Summary: An innovative functional food with symbiotic and functional potential was produced by combining probiotic milk kefir, and white grape‐seed pomace obtained by UAE (ultrasound‐assisted extraction) rich in catechin and glycosylated flavonoids. The milk kefir was fortified by adding, after 24 h of fermentation, a polymer of inulin grafted with seed extract. The inulin/grape extract‐enriched polymer showed a higher antioxidant profile (P < 0.05). Simulated in vitro digestion demonstrated that 50 g of the kefir product would result in the delivery of antioxidants equivalent to 300 mg of ascorbic acid. The integrity of the intestinal barrier functions was not compromised by kefir treatments (at 10 μg mL‐1). [ABSTRACT FROM AUTHOR]

Summary: Olive pomaces from Southern Italy autochthonous cultivars (Carolea, Nocellara and Roggianella) were eco‐friendly extracted to reach value‐added ingredients for the production of fortified pear beverages. Chemical composition of the extracts was carried out by 1H‐NMR analysis, while antioxidant features were in vitro evaluated. The extracts displayed remarkable scavenger properties against DPPH (IC50 values in the range 0.051–0.171 mg mL−1) and ABTS (IC50 values in the range 0.035–0.047 mg mL−1) radical species. Reactive species in the extracts and inulin chains were involved in an eco‐friendly radical process by grafting reaction to obtain macromolecular conjugates with outstanding antioxidant features, in terms of both antioxidant and scavenging performances, representing an attractive source in the design of functional foods. In this context, the conjugates were employed to enrich pear juice, to achieve reinforced beverages displaying remarkable antioxidant properties in comparison with its non‐functional counterparts, as well as its maintenance over time (20 days). [ABSTRACT FROM AUTHOR]

Nowadays, the treatment of infections produced by multidrug-resistant bacteria expects as a last resort the employment of polymyxins, a potent class of peptide antibiotics. 33396760 7 Stokniene J., Powell L.C., Aarstad O.A., Aachmann F.L., Rye P.D., Hill K.E., David T.W., Ferguson E.L. Bi-functional alginate oligosaccharide-polymyxin conjugates for improved treatment of multidrug-resistant gram-negative bacterial infections. Alternatively, a low-molecular-weight alginate oligosaccharide, able to inhibit bacterial growth, adherence and biofilm development, and which potentiates the activity of antibiotics against Gram-negative multidrug-resistant pathogens, was proposed to create a bi-functional antibiotic polymer [[7]]. Ubiquitous microorganisms such as bacteria, viruses, algae, and fungi induce several infectious diseases, representing crucial health challenges worldwide, due to increased antimicrobial resistance, high antimicrobial cost and adverse effects. [Extracted from the article]

Kefir is a symbiotic microbial blend of lactic acid bacteria, yeast, and acetic acid bacteria anchored to a polysaccharide matrix, endowing remarkable health benefits. The increase in the number of lactose intolerant, vegan and vegetarian consumers, led, in recent years, to develop fruit or vegetable-based healthy formulas. This review has been conceived to be a complete collection of different classes of non-dairy kefir products. Fruit or vegetable-based are used as substrates for milk or water kefir grains fermentation. The microbiological, chemical-physical, technological, and sensory aspects were discussed for each formulation. Moreover, when available, other potential health benefits were reported and discussed. • Alternative substrates for kefir fermentation were analysed and discussed. • Non-dairy kefir beverages show different features compared to milk-based product. • Like traditional one these products are rich in probiotic microorganisms. • Fruit or vegetable-based fermented drink possess antioxidant activity. • Grains can be used for multiple fermentations reducing production cost. [ABSTRACT FROM AUTHOR]

Cotton gauze was inserted into a hydrogel network composed of acrylamide, sodium methacrylate, and polyethylene glycol dimethacrylate to fabricate an electroresponsive delivery system for wound dressing. The composite was characterized by swelling measurements, showing that shrinking or swelling depend on the applied voltage. The release profile of incorporated diclofenac sodium salt shows the possibility to modulate the kinetics by changes in the amplitude and duration of applied electric pulses. Mathematical models allow a characterization of release profiles, which are slower when an external voltage of 6, 12, and 18 V is applied, and faster at 24 V. [ABSTRACT FROM AUTHOR]

