In vitro Antifungal Activity of Olive (Olea europaea) Leaf Extracts Loaded in Chitosan Nanoparticles.

Olive leaf extract is characterized by a high content of phenols and flavonoids (oleuropein, luteolin, and their derivatives). These compounds are defined as secondary metabolites and exert such as anti-inflammatory, antioxidant, and antimicrobial activities. We investigated the in vitro antifungal activity of two olive leaf extracts (named EF1 and EF2) against a Fusarium proliferatum (AACC0215) strain that causes diseases to many economically important plants and synthesizing diverse mycotoxins. In this work, we aimed to identify the most appropriate concentration between the tested two olive leaf extracts to develop a safe, stable and efficient drug delivery system. Qualitative and quantitative analyses of the two olive leaf extracts by (HPLC) were performed. Furthermore, we also evaluated the antifungal effects of the two leaf extracts when encapsulated in chitosan-tripolyphosphate nanoparticles. The major compound in both EF1 and EF2 was oleuropein, with 336 and 603 mg/g, respectively, however, high concentrations of flavonoid were also present. EF1 and EF2 showed a concentration depended effect on F. proliferatum (AACC0215) viability. Our results showed a great efficacy of EF1/nanoparticles at the higher concentration tested (12X) against the target species. In this case, we observed an inhibition rate to both germination and growth of 87.96 and 58.13%, respectively. We suggest that EF1 olive leaf extracts, as free or encapsulated in chitosan-tripolyphosphate nanoparticles, could be used as fungicides to control plant diseases. Finally, future application of these findings may allow to reduce the dosage of fungicides potentially harmful to human health.

Hemostatic gauze based on chitosan and hydroquinone: preparation, characterization and blood coagulation evaluation.

This work concerns on the preparation and performance evaluation of a new chitosan hydroquinone based gauze for hemostatic use. Chitosan and hydroquinone were firstly connected by etherification and then linked to the pre-carboxylate gauze. The functionalized material and the chitosan-hydroquinone ether were characterized by Fourier Transform Infrared (FT-IR) Spectroscopy and Differential Scanning Calorimetry (DSC). FT-IR results showed that an esterification occurred on carboxylic group of the gauze. The gauze functionalization degree was also evaluated by volumetric analysis. The ether hydroquinone content was obtained by the Folin test. Moreover, the linkage between hydroquinone and chitosan was confirmed by nuclear magnetic resonance (NMR). The hemostatic activity of functionalized gauze was evaluated by dynamic blood clotting assays. The obtained results showed that the prepared material can shorten the blood clotting time and induce the adhesion and activation of platelets. Finally, swelling characteristic of the new gauze was evaluated to confirm its high capacity to absorb the blood.

Albumin nanoparticles for glutathione-responsive release of cisplatin: New opportunities for medulloblastoma.

Redox-responsive nanoparticles were synthesized by desolvation of bovine serum albumin followed by disulfide-bond crosslinking with N, N'-Bis (acryloyl) cystamine. Dynamic light scattering and transmission electron microscopy studies revealed spherical nanoparticles (mean diameter: 83nm, 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 IC50 values of 6.19 and 11.17µgmL-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.

Spontaneous temperature-sensitive Pluronic(®) based niosomes: Triggered drug release using mild hyperthermia.

Inclusion of lipids or polymers with a transition temperature closer to physiological body temperature (40-42°C) is a strategy used in tumor therapy for more than 30 years, because it allows induction of drug release from delivery systems by mild hyperthermia. Unfortunately, most of these thermo-sensitive carriers are removed from circulation before completion of their function. Thus, novel multi-functional niosomes possessing spontaneous stealth and thermo-sensitive properties were developed from L64 Pluronic(®) and L64ox as its derivative, in presence or absence of cholesterol. The use of L64 both as amphiphilic constituent and thermo-sensitive molecule, gave the possibility to bypass the use of additional excipients and increased the system biocompatibility. Niosomes diameter ranged from 400 to 750nm and were long term stable. Calcein and 5-FU possess great affinity to niosomal matrices rich in PEO groups. Negative Z-potential values were attributed to the negative charges onto the niosomes surface and generally change according to the temperature. The in vitro drugs release studies were performed at 25°C, 37°C and 42°C, that are representative of certain conditions (storage, physiological condition and mild hyperthermia, respectively). Results showed that L64-based niosomes possess spontaneous thermo-sensitive properties: drugs releases were found to be more pronounced at 42°C. These early results are a promising first step for the development of multi-functional devices that combine several advantages such as stealth properties and temperature controllability at the desired location and time, for a more specific and efficient pharmacological therapy.

