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Durum wheat is widely cultivated in the Mediterranean, where it is the basis for the production of high added-value food derivatives such as pasta. In the next few years, the detrimental effects of global climate change will represent a serious challenge to crop yields. For durum wheat, the threat of climate change is worsened by the fact that cultivation relies on a few genetically uniform, elite varieties, better suited to intensive cultivation than “traditional” ones but less resistant to environmental stress. Hence, the renewed interest in “ancient” traditional varieties are expected to be more tolerant to environmental stress as a source of genetic resources to be exploited for the selection of useful agronomic traits such as drought tolerance. The aim of this study was to perform a comparative analysis of the effect and response of roots from the seedlings of two durum wheat cultivars: Svevo, a widely cultivated elite variety, and Saragolla, a traditional variety appreciated for its organoleptic characteristics, to Polyethylene glycol-simulated drought stress. The effect of water stress on root growth was analyzed and related to biochemical data such as hydrogen peroxide production, electrolyte leakage, membrane lipid peroxidation, proline synthesis, as well as to molecular data such as qRT-PCR analysis of drought responsive genes and proteomic analysis of changes in the protein repertoire of roots from the two cultivars.

This paper represents the first result of an active collaboration between the University of Sannio and the San Pio Hospital (Benevento, Italy), started in the 2018, that aims to a detailed mineralogical investigation of urinary stones of patients from Campania region. Herein, selected human bladder stones have been deeply characterized for clinical purposes and environmental biomonitoring, focusing on the importance to evaluate the concentration and distribution of undesired trace elements by means of microscopic techniques in the place of conventional wet chemical analyses. A rare bladder stones with a sea-urchin appearance, known as jackstone calculus, were also investigated (along with bladder stones made of uric acid and brushite) by means a comprehensive analytical approach, including Synchrotron X-ray Diffraction and Simultaneous Thermal Analyses. Main clinical assumptions were inferred according to the morpho-constitutional classification of bladder stones and information about patient’s medical history and lifestyle. In most of the analyzed uroliths, undesired trace elements such as copper, cadmium, lead, chromium, mercury and arsenic have been detected and generally attributable to environmental pollution or contaminated food. Simultaneous occurrence of selenium and mercury should denote a methylmercury detoxification process, probably leading to the formation of a very rare HgSe compound known as tiemannite.

Here, an unprecedented biorefinery approach has been designed to recover high-added value bioproducts starting from the culture of Porphyridium cruentum. This unicellular marine red alga can secrete and accumulate high-value compounds that can find applications in a wide variety of industrial fields. 300 ± 67 mg/L of exopolysaccharides were obtained from cell culture medium; phycoerythrin was efficiently extracted (40% of total extract) and isolated by a single chromatography, with a purity grade that allowed the crystal structure determination at 1.85 Å; a 2-fold increase in β-carotene yield was obtained from the residual biomass; the final residual biomass was found to be enriched in saturated fatty acids. Thus, for the first time, a complete exploitation of P. cruentum culture was set-up.

The present investigation exposes the main results raised from an active collaboration started in 2018 with the San Pio Hospital (Benevento, Southern Italy), aiming at a detailed mineralogical investigation of urinary stones of patients from the Campania region. Forty-nine uroliths (both bladder and kidney stones) have been surgically collected from patients admitted between 2018 and 2020 at the Department of Urology of the San Pio Hospital and characterized for clinical purposes and environmental biomonitoring from a mineralogical point of view. Possible causes and environmental implications were inferred according to the morpho-constitutional classification of the uroliths carried out by means of a conventional analytical approach. The mineralogical frequency distribution of uroliths from the Campanian region can be discussed as a function of dietary, socio-demographic, and environmental risk factors. Whewellite [CaC2O4·H2O] and weddellite [CaC2O4·(2+x)H2O], along with anhydrous calcium oxalate, represent the main mineralogical phases forming the biominerals examined here. Worth to note is that the percentage of oxalates in the Campanian region (ca. 51%) is quite comparable to those of other Mediterranean areas. Frequent uricite [C5H4N4O3] (ca. 33%), mainly observed in bladder stones of older male patients, could be related to an incorrect lifestyle and dietary habits. Occurrence of lower percentages of phosphate (i.e., brushite [CaHPO4·2(H2O)] and carbonated apatite [Ca10(PO4CO3)6(OH)8]) and mixed stones (such as, for example, a mixture of ammonium urate [NH4C5H3N4O3] and calcium oxalates) indicates specific etiopathogenetic mechanisms, suggesting proper therapeutical approaches.