Hydrogels sensitive to electric current are usually made of polyelectrolytes and undergo erosion, swelling, de-swelling or bending in the presence of an applied electric field. The electrical conductivity of many polymeric materials used for the fabrication of biomedical devices is not high enough to achieve an effective modulation of the functional properties, and thus, the incorporation of conducting materials (e.g., carbon nanotubes and nanographene oxide) was proposed as a valuable approach to overcome this limitation. By coupling the biological and chemical features of both natural and synthetic polymers with the favourable properties of carbon nanostructures (e.g., cellular uptake, electromagnetic and magnetic behaviour), it is possible to produce highly versatile and effective nanocomposite materials. In the present review, the recent advances in the synthesis and biomedical applications of electro-responsive nanocomposite hydrogels are discussed. [ABSTRACT FROM AUTHOR]

With the aim to modulate the flavonoid antioxidant properties, catechin and quercetin were covalently inserted into hydrogel networks by free radical grafting procedure. The effective conjugation of both flavonoids into the polymer chains was checked by FT-IR analyses. Water uptake measurements and calorimetric analyses proved the pH- and thermo-responsiveness. The effect of temperature on antioxidant properties were evaluated as scavenging ability and redox performance, while the determination of the ability to preserve folic acid from UV degradation proved the pH responsiveness. Data show that the matrices are more effective in the swollen than in the shrunken state. [ABSTRACT FROM PUBLISHER]

Hybrid materials with enhanced antibacterial activity were prepared by incorporation of carbon nanotubes within gelatin-fluoroquinolones bioconjugates. Gelatin bioconjugates were characterized by UV-Vis, FT-IR, and calorimetric analyses, nanohybrids by morphological analyses. Biocompatibility was evaluated on human mesenchymal stem cells, and antibacterial performance againstKlebsiella pneumoniaeandEscherichia coli. Minimun inhibitory concentrations from 0.025 to 0.05 µg mL−1and from 0.025 to 0.10 µg mL−1, and MBC from 0.025 to 0.10 µg mL−1and from 0.05 to 0.20 µg mL−1were detected forEscherichia coliandKlebsiella pneumoniae, respectively, showing that nanotubes increase antimicrobial activity comparing to both free and gelatin-conjugated drugs. [ABSTRACT FROM AUTHOR]

Abstract: This study has the goal to evaluate the stability of B complex vitamins, loaded into catechin-based crosslinked hydrogels, in aqueous medium at accelerated conditions of oxidative stress. The formulations were prepared by coupling polyacrylic acid with catechin in the presence of dicycloexylcarbodiimide. Folic acid (FA) and Thiamine (TH) were chosen within the B complex vitamins because of the well-known oxidative degradation characteristics. The protective role of the hydrogels against the oxidation damage was monitored inducing oxidative stress, by means of UV irradiation and t-butyl hydroperoxide treatment for FA and TH, respectively. The characterization of the hydrogels was obtained by morphological, calorimetric, FT-IR analyses, antioxidant assays and evaluation of the swelling behavior in aqueous media at different pH. The experimental results confirmed the suitability of the hydrogels as pH-responsive devices, furthermore the presence of oxidative condition proved the protective effect of the hydrogels. Catechin-based polymers gave a pronounced improvement in the stability of vitamins compared to hydrogels prepared by the coupling reaction of polyacrylic acid in the presence of 1,6-hexandiol. Under oxidative conditions, FA and TH were preserved by 96% and 60% respectively. [Copyright &y& Elsevier]

Site-Specific release of active molecules with antimicrobial activity spurred the interest in the development of innovative polymeric nanocarriers. In the preparation of polymeric devices, nanotechnologies usually overcome the inconvenience frequently related to other synthetic strategies. High performing nanocarriers were synthesized using a wide range of starting polymer structures, with tailored features and great chemical versatility. Over the last decade, many antimicrobial substances originating from plants, herbs, and agro-food waste by-products were deeply investigated, significantly catching the interest of the scientific community. In this review, the most innovative strategies to synthesize nanodevices able to release antimicrobial natural extracts were discussed. In this regard, the properties and structure of the starting polymers, either synthetic or natural, as well as the antimicrobial activity of the biomolecules were deeply investigated, outlining the right combination able to inhibit pathogens in specific biological compartments. [ABSTRACT FROM AUTHOR]