Extraction Efficiency of Different Solvents and LC-UV Determination of Biogenic Amines in Tea Leaves and Infusions.

Biogenic amines (BAs), that is, spermine, spermidine, putrescine, histamine, tyramine, ß-phenylethylamine, cadaverine, and serotonin, have been determined in several samples of tea leaves, tea infusions, and tea drinks by LC-UV method after derivatization with dansyl chloride. Different extraction solvents have been tested and TCA 5% showed better analytical performances in terms of linearity, recovery percentages, LOD, LOQ, and repeatability than HCl 0.1 M and HClO4 0.1 M and was finally exploited for the quantitative determination of BAs in all samples. In tea leaves total BAs concentration ranged from 2.23 µg g(-1) to 11.24 µg g(-1) and PUT (1.05-2.25 µg g(-1)) and SPD (1.01-1.95 µg g(-1)) were always present, while SER (nd-1.56 µg g(-1)), HIS (nd-2.44 µg g(-1)), and SPM (nd-1.64 µg g(-1)) were detected more rarely. CAD and PHE were determined in few samples at much lower concentrations while none of the samples contained TYR. Tea infusions showed the same trend with total BAs concentrations never exceeding 80.7 µg L(-1). Black teas showed higher amounts of BAs than green teas and organic and decaffeinated samples always contained much lower BAs levels than their conventional counterparts.

Further Evolution of Multifunctional Niosomes Based on Pluronic Surfactant: Dual Active Targeting and Drug Combination Properties.

The loading of chemotherapics into smart nanocarriers that simultaneously possess more than one useful property for specifically targeting a tumor site improves their therapeutic effectiveness, reducing their side effects. Hence, we proposed a combined approach for the treatment of human breast cancer (BC) consisting of the co-encapsulation of doxorubicin and curcumin or doxorubicin and quercetin into multifunctional niosomes, which results in prolonged blood circulation and an ability to spontaneously accumulate at the tumor site (passive target) and to recognize and bind the tumor cells through dual ligand-receptor interactions (active target). The drug-loaded vesicles showed high stability and good capability of loading doxorubicin and antioxidants alone or in combination. Their diameter was around 400 nm. The drugs released from the vesicles were found to be controlled and sustained for over 24 h, with a strong dependence on the co-presence of the loaded molecules. Transferrin and/or folic acid were conjugated on the external surface of the niosomes as ligands, considerably improving the cellular uptake into MCF-7 and MDA-MB-231 malignant cells when compared with the uptake of nonconjugated samples. In vitro evaluation of anticancer activity demonstrated the strong potential of niosomes loaded with a doxorubicin/curcumin combination as useful devices in breast tumor treatment. These features hold great promise for the development of multifunctional devices that combine several advantages such as biocompatibility, stealth properties, loading capability, and active targeting, moving toward the development of more specific and efficient carriers for personalized tumoral therapy.

Influence of packaging conditions on biogenic amines and fatty acids evolution during 15months storage of a typical spreadable salami ('Nduja).

The study evaluated the fatty acids and the biogenic amines (BAs) in 'Nduja of Spilinga stored in different packaging materials (i.e. natural casing under vacuum, glass jar, aluminum tube and OVTENE®) during 15months of shelf-life. Raw materials and pepper mixture were analysed as well. BAs concentrations increased with time, tyramine (TYR), putrescine (PUT) and cadaverine (CAD) were the most abundant. BAs in natural casing were always higher than those found in glass jar, aluminum tube and OVTENE®. Total fatty acids were characterized by higher level of unsaturated fatty acid that decreased with time (glass jar>natural casing under vacuum>aluminum tube>OVTENE®). The reduction of PUFA is the consequence of the increase of peroxides and carbonyls reacting with amino acids to form BAs. This was confirmed by Pearson's correlation matrices implying that lipid oxidation processes were in some way linked to the chemical production of BAs.

Novel microspheres based on triterpene saponins from the roots of Physospermum verticillatum (Waldst & Kit) (Apiaceae) for the improvement of gemcitabine release.