In the present study, we aimed at assessing the influence of breed and feeding system on the bovine milk profile of betaines and carnitines and milk capacity in counteracting the inflammatory endothelial cell (EC) damage induced by interleukin (IL)-6. In the first experimental design, two breeds were chosen (Holstein vs. Modicana) to investigate the biomolecule content and antioxidant capacity in milk and dairy products. In the second experimental design, two feeding systems (pasture vs. total mixed ratio) were tested only in Holstein to evaluate the possible effect on the functional profile of milk and dairy products. Finally, the bulk milk from the two experimental designs was used to evaluate the efficacy of preventing IL-6-induced endothelial inflammatory damage. Results showed that Modicana milk and whey had higher biomolecule content and antioxidant activity compared to Holstein milk (p < 0.01). Milk from Holstein fed TMR showed higher concentration of γ-butyrobetaine, δ-valerobetaine (p < 0.01), and l-carnitine (p < 0.05). Similarly, whey from Holstein fed TMR also showed higher content of δ-valerobetaine, glycine betaine, l-carnitine, and acetyl-l-carnitine (p < 0.01) compared to the Holstein fed pasture. Conversely, the antioxidant activity of milk and dairy products was not affected by the feeding system. In ECs, all milk samples reduced the IL-6-induced cytokine release, as well as the accumulation of reactive oxygen species (ROS) and the induction of cell death, with the most robust effect elicited by Modicana milk (p < 0.01). Overall, Modicana milk showed a higher content of biomolecules and antioxidant activity compared to Holstein, suggesting that the breed, more than the feeding system, can positively affect the health-promoting profile of dairy cattle milk.

Recently, glycerol has been exploited in a number of industrial applications, thanks to its high availability, its low cost and, overall, its peculiar properties which fit well with the green chemistry principles. In this work, the ability of glycerol to solubilize high molecular weight polymers and to allow the formation of glycerol-based semi-interpenetrating polymer networks, called “gly-semi-IPNs”, has been investigated. Compared to water, glycerol deeply affects the structural properties of the biopolymers, especially with reference to their chain flexibility. Among the polysaccharides, dextran methacrylate (DexMA) and gellan gum (Ge) were selected. Glycerol solutions of both polysaccharides and their mixtures, as well as a DexMA network (obtained by cross-linking in glycerol and in the presence of a photoinitiator), were rheologically characterized to assess the role of the solvent on the chain conformation and on the mechanical properties of the networks. Interestingly, glycerol was found to deeply influence the mechanical, morphological and optical properties of the formed hydrogels, as well as to improve the cross-linking kinetic of DexMA. Furthermore, glycerol leads to more homogeneous mixtures of the two polysaccharides than those observed in aqueous buffers. As such, novel gly-semi-IPNs, with enhanced formulation and mechanical properties, were prepared and characterized.

A major function of the intrahepatic biliary epithelium is bicarbonate excretion in bile. Recent reports indicate that budesonide, a corticosteroid with high receptor affinity and hepatic first pass clearance, increases the efficacy of ursodeoxycholic acid, a choleretic agent, in primary biliary cholangitis patients. We have previously reported that bile ducts isolated from rats treated with dexamethasone or budesonide showed an enhanced activity of the Na+/H+ exchanger isoform 1 (NHE1) and Cl−/HCO3− exchanger protein 2 (AE2) . Increasing the delivery of steroids to the liver may result in three beneficial effects: increase in the choleresis, treatment of the autoimmune or inflammatory liver injury and reduction of steroids’ systemic harmful effects. In this study, the steroid dexamethasone was loaded into nanohydrogels (or nanogels, NHs), in order to investigate corticosteroid-induced increased activities of transport processes driving bicarbonate excretion in the biliary epithelium (NHE-1 isoform) and to evaluate the effects of dexamethasone-loaded NHs (NHs/dex) on liver injury induced by experimental cholestatis. Our results showed that NHs and NHs/dex do not reduce cell viability in vitro in human cholangiocyte cell lines. Primary and immortalized human cholangiocytes treated with NHs/dex show an increase in the functional marker expression of NHE1 cholangiocytes compared to control groups. A mouse model of cholangiopathy treated with NHs/dex shows a reduction in markers of hepatocellular injury compared to control groups (NHs, dex, or sham group). In conclusion, we believe that the NHs/dex formulation is a suitable candidate to be investigated in preclinical models of cholangiopathies. Graphical abstract