In this Special Issue, two articles were devoted to exploiting the employment of polyvinyl alcohol in the developing of useful drug delivery tools. Polyvinyl alcohol is one of the most popular water-soluble, non-carcinogenic, biocompatible, biodegradable synthetic polymers, and is largely employed to prepare hydrogels useful as artificial organs, drug delivery devices, and wound dressings [[2]]. Additionally, Avila-Salas et al. crosslinked polyvinyl alcohol with different dicarboxylic acids to synthesize dressing hydrogels [[4]]. 9 Cirillo G., Curcio M., Spizzirri U.G., Vittorio O., Valli E., Farfalla A., Leggio A., Nicoletta F.P., Iemma F. Chitosan-quercetin bioconjugate as multi-functional component of antioxidants and dual-responsive hydrogel networks. [Extracted from the article]

The interest in injectable hydrogels for cancer treatment has been significantly growing over the last decade, due to the availability of a wide range of starting polymer structures with tailored features and high chemical versatility. Many research groups are working on the development of highly engineered injectable delivery vehicle systems suitable for combined chemo-and radio-therapy, as well as thermal and photo-thermal ablation, with the aim of finding out effective solutions to overcome the current obstacles of conventional therapeutic protocols. Within this work, we have reviewed and discussed the most recent injectable hydrogel systems, focusing on the structure and properties of the starting polymers, which are mainly classified into natural or synthetic sources. Moreover, mapping the research landscape of the fabrication strategies, the main outcome of each system is discussed in light of possible clinical applications. [ABSTRACT FROM AUTHOR]

Wound-healing delay is one of the major problems of type 2 diabetes, representing also a clinical emergency in non-healing chronic wounds. Natural antioxidants show interesting wound-healing properties, including those extracted from waste derived from olive oil production. Olive mill wastewater is one of the main by-products of the olive oil-making process, and it is rich in high-value secondary metabolites, mainly hydroxytyrosol. We proposed an eco-friendly extraction method, employing both ultrasound-assisted and Soxhlet techniques and ethanol as a solvent, to recover valuable molecules from Roggianella cv (Olea europea L.) olive mill wastewater, which was further entrapped in a pectin polymer via an enzymatic reaction using porcine pancreatic lipase. Pectin, in combination with other substances, promoted and accelerated wound healing and demonstrated good potential to produce a biomedical conjugate for wound treatment. The antioxidant activity of the extracts and conjugate were evaluated against lipophilic (IC50 equal to 0.152 mg mL−1) and hydrophilic (IC50 equal to 0.0371 mg mL−1) radical species as well as the in vitro cytotoxicity via NRU, h-CLAT, and a wound-healing scratch assay and assessment. The pectin conjugate did not exert hemolytic effects on the peripheral blood, demonstrating interesting wound-healing properties due to its ability to stimulate cell proliferation in a dose-dependent manner. [ABSTRACT FROM AUTHOR]

Electro-responsive hybrid hydrogels were synthesized by free radical polymerization using Gelatin-coated multi-walled carbon nanotubes as electro-conductive component, acrylamide and polyethylene glycol dimethacrylate as plasticizing and crosslinking monomer, respectively. Dynamic light scattering, Raman spectroscopy, scanning electron microscopy, resistivity measurement, cell viability assay, and evaluation of swelling degree upon application of an external voltage at 0, 12, 24, 36, and 48 V were performed as characterization tools. Composite materials were found to be highly versatile in modulating the drug delivery of neutral drugs (e.g. Curcumin) as a function of both nanotube content and voltage magnitude, with drug partition between carrier and releasing media being dependent on the balance between electrostatic attractive and repulsive forces and hydrogel swelling degree. Finally, suitable mathematical modelling were employed for the kinetic characterization of the release mechanism. The results allowed hypothesizing the use of hybrid for different therapeutic needs in wound healing treatment. [ABSTRACT FROM AUTHOR]

The use of biologics, polymers, silicon materials, carbon materials, and metals has been proposed for the preparation of innovative drug delivery devices. One of the most promising materials in this field are the carbon-nanotubes composites and hybrid materials coupling the advantages of polymers (biocompatibility and biodegradability) with those of carbon nanotubes (cellular uptake, stability, electromagnatic, and magnetic behavior). The applicability of polymer-carbon nanotubes composites in drug delivery, with particular attention to the controlled release by composites hydrogel, is being extensively investigated in the present review. [ABSTRACT FROM AUTHOR]