OBJECTIVES: This study concerns the preparation and characterization of microspheres based on a mixture of triterpene saponins, from Physospermum verticillatum (Waldst & Kit), as a carrier for the specific release of gemcitabine. METHODS: Triterpene saponins were derivatized with acrylic acid. The obtained polymerizable product was characterized by Fourier transform infrared to confirm the ester linkage. Then, spherical microparticles were prepared by suspension radical copolymerization and impregnated with gemcitabine. KEY FINDINGS: Microspheres exhibited a mean diameter of 2.7 µ. The swelling studies showed that particles swell most at pH 6.2, typical of the tumour pathology, than at pH 7.4, miming physiological conditions. The microspheres were loaded with gemcitabine (LE 72.2%). Their release profile showed an initial dot of around 24% and a further release for 24 h. CONCLUSIONS: This carrier could be potentially release the drug in the lung, as a function of different pHs between tumour cells and healthy, reducing the systemic drug toxicity, allowing the reduction of the doses number, increasing the drug half-life and eliminating the problems related to the fast clearance of gemcitabine administration.

Engineered Polymer-Based Nanomaterials for Diagnostic, Therapeutic and Theranostic Applications.

Nanomedicine can be defined as the medical application of molecular nanotechnology and it plays a key role and pharmaceutical research and development, especially related to cancer prevention, monitoring, diagnosis and treatment. In this context, nanomaterials are attracting significant research interest due to their abilities to stay in the blood for long time, accumulate in pathological sites including tumors or inflammatory areas via the enhanced permeability and retention (EPR) effect, and facilitate targeted delivery of specific therapeutic agents. In the last decades, considerable attention was attracted by the development of nano-sized carriers, based on natural or synthetic polymers, able to provide the controlled release of anticancer drugs in the aim to overcome the drawbacks associated to the conventional chemotherapy. Furthermore, when loaded with imaging agents, this kind of systems offers the opportunity to exploit optical or magnetic resonance imaging (MRI) in cancer diagnosis. Polymeric materials are characterized by several functionalities where both therapeutic and imaging components, and also targeting moieties, can be attached for simultaneous targeted therapy and imaging providing innovative platforms defined as theranostic agents with a great potential in monitoring and treatment of cancer.

Carbon Nanohybrids as Electro-Responsive Drug Delivery Systems.

Electro-responsive nanomaterials are usually made with polyelectrolytes able to undergo shrinkage or swelling by tuning on electrical fields. Nevertheless, the electrical conductivity of many polymeric materials used for the fabrication of release devices is not high enough to achieve an effective modulation of the drug release. The incorporation of conducting materials (e.g. carbon nanostructures) in polymeric networks has been proposed as a valuable strategy to overcome this limitation. In this regard, carbon nanotubes and graphene, by virtue of their unique chemical structures and attractive physiochemical properties, have been receiving exciting attention primarily in biology and medicine. By their incorporation into composite hydrogels, the biocompatibility and biodegradability of polymers can be merged with the favorable properties of carbon nanostructures, such as enhanced cellular uptake, electromagnetic, and magnetic behavior. The applicability of carbon hybrid materials to modulate release of therapeutics in response to an external current voltage, is being extensively investigated in the present review.

Polyphenol Conjugates and Human Health: A Perspective Review.

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.

Cromolyn as surface active drug (surfadrug): Effect of the self-association on diffusion and percutaneous permeation.

Cromolyn sodium, or disodium cromoglycate (CS), is a surface active drug: a pharmacologically active compound with an amphiphilic nature. At certain conditions it is able to self-associate in several kind of supramolecular aggregates. Since CS could play the role of both carrier and drug, bypassing the use of additional excipients and increasing the system biocompatibility, the effects of cromolyn self-aggregates on diffusion and percutaneous permeation across rabbit ear skin were investigated. Niosomes (vesicular systems, 0.5wt% of CS), monomeric and isotropic solutions (0.5 and 5wt% of CS), nematic (15wt% of CS) and hexagonal phases (30wt% of CS) were selected as supramolecular systems and tested as transdermal delivery systems. Results demonstrated that CS was able to form vesicular structures of about 500nm of diameter and this formulation gave the higher percutaneous permeation profile (systemic action), while isotropic solution and liquid crystals mesophases acted as slower release reservoir of drug on the skin surface (local action), as confirmed by diffusion coefficients. Diffusion rates through a synthetic membrane were dependent both on CS concentration present into the formulations and on its structural organization: maximum diffusion was noticed with isotropic solution, a lower amount of diffused cromolyn sodium was achieved by hexagonal phase. Consequently, CS appears as a versatile surfadrug as, depending on the disease degree, it is possible to modulate its permeation profile by choosing the most appropriate formulation.