The anatomy and physiology of the eye strongly limit the bioavailability of locally administered drugs. The entrapment of therapeutics into nanocarriers represents an effective strategy for the topical treatment of several ocular disorders, as they may protect the embedded molecules, enabling drug residence on the ocular surface and/or its penetration into different ocular compartments. The present work shows the activity of hyaluronan-cholesterol nanogels (NHs) as ocular permeation enhancers. Thanks to their bioadhesive properties, NHs firmly interact with the superficial corneal epithelium, without penetrating the stroma, thus modifying the transcorneal penetration of loaded therapeutics. Ex vivo transcorneal permeation experiments show that the permeation of hydrophilic drugs (i.e., tobramycin and diclofenac sodium salt), loaded in NHs, is significantly enhanced when compared to the free drug solutions. On the other side, the permeation of hydrophobic drugs (i.e., dexamethasone and piroxicam) is strongly dependent on the water solubility of the entrapped molecules. The obtained results suggest that NHs formulations can improve the ocular bioavailability of the instilled drugs by increasing their preocular retention time (hydrophobic drugs) or facilitating their permeation (hydrophilic drugs), thus opening the route for the application of HA-based NHs in the treatment of both anterior and posterior eye segment diseases.

Hyaluronic acid (HA) is one of the most used biopolymers in the development of drug delivery systems, due to its biocompatibility, biodegradability, non-immunogenicity and intrinsic-targeting properties. HA specifically binds to CD44, this property combined to the EPR effect could provide an option for reinforced active tumor targeting by nanocarriers, improving drug uptake by the cancer cells via the HA-CD44 receptor-mediated endocytosis pathway. Moreover, HA can be easily chemically modified to tailor its physico-chemical properties in view of specific applications. The derivatization with cholesterol confers to HA an amphiphilic character, and then the ability of anchoring to niosomes. HA-Chol was then used to coat Span® or Tween® niosomes providing them with an intrinsic targeting shell. The nanocarrier physico-chemical properties were analyzed in terms of hydrodynamic diameter, ζ-potential, and bilayer structural features to evaluate the difference between naked and HA-coated niosomes. Niosomes stability was evaluated over time and in bovine serum. Moreover, interaction properties of HA-coated nanovesicles with model membranes, namely liposomes, were studied, to obtain insights on their interaction behavior with biological membranes in future experiments. The obtained coated systems showed good chemical physical features and represent a good opportunity to carry out active targeting strategies.

The development of an electrochemical cell based on poly(vinyl alcohol) (PVA) hydrogel as polymer electrolyte for electrochemical impedance spectroscopy analysis (EIS) is discussed. PVA hydrogel is prepared with different cycles of freeze/thawing (F/T) employing distillated and mineral water as solutions. The PVA-disks obtained are compared for their conductivities in order to employ it in an appropriate cell for diagnostic purposes, reducing the invasiveness of the analysis on the sample. The test of the self-consistent disk of PVA is carried out on a modern sample of copper and on an archaeological bronze coin, obtaining an alternative of the classical electrochemical cell for EIS measurements on ancient metals.

This paper represents the first result of an active collaboration between the University of Sannio and the San Pio Hospital (Benevento, Italy), started in the 2018, that aims to a detailed mineralogical investigation of urinary stones of patients from Campania region. Herein, selected human bladder stones have been deeply characterized for clinical purposes and environmental biomonitoring, focusing on the importance to evaluate the concentration and distribution of undesired trace elements by means of microscopic techniques in the place of conventional wet chemical analyses. A rare bladder stone with a sea-urchin appearance, known as jackstone calculus, were also investigated (along with bladder stones made of uric acid and brushite) by means a comprehensive analytical approach, including Synchrotron X-ray Diffraction and Simultaneous Thermal Analyses. Main clinical assumptions were inferred according to the morpho-constitutional classification of bladder stones and information about patient's medical history and lifestyle. In most of the analyzed uroliths, undesired trace elements such as copper, cadmium, lead, chromium, mercury and arsenic have been detected and generally attributable to environmental pollution or contaminated food. Simultaneous occurrence of selenium and mercury should denote a methylmercury detoxification process, probably leading to the formation of a very rare HgSe compound known as tiemannite.