Thermal and dual stimuli-responsive microspheres (pH and temperature) were prepared by free radical polymerization of methacrylate bovine serum albumin (BSA-MA) as cross-linker and sodium methacrylate (NaMA) and/or N-isopropylacrylamide (NIPAAm), as hydrophilic/pH-sensitive and thermo-responsive monomers, respectively. Microgels were characterized by infrared spectroscopy, morphological analysis, particle size distribution and determination of swelling properties. The network density and the shape of the microgels were found to depend on the concentration of the reactive species in the polymerization feed. Thermal analyses were performed to determine lower critical solution temperature values, which become close to the body temperature by increasing the content of the hydrophilic moieties in the network. In order to test the preformed materials as drug carriers, in vitro release studies of Diclofenac diethyl ammonium salt were performed. For all the co-polymers, a predominant drug release in the collapsed state was observed, while below the microgel transition temperature, a drug release through the swollen network occurs. The data recorded during the release tests demonstrated that the pH of the surrounding environment influences the drug release more than the temperature of the imbibing medium. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to investigate the possibility to synthesize new chelating polymeric microspheres owing immobilized biocompatible agent as chelating functional groups and to evaluate their performance in metal ions removal from aqueous solution. The microparticles were synthesized via precipitation polymerization of 4-O-(4-vinylbenzyl)-myo-inositol 1,3,5-orthoformate with ethylene glycol dimethacrylate (EGDMA) and subsequent exhaustive phosphorylation of myo-inositol groups using phosphoric acid. Spherical geometry with monodisperse nature of the polymeric microparticles was confirmed by scanning electron micrographs (SEM) and dimensional analysis. A large surface area of the microspheres provided a maximum interaction of metal ions and the chelating functional groups on the surface. Absorption capacity of the beads for the selected metal ions, i.e., Cu(II), Ni(II), Fe(III), was investigated in detail in aqueous solution at pH 5.0 utilizing UV/Vis spectroscopy. This study showed that the macromolecular systems are very effective in chelating these metal ions and the affinity order of the microbeads toward metal ions is: Fe(III)>Ni(II)>Cu(II). The chelating beads can be easily regenerated by 1.0M HNO3 with high effectiveness. These features make the synthesized beads a potential candidate for metal ions removal at high capacity. [Copyright &y& Elsevier]

Purpose: Solid tumors exhibit an altered redox state in comparison with normal tissues due to tumor hypoxia, lower pH, and elevated levels of the tripeptide glutathione. This study describes the preparation of functional redox-responsive nanoparticles proposed as delivery vehicle of Doxorubicin in adrenocortical cancer in vitro. Methods: Curcumin and Lipoic acid were conjugated to Human Serum Albumin and nanoparticle systems were prepared via a modified desolvation method. Scanning electron microscopy, Fourier transmission IR, dynamic light scattering and differential scanning calorimetry analyses were used to characterize the nanoparticles. Balb3T3 and H295R were used as in vitro models of health and cancer cells, respectively. Results: Nanoparticles with a spherical shape and a mean diameter of 70 nm were observed, increasing up to ten-folds upon exposure to glutathione 10 mM. Redox responsive Doxorubicin release was recorded, with loaded nanoparticles significantly enhancing the drug cytotoxicity against H295R adrenocortical tumor cells. Cell uptake experiments revealed a rapid and efficient internalization of the nanoparticles. Conclusions: A valuable tools to actively improve the in vitro anticancer activity of Doxorubicin against adrenocortical cancer was proposed. The effectiveness of the delivery vehicle is related to the presence of both Lipoic acid and Curcumin moieties, enhancing the glutathione responsivity, and the drug cytotoxicity, respectively. [ABSTRACT FROM AUTHOR]

Multifunctional hydrogels based on chitosan–quercetin (CHITQ) conjugate are prepared by a thermo‐induced radical procedure in the presence of N‐isopropylacrylamide (NIPAAm), acrylamide (AAm), and N,N′‐methylenebis(acrylamide) (MEBA). At first, quercetin (Q) is grafted onto chitosan backbone with a functionalization degree of 275 mg of Q per gram of conjugate, as calculated by 1H‐NMR analyses to impart antioxidant properties to the polysaccharide. Then, a pH and temperature sensitive hydrogel was obtained by involving CHITQ and NIPAAm in the polymerization reaction. The accessibility of phenolic moieties is modified in response to the hydrogel swelling/deswelling, as confirmed by antioxidant tests performed at different temperatures. Dual stimuli‐responsive hydrogels are proposed for the delivery of caffeine as model drug. The release profiles of caffeine depict a system particularly performing as on/off device at acidic pH with excellent applicability prospects. [ABSTRACT FROM AUTHOR]