Preparation, characterization and in vitro activities evaluation of solid lipid nanoparticles based on PEG-40 stearate for antifungal drugs vaginal delivery.

The present article reports the preparation, characterization and performance evaluation of solid lipid nanoparticles (SLNs) based on polyoxyethylene-40 stearate (PEG-40 stearate) for the administration of antifungal agents such as ketoconazole and clotrimazole. These nanoparticles could be useful in the treatment of vaginal infections sustained by Candida albicans. In particular, PEG-40 stearate was made to react with acryloyl chloride in order to introduce an easily polymerizable moiety for the creation of a second shell and to ensure a slow drug release. In addition, the differences on the release profiles between PEG-40 stearate-based nanoparticles, PEG-40 stearate acrylate based and polymerized ones, were analyzed under conditions, simulating the typical environment of Candida albicans infection. Then, the antifungal activity of nanoparticles was also evaluated in terms of minimal inhibitory concentration. Moreover, the nanoparticles were submitted to in vitro studies for evaluating the drug permeability at the site of action. Results indicated that the obtained particles are potentially useful for the treatment of vaginal infections sustained by Candida albicans.

Recent Advances in the Synthesis and Biomedical Applications of Nanocomposite Hydrogels.

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.

Photostability and ex-vivo permeation studies on diclofenac in topical niosomal formulations.

Photostability studies were performed on topical formulations containing diclofenac (DC). Niosomal gels were designed as photostabilization systems and ascorbic acid was also added to the new topical formulations because of its antioxidant property. Photodegradation tests were applied on commercial formulations containing DC and novel prepared gels, according to the ICH rules. The experiments were monitored by spectrophotometry and the data processed by multivariate curve resolution analysis to estimate the spectra and concentration profiles of evolved components. Characterization of niosomes was evaluated by size and distribution measurement, morphological analysis and encapsulation efficiency. Permeation experiments were performed across rabbit ear skin up to 24 h. Photodegradation rate of DC was found very fast in commercial formulation, with a residual content of 90% after only 4.38 min under a radiant exposure of 450 W/m(2). Photostability resulted increased significantly when the drug was entrapped in niosomal systems. The best results were obtained by reaching a 10% degradation after 50.00 min of light exposure after incorporation of DC in niosomes in presence of 5% ascorbic acid. Moreover, niosomal gel also influenced the permeation capability of DC by enhancing the transdermal delivery of the drug. The cumulative dose permeated of DC from niosomal gel was about three times that obtained with the commercial gel.

Novel pH sensitive ferrogels as new approach in cancer treatment: Effect of the magnetic field on swelling and drug delivery.

Ferrogels (or magnetic hydrogels) are cross-linked polymer networks containing magnetic nanoparticles: they are mechanically soft and highly elastic and at the same time they exhibit a strong magnetic response. Our work focuses on an combinatorial strategy to improve the efficacy of 5-Fluorouracil (5-FU) assisted chemotherapy, by developing novel multifunctional pH-sensitive ferrogels. We designed gels based on N,N'-dimethylacrylamide monomers polymerized in presence of methacrylic acid or 2-aminoethyl methacrylate hydrochloride, containing ferro-nanoparticles. The influence of polymeric matrix composition and exposition to magnetic field (MF) on swelling behavior and drugs release were investigated at pH 7.4 and 5. In particular, the magnetic field was obtained by using permanent magnetic bar (0.25 T) or electromagnet (0.5 and 1.2 T), with the aim to analyze quantitatively the magnetic effects. A strong influence of the magnetic field on ferrogels properties have been observed. Swelling analysis indicated a dependence on both pH and network composition, reaching a maximum at pH 7.4, for formulations containing methacrylic acid, while the application of MF appeared to decrease the swelling percentages. Release profiles of 5-FU showed effective modulation in release by application of MF: drug release is always higher in the presence of a magnetic field and generally increases with its intensity. The combining effect of pH sensitive properties and application of MF improved the performance of the systems. Results showed that our ferrogels may be technologically applicable as devices for delivery of 5-FU in a controllable manner.