In the last years, great importance has been given to the beneficial effects of polyphenols [1]. Agricultural by-products are a rich source of polyphenols and have a potential suitable for development into dietary supplements and various food additives [2]. The objective of the present research was to investigate gut morphology, inflammation and immune response of adult pigs (Casertana strain) fed with polyphenols extracted from olive mill wastewater added to the standard diet, by in vivo and in vitro analysis. The ‘Casertana’ pig is an ancient autochthon genetic type and represents an experimental model suitable for semi-wild controlled breeding technique. During the finishing period, pigs were randomly assigned in two groups: control group fed with a standard diet and treated group fed with standard diet supplemented with polyphenols extracted from olive mill wastewater (OMWW) using capsules (0.03 g/kg of feed per pig per day) [3]. The trial lasted for 120days. After slaughter, alveolar macrophages were extracted from pig lungs [4] and the superoxide anion assay was performed to test the anti-oxidant effects of polyphenols extracted from OMWW. Gastrointestinal tracts (stomach, duodenum, jejunum, ileum, caecum and colon) were collected from all animals, embedded in paraffin wax, serially cut in transversal sections and stained with hematoxylin– eosin for histomorphometric analysis. No significant differences in the length of the jejunum-ileum villi and the depth of the colon crypts were detected between control and polyphenols fed pigs. COX-2 immunoreactivity in the gastrointestinal tract was more intense in the control group. The low level of expression of COX-2 in immunoreactive cells in the intestine of treated pigs could suggests a protective role of polyphenols, modulating and reducing the inflammatory response [5]. Superoxide anion production in alveolar macrophages was lower in pigs fed polyphenols (p

Wound healing, especially diabetic ones, is a relevant clinical problem, so it is not surprising that surgical procedures are often needed. To overcome invasive procedures, several strategies with drugs or natural compound are used. Recently, in an experimental study, we described an increase in keratinocyte proliferation after their exposition to quercetin plus oleic acid. In the present clinical study, we evaluated both the clinical efficacy and the safety of nano-hydrogel embedded with quercetin and oleic acid in the treatment of lower limb skin wound in patients with diabetes mellitus (DM). Fifty-six DM patients (28 men and 28 women, mean age 61.7 ± 9.2 years) unsuccessfully treated with mechanical compression were enrolled and randomised to receive an add on treatment with hyaluronic acid (0.2%) or nano-hydrogel embedded with quercetin and oleic acid. The treatment with nano-hydrogel embedded with quercetin and oleic acid significantly (P < .01) reduced the wound healing time, in comparison to hyaluronic acid (0.2%) without developing of adverse drug reactions, suggesting that this formulation could be used in the management of wound healing even if other clinical trials must be performed in order to validate this observation.

[EN] In the present work, the preparation, characterization and therapeutic potential of baicalin-loaded nanohydrogels are reported. The nanohydrogels were prepared by sonicating (S nanohydrogel) or autoclaving (A nanohydrogel) a dispersion of cholesterol-derivatized gellan in phosphate buffer. The nanohydrogel obtained by autoclave treatment showed the most promising results: smaller particles ( similar to 362 nm vs. similar to 530 nm), higher homogeneity (polydispersity index = similar to 0.24 vs. similar to 0.47), and lower viscosity than those obtained by sonication. In vitro studies demonstrated the ability of the nanohydrogels to favour the deposition of baicalin in the epidermis. A high biocompatibility was found for baicalin-loaded nanohydrogels, along with a great ability to counteract the toxic effect induced by hydrogen peroxide in cells, as the nanohydrogels re-established the normal conditions (similar to 100% viability). Further, the potential of baicalin-loaded nanohydrogels in skin wound healing was demonstrated in vivo in mice by complete skin restoration and inhibition of specific inflammatory markers (i.e., myeloperoxidase, tumor necrosis factor-alpha, and oedema., Financial support from University "Sapienza" - Progetti di Ricerca: grant RP116154C2EF9AC8 and grant RM11715C1743EE89 are acknowledged.