Redox-responsive nanoparticles were synthesized by desolvation of bovine serum albumin followed by disulfide-bond crosslinking with N , N ʹ-Bis (acryloyl) cystamine. Dynamic light scattering and transmission electron microscopy studies revealed spherical nanoparticles (mean diameter: 83 nm, polydispersity index: 0.3) that were glutathione-responsive. Confocal microscopy revealed rapid, efficient internalization of the nanoparticles by Daoy medulloblastoma cells and healthy controls (HaCaT keratinocytes). Cisplatin-loaded nanoparticles with drug:carrier ratios of 5%, 10%, and 20% were tested in both cell lines. The formulation with the highest drug:carrier ratio reduced Daoy and HaCaT cell viability with IC 50 values of 6.19 and 11.17 μg mL −1 , respectively. The differential cytotoxicity reflects the cancer cells’ higher glutathione content, which triggers more extensive disruption of the disulfide bond-mediated intra-particle cross-links, decreasing particle stability and increasing their cisplatin release. These findings support continuing efforts to improve the safety and efficacy of antineoplastic drug therapy for pediatric brain tumors using selective nanoparticle-based drug delivery systems. [ABSTRACT FROM AUTHOR]

Hybrid hydrogel films able to modulate the release of anionic species, ketoprofen (Ket) and bovine serum albumin (BSA), as a function of their molecular size are prepared by UV-induced polymerization of methacrylated gelatin in the presence of oxidized multiwalled carbon nanotubes (MWNT_COOH). The dual-stimuli responsive composites can modulate the release in response to the variation of temperature and the application of an external voltage. Drug release profiles, analyzed by mathematical models, show that different temperatures (25 and 45 °C) and applied voltages (0 and 36 V) have a different effect on the release of the two therapeutics. Ket release is enhanced at 45 °C (77% vs 22% at 25 °C) with the maximum value recorded when 36 V is applied (94%). An increase in the amount of released BSA is recorded at 45 °C (96% vs 50% at 25 °C), while the application of the external voltage reduces this value (39%). [ABSTRACT FROM AUTHOR]

Dextran-catechin conjugate with high functionalization degree is synthesized by using a fully green process based on the chemistry of laccase immobilized on hydrogel film. By UV-induced radical polymerization, the enzyme is immobilized into acrylate hydrogel film resulting in a highly performing biocatalyst (residual catalytic activity of 60% upon immobilization). ¹H-NMR studies of dextran-catechin conjugate allow the elucidation of the reaction mechanism and the assessment of the functionalization degree (128 mg of catechin per gram of conjugate). Cell viability studies performed in neuroblastoma cells clearly prove the anticancer potential of the conjugate (IC50 value of 17.03 µg mL-1) while being well tolerated by nonmalignant cells. The efficiency of this conjugate is found to be similar to dextran-catechin, previously prepared by free radical reaction. This novel green approach of synthesis for dextran-catechin opens new perspectives for the environmentally sustainable development of novel natural derived drugs to treat neuroblastoma and other cancers. [ABSTRACT FROM AUTHOR]

In recent years, antioxidants have gained great importance because of their potential use in food, pharmaceutical, and cosmetic industries. This interest is rooted in the cumulative evidence connecting active oxygen and free radicals with numerous human degenerative disorders, such as cardiovascular diseases, cancer, aging, and atherosclerosis. Polyphenols are the major class of antioxidant able to reduce the oxidative damages of lipids, proteins, enzymes, carbohydrates, and DNA in living cells and tissues. Among the realm of polyphenol compounds, polyphenol conjugates have been proposed as innovative materials which, by combining the advantageous properties of both the components, can increase the efficiency of antioxidants and their range of application in nutritional and biomedical fields. This work is an overview of the different class of polyphenol conjugates, which will be analyzed in terms of nutritional and biological properties, showing how these bio-conjugates will positively affect the human health. [ABSTRACT FROM AUTHOR]