Coated biodegradable casein nanospheres: a valuable tool for oral drug delivery.

Biodegradable casein nanospheres for the sustained release of bioactive molecules in the gastro-intestinal tract were prepared by precipitation polymerization using sodium methacrylate (NaMA) and N,N'-methylene bis-acrylamide (MEBA) as pH-responsive monomer and cross-linker. Three materials with different casein amount were obtained and characterized by scanning electron microscopy, dimensional analysis, water uptake, cytotoxicity and enzymatic degradation experiments. Nanospheres biodegradability was tuned by coating with polyacrylic acid. Coated and uncoated materials were investigated as delivery vehicles for diclofenac sodium salt. For un-coated samples, the release raise 100% in 30 h, while for coated specimens these values were lower than 70%, due to the diffusional constraints of polymer layer.

Determination of biogenic amine profiles in conventional and organic cocoa-based products.

Cocoa contains many compounds such as biogenic amines (BAs), known to influence consumer health. Spermidine, spermidine, putrescine, histamine, tyramine, ß-phenylethylamine, cadaverine and serotonine have been found in several cocoa-based products using HPLC with UV detection after derivatisation with dansyl-chloride. Once optimised in terms of linearity, percentage recovery, LOD, LOQ and repeatability, this method was applied to real samples. Total concentrations of BAs ranged from 5.7 to 79.0 µg g(-)(1) with wide variations depending on the type of sample. BAs present in all samples were in decreasing order: histamine (1.9-38.1 µg g(-)(1)) and tyramine (1.7-31.7 µg g(-)(1)), while putrescine (0.9-32.7 µg g(-)(1)), spermidine (1.0-9.7 µg g(-)(1)) and spermidine (0.6-9.3 µg g(-)(1)) were present in most of the samples. Cadaverine, serotonine and ß-phenylethylamine were present in a few samples at much lower concentrations. Organic samples always contained much lower levels of BAs than their conventional counterparts and, generally speaking, the highest amounts of BAs were found in the most processed products.

Brewing effect on levels of biogenic amines in different coffee samples as determined by LC-UV.

Eight biogenic amines (spermine, spermidine, putrescine, histamine, tyramine, phenylethylamine, cadaverine and serotonin) were determined by LC-UV after derivatization with dansyl-chloride in both ground coffee and coffee beverages obtained by different methods. In ground coffee, the most relevant amine was PUT, followed by SPD, HIS, TYR, CAD, SPM, PHE, and SER, with the total BAs content decreasing as the roasting degree increased. In coffee brews, the order was PUT, SPM, TYR, CAD, SPD, PHE, HIS, and SER, but at a very low level in comparison with the amount of BAs determined in roasted ground coffee. Beverages prepared by espresso, capsule, and pod machines had the lowest BAs contents, as a result of the thermal and physical stress imposed on ground coffee by these methods, while mocha contained the highest BAs amounts owing to lower pressure and longer brewing time.

Tunable thermo-responsive hydrogels: synthesis, structural analysis and drug release studies.

Thermo-responsive hydrogel films, synthesized by UV-initiated radical polymerization, are proposed as delivery devices for non-steroidal anti-inflammatory drugs (Diclofenac sodium and Naproxen). N-isopropylacrylamide and N,N'-ethylenebisacrylamide were chosen as thermo-sensitive monomer and crosslinker, respectively. Infrared spectroscopy was used to assess the incorporation of monomers into the network, and the network density of hydrogel films was found to strictly depend on both feed composition and film thickness. Calorimetric analyses showed negative thermo-responsive behaviour with shrinking/swelling transition values in the range 32.8-36.1°C. Equilibrium swelling studies around the LCST allowed the correlation between the structural changes and the temperature variations. The mesh size, indeed, rapidly changed from a collapsed to a swollen state, with beneficial effects in applications such as size-selective permeation or controlled drug delivery, while the crosslinking degree, the film thickness, and the loading method deeply influenced the drug release profiles at 25 and 40°C. The analysis of both 3D-network structure, release kinetics and diffusional constraints at different temperatures was evaluated by mathematical modelling.