Highly hydrophilic and biocompatible nanocarriers based on polysaccharide hydrogels (nanohydrogels, NHs) were shown to be promising systems for drug delivery applications. Following the idea of these emerging drug carriers, the aim of the present work was to develop self-assembled hydrogel nanoparticles based on amphiphilic derivatives of hyaluronic acid (HA) and riboflavin (Rfv), synthesized by "click" Copper(I)-catalyzed Azide-Alkyne Cycloaddition (CuAAC) reaction. The obtained amphiphilic product (HA-c-Rfv) was able to form nanohydrogels in aqueous environments, in particular by applying an innovative autoclave-based method. HA of different molecular weights (Mw) and degrees of substitution (DS) were prepared and the effect of these parameters on the NHs formation was assessed. The derivative HA220-c-Rfv 40/40 was chosen as the most interesting system, capable to form NHs in the range of 150-200nm and with a negative ζ-potential. NHs were very stable in water solutions and, by adding dextrose as cryoprotectant, it was also possible to freeze-dry the NHs formulation. The developed system is proposed for the delivery of hydrophobic drugs; for this purpose, dexamethasone, piroxicam and paclitaxel were used as model drugs; these molecules were loaded into NHs with high efficiency by film-hydration technique. Furthermore, a HA-c-Rfv derivative bearing an excess of propargylic portions was capable to react with other N3-derivatized molecules, opening the route to a wide spectrum of functionalization opportunities: in this direction, PEG-N3 has been tested as a model molecule for the preparation of PEGylated NHs.

Aim: To elucidate whether different cytokinetic features (i.e., presence or absence of mitotic activity) may influence cell uptake and distribution of nanocarriers, in vitro tests on liposomes, mesoporous silica nanoparticles, poly(lactide-co-glycolide) nanoparticles and nanohydrogels were carried out on C2C12 murine muscle cells either able to proliferate as myoblasts (cycling cells) or terminally differentiate into myotubes (noncycling cells). Materials & methods: Cell uptake and intracellular fate of liposomes, mesoporous silica nanoparticles, poly(lactide-co-glycolide) nanoparticles and nanohydrogels were investigated by confocal fluorescence microscopy and transmission electron microscopy. Results: Nanocarrier internalization and distribution were similar in myoblasts and myotubes; however, myotubes demonstrated a lower uptake capability. Conclusion: All nanocarriers proved to be suitably biocompatible for both myoblasts and myotubes. The lower uptake capability of myotubes is probably due to different plasma membrane composition related to the differentiation process.

Water structure and dynamics are investigated by 1H NMR in a polysaccharide interpenetrating polymer network (IPN) based on calcium alginate and methacrylated hyaluronic acid. The effects of two solvents, water and a saline NaCl solution, on the transport properties of water and on the polymer structure are analyzed. Anomalous diffusion behavior of water in the different samples is investigated and correlated to the polymer structure. Up to three water fractions are detected in the IPN samples having different hydrogen bond network structure and diffusion properties. This work highlights how the aggregation of hydrophobic domains in amphiphilic hydrogels influences the transport properties of solvent water. In addition, the results emphasize the effect of charged ions, used to improve hydrogel biocompatibility, on the polymer network structure and of polymer interpenetration mechanisms.

This overview follows the evolution of the studies carried out, mainly during last years, on polysaccharide hydrogels, with particular attention on the researches carried out in our department, often in collaboration with other groups in our country and abroad. The review points out the importance of this type of networks for the optimization of drug delivery and targeting in the various forms of macro, micro and nano systems. It is also shown that these materials are suitable for the culture of different types of cells. Release mechanisms are reported and explained by different physico-chemical approaches and by means of molecular dynamics simulations and the anomalous swelling behavior of a scleroglucan/borax hydrogel is thoroughly discussed. The role of polymer combinations forming interpenetrated structures is explained in terms of specific properties which significantly differ from those of the constituent polymers, thus allowing appropriate tailoring of the delivery rates. Finally the wide possibilities of applications of nanogel structures which allow combination therapies for cancer treatment and can be suitable for intracellular targeting are reported. The studies on polysaccharide hydrogels are still in progress and it is underlined that future researches, more focused on the passage from lab to market, should be further stimulated.