Monodispersed polymersomes based on a hydrophobically-modified protein with dimensional range between 154 and 254 nm were prepared employing a water addition/solvent evaporation method. Gelatin hydrolyzate and PEG 40 -stearate, acting as hydrophilic and hydrophobic blocks, respectively, underwent radical coupling and three materials with different hydrophilic/lipophilic ratio were obtained by varying the amount of PEG 40 -stearate in the reaction feed. Critical aggregation concentrations of each amphiphilic polymer were found ranged from 3.9 to 10.2 μg mL −1 , with lower values recorded for conjugate with lower hydrophilic/lipophilic ratio. Anticancer drug methotrexate was loaded into the vesicular systems with efficiency strictly dependent on the gelatin hydrolyzate content and the in vitro releasing profile assessed and analyzed by suitable mathematical models. To prove the applicability of the proposed delivery vehicle, the biocompatibility properties were assessed in normal human lung fibroblasts cells MRC-5, while the anticancer efficiency was tested on H1299 lung cancer cells, proving that the drug encapsulation into the polymersomes dramatically reduced the cytotoxicity on healthy cells while preserving its efficiency in killing cancer cells. [ABSTRACT FROM AUTHOR]

A new approach for the synthesis of hydrogel films with thermo-sensitive enzymatic activity is reported. Pepsin (PEP) was covalently immobilized on thermo-responsive hydrogels by radical polymerization in the presence of N-isopropylacrylamide and poly-(ethylene glycol) dimethacrylate 750, acting as functional monomer and crosslinking agent, respectively. Hydrogels showing lower critical solution temperatures between 32.9 and 36.1 °C were synthesized by UV-irradiation of reaction batches differing in the PEP/monomers ratio. The derivatization degree of the hydrogels was expressed as mg of PEP per gram of matrix and found to be in the range of 6 to 11% as assessed by Lowry method. Scanning electron microscopy analysis and water affinity evaluation allowed to highlight the porous morphology and thermo-responsivity of hydrogels as a function of temperature. Using bovine serum albumin as a substrate, kinetics parameters were determined by Lineweaver–Burk plots and the catalyst efficiency evaluated. The influence of temperature on enzyme activity, as well as the thermal stability and reusability of devices, were also investigated. [ABSTRACT FROM AUTHOR]

Abstract: A new hybrid material made of gelatin, catechin and carbon nanotubes was prepared by the non-covalent incorporation of carbon nanotubes (CNTs) into a gelatin–catechin covalent conjugate. The composite materials was tested by means of determination of the dispersion stability in water and the functionalization degree was assessed by the Folin–Ciocalteu method, finding a 0.9mg of CT/g of protein conjugate. Subsequently, the complete retention of the antioxidant properties of the flavonoid after incorporation into the composite was proved by DPPH and ABTS assays and IC50 values of 5.74mgmL−1 and 0.39mgmL−1 were recorded. The presence of CNT into the materials did not interfere with the scavenging activities of the catechin. Finally, the anticancer activity on HeLa cancer cells was evaluated and a considerable increase in the therapeutic activity of the flavonoid was recorded moving from the free to the conjugated form in the presence of CNT, while in absence of CNT a reduction of the efficiency was observed. [Copyright &y& Elsevier]

Biogenic amines (BAs) are detrimental to health and the consumption of food containing high concentrations of these compounds may cause toxic reactions. In particular, cases of tyramine intoxication have occurred subsequent to the consumption of cheese and the term “cheese reaction” has been coined to refer to it. The main pre-requisites for the presence of BAs in foods include: availability of free amino acids, the presence of microorganisms producing BA enzymes (mainly from raw materials and/or added starter cultures), conditions allowing their growth (particularly temperature, pH), as well as conditions affecting the enzyme production and activity (particularly low pH). The main technological aspects affecting aminogenesis in cheese are the presence of micro-organisms, their proteolytic and decarboxylase activities, ripening time, ripening temperature, pH and NaCl concentration. Moreover secondary parameters such as post-ripening processes and packaging can affect the accumulation of BAs as well. High temperature, high pH, low salt content, prolonged ageing and air packaging seem to accelerate the amino acid accumulation while the effect of grating seem to be mostly related with microbiological contamination, both aspects supporting the BAs increase. [ABSTRACT FROM AUTHOR]

Abstract: A new Molecularly Imprinted Solid Phase Extraction (MISPE) protocol was developed for the selective extraction and purification of glycyrrhizic acid (GL) from liquorice roots. Non-covalent MIP were synthesized using methacrylic acid (MAA), 2-(dimethylamino)ethyl methacrilate (DMAEM) or 2-hydroxyethylmetacrylate (HEMA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent. After the evaluation of the selectivity of the GL imprinted polymers, the performance of these materials as Solid Phase Extraction (SPE) sorbents was investigated. MIP having HEMA as functional monomer were found to be able to selectively extract almost 80% of GL content in liquorice roots. The proposed MISPE-HPLC procedure has good precision, thus it can be successfully used for the purification of GL from natural sources. [ABSTRACT FROM AUTHOR]

Objectives To prove the possibility of covalently functionalizing multi-walled carbon nanotubes (CNTs) by free radical grafting of gallic acid on their surface with the subsequent synthesis of materials with improved biological properties evaluated by specific in-vitro assays. Methods Antioxidant CNTs were synthesized by radical grafting of gallic acid onto pristine CNTs. The synthesis of carbon nanotubes was carried out in a fixed-bed reactor and, after the removal of the amorphous carbon, the grafting process was performed. The obtained materials were characterized by fluorescence and Fourier transform infrared spectroscopy (FT-IR) analyses. After assessment of the biocompatibility and determination of the disposable phenolic group content, the antioxidant properties were evaluated in terms of total antioxidant activity and scavenger ability against 2,2′-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl and peroxyl radicals. Finally the inhibition activity on acetylcholinesterase was evaluated. Key findings The covalent fuctionalization of CNTs with gallic acid was confirmed and the amount of gallic acid bound per g of CNTs was found to be 2.1 ± 0.2 mg. Good antioxidant and scavenging properties were recorded in the functionalized CNTs, which were found to be able to inhibit the acetylcholinesterase with potential improved activity for biomedical and pharmaceutical applications. Conclusions For the first time, a free radical grafting procedure was proposed as a synthetic approach for the covalent functionalization of CNTs with an antioxidant polyphenol. [ABSTRACT FROM AUTHOR]

Objectives The aim was to synthesize molecularly imprinted polymers (MIPs) with high recognition properties towards glycyrrhizic acid and to evaluate the performance of these materials to act as base excipients in glycyrrhizic acid sustained release in gastrointestinal simulating fluids. Methods MIPs were synthesized using methacrylic acid (MAA) as acidic, 2-(dimethylamino)ethyl methacrylate (DMAEMA) as basic, and 2-hydroxyethylmethacrylate (HEMA) as neutral functional monomers, while ethylene glycol dimethacrylate (EGDMA) was chosen as a crosslinking agent. The imprinting effect was evaluated by binding experiments using glycyrrhizic acid and glycyrrhetic acid (analogue molecule) solutions and in-vitro release studies were performed in gastrointestinal simulating fluids. Key findings Good recognition and selectivity properties were found in all the synthesized materials in both ethanol and ethanol-water mixture. The release from non-imprinted polymers was indeed higher at acidic pH, while a slower release was observed in MIPs' case, because of the presence of imprinted cavities in the polymeric structure. The stronger capacity of MAA to interact by hydrogen bonds with the template makes MAA-containing MIPs the most effective materials in both rebinding and release experiments. ConclusionsThe release tests confirm the applicability of imprinted polymer for glycyrrhizic acid sustained release in gastrointestinal simulating fluids. [ABSTRACT FROM AUTHOR]

New Restricted Access Materials—Molecularly Imprinted Polymers (RAM-MIP) were synthesized by using caffeine (CAFF), methacrylic acid (MAA), divinyl benzene (DVB) and glycidil methacrylate (GMA) as model template, functional monomer, crosslinking agent and pro-hydrophilic co-monomer, respectively. Furthermore, a screening of the ratio of functional monomer to template was performed. After the preliminary characterizations of conventional MIP prepared in absence of GMA, different GMA amounts were inserted in the pre-polymerization feeds and different reactions conditions were tested for GMA epoxide ring opening. In particular, perchloric acid, ammonia, lactic acid, glycine and triethylene glycol were chosen for this purpose. In perchloric acid and ammonia cases, a further modification was performed by phosphorylation and methylation procedures, respectively. Imprinting efficiency of all the obtained materials was evaluated by binding experiments using caffeine and its analogue theophylline both in organic and in water media. The increased hydrophilic characteristics of RAM polymers by water absorption measurement and protein binding experiments were performed. [ABSTRACT FROM AUTHOR]

Abstract: A new restricted access materials combined to molecularly imprinted polymers (RAM-MIP) with hydrophilic external layer were prepared and their applicability in p-acetaminophenol (AMP) selective recognition and release was evaluated. Glycidilmethacrylate (GMA) was used as pro-hydrophilic co-monomer, and GMA epoxide ring opening with perchloric acid was performed for the hydrophilic modification of polymeric surface. Morphological and hydrophilic properties by scanning electron microscopy and water content measurement were determined and recognition and selectivity properties of RAM-MIP were compared to the unmodified MIP. With RAM-MIP, both hydrophobic non-specific interactions between template or its analogues and polymeric matrices, and bovine serum albumin absorption were drastically reduced. [Copyright &y& Elsevier]

Abstract: Sudan I is a synthetic azoic dye employed as an additive in foods, and in particularly in those containing chilli powders, because of his intense red–orange colour. Now European Community does not allow “Sudan I” as an additive in foods because of its demonstrated cancerogenity. Several methods were developed to detect the presence of this compound (HPLC, GC/MS). However when “Sudan I” is mixed just in traces in foods, very expensive instruments are necessary (LC/MS/MS) to reveal it. This study describes the synthesis of a molecularly imprinted polymers (MIPs) for solid phase extraction (MISPE) using Sudan I as template. This procedure allows to concentrate this compound in order to make it detectable by HPLC. Furthermore we investigated the ability of these MISPE cartridges to absorb selectively Sudan I from food matrices. Considerable differences in the interaction with “Sudan I” were observed when MIPs were used as stationary phase in SPE compared with the non imprinted polymers (NIPs). [Copyright &y& Elsevier]

In this work, novel polymeric mixed micelles from Pluronic F127 and Cremophor EL were investigated as drug delivery systems for Norfloxacin as model antibiotic drug. The optimal molar ratio of surfactants was determined, in order to decrease critical micellar concentration (CMC) and prepare carriers with minimal surfactant concentrations. The particle size, zeta potential, and encapsulation efficiency were determined for both pure and mixed micelles with selected composition. In vitro release kinetics of Norfloxacin from micelles show that the composition of surfactant mixture generates tunable extended release. The mixed micelles exhibit good biocompatibility against normal fibroblasts MRC-5 cells, while some cytotoxicity was found in all micellar systems at high concentrations. The influence of the surfactant components in the carrier on the antibacterial properties of Norfloxacin was investigated. The drug loaded mixed micellar formulation exhibit good activity against clinical isolated strains, compared with the CLSI recommended standard strains (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29213, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922). P. aeruginosa 5399 clinical strain shows low sensitivity to Norfloxacin in all tested micelle systems. The results suggest that Cremophor EL-Pluronic F127 mixed micelles can be considered as novel controlled release delivery systems for hydrophobic antimicrobial drugs. [ABSTRACT FROM AUTHOR]

Several epidemiological studies demonstrate that moderate (red) wine consumption may afford protection against cardiovascular diseases. Protection is ascribed to the biological activity of wine components, many of which, however, are discarded during winemaking. In vitro rat thoracic aorta rings contracted with phenylephrine or KCl were used to assess the vasorelaxant activity of extracts from wine pomaces (seeds and skins) of the Calabrian autochthonous grape variety Magliocco dolce (Arvino). NMR spectroscopy was used to ascertain their chemical composition. Data demonstrate that seed and skin, but not must, extracts are capable of relaxing vascular preparations in an endothelium-dependent manner, similarly to the red wine extract, due to the presence of comparable amounts of bioactive constituents. In rings pre-contracted with 20–30 mM KCl, only seed extracts showed a moderate relaxation. The most efficacious vasodilating extract (wine) showed a good antioxidant profile in both [(2,2-diphenyl-1-picrylhydrazyl)acid] radical (DPPH) and [2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid)] radical (ABTS) assays. In conclusion, winemaking from Magliocco dolce grape can provide potentially health-promoting by-products useful in cardiovascular disease management. [ABSTRACT FROM AUTHOR]

A hybrid system composed of multi-walled carbon nanotubes coated with chitosan was proposed as a pH-responsive carrier for the vectorization of methotrexate to lung cancer. The effective coating of the carbon nanostructure by chitosan, quantified (20% by weight) by thermogravimetric analysis, was assessed by combined scanning and transmission electron microscopy, and X-ray photoelectron spectroscopy (N1s signal), respectively. Furthermore, Raman spectroscopy was used to characterize the interaction between polysaccharide and carbon counterparts. Methotrexate was physically loaded onto the nanohybrid and the release profiles showed a pH-responsive behavior with higher and faster release in acidic (pH 5.0) vs. neutral (pH 7.4) environments. Empty nanoparticles were found to be highly biocompatible in either healthy (MRC-5) or cancerous (H1299) cells, with the nanocarrier being effective in reducing the drug toxicity on MRC-5 while enhancing the anticancer activity on H1299. [ABSTRACT FROM AUTHOR]