[EN] Nanohydrogels based on natural polymers, such as polysaccharides, are gaining interest as vehicles for therapeutic agents, as they can modify the pharmacokinetics and pharmacodynamics of the carried drugs. In this work, hyaluronan-riboflavin nanohydrogels were tested in vivo in healthy rats highlighting their lack of toxicity, even at high doses, and their different biodistribution with respect to that of native hyaluronan. They were also exploited as carriers of a hydrophobic model drug, the anti-inflammatory piroxicam, that was physically embedded within the nanohydrogels by an autoclave treatment. The nanoformulation was tested by intravenous administration showing an improvement of the pharmacokinetic parameters of the molecule. The obtained results indicate that hyaluronan-based self-assembled nanohydrogels are suitable systems for low-soluble drug administration, by increasing the dose as well as the circulation time of poorly available therapeutic agents., Financial support from University Sapienza Progetti di Ricerca: grant RP116154C2EF9AC8 and grant RM11715C1743EE89 are acknowledged. Isabel Gonzalez-Alvarez, Marta Gonzalez-Alvarez and Marival Bermejo acknowledge partial financial support to project SAF2016-78756 from MINECO (Spanish Ministry of economy, industry and competitivity). Mayte Martinez-Martínez received a grant from the Ministry of Education and Science of Spain (FPU13-01105).

Hyaluronan (HA) is among the most important bioactive polymers in mammals, playing a key role in a number of biological functions. In the last decades, it has been increasingly studied as a biomaterial for drug delivery systems, thanks to its physico-chemical features and ability to target and enter certain cells. The most important receptor of HA is ‘Cluster of Differentiation 44’ (CD44), a cell surface glycoprotein over-expressed by a number of cancers and heavily involved in HA endocytosis. Moreover, CD44 is highly expressed by keratinocytes, activated macrophages and fibroblasts, all of which can act as ‘reservoirs’ for intracellular pathogens. Interestingly, both CD44 and HA appear to play a key role for the invasion and persistence of such microorganisms within the cells. As such, HA is increasingly recognised as a potential target for nano-carriers development, to pursuit and target intracellular pathogens, acting as a ‘Trojan Horse’. This review describes the biological relationship between HA, CD44 and the entry and survival of a number of pathogens within the cells and the subsequent development of HA-based nano-carriers for enhancing the intracellular activity of antimicrobials.

The feasibility to use gellan nanohydrogels (Ge-NHs) as delivery system for the cutaneous administration of piroxicam (PRX) was investigated using gellan conjugated with cholesterol or riboflavin. The in vitro skin penetration studies through human epidermis were performed using a saturated aqueous drug solution, a 50% w/v Transcutol aqueous solution, and a commercially available PRX plaster as controls. Confocal microscopy, ATR-FTIR spectroscopy, circular dichroism, and a dynamometer assisted extrusion assay were performed to clarify the permeation mechanism of Ge-NHs. The skin permeation studies evidenced that Ge-NHs enhance the PRX retention in the epidermis and, at the same time, slow down the permeation process with respect to the controls. NHs can penetrate the stratum corneum, and then gradually disassemble thus diffusing in the viable epidermis reaching the spinosum layer. In conclusion, NHs represent a novel strategy to target poorly permeable compounds in the epidermis, thus improving the management of cutaneous pathologies.

Staphylococcus aureus is one of the most significant human pathogens that is frequently isolated in a wide range of superficial and systemic infections. The ability of S. aureus to invade and survive within host cells such as keratinocytes and host immune cells has been increasingly recognized as a potential factor in persistent infections and treatment failures. The incorporation of antibiotics into hyaluronan-cholesterol nanohydrogels represents a novel paradigm in the delivery of therapeutic agents against intracellular bacteria. The work presented herein shows that NHs quickly enter human keratinocytes and accumulate into lysosomes. When used for targeting intracellular S. aureus the antimicrobial activity of loaded levofloxacin is enhanced, possibly changing the antibiotic intracellular fate from cytosol to lysosome. Indeed, gentamicin, an antibiotic that predominantly accumulates in lysosomes, shows significant and equal antibacterial activity when entrapped into NHs. These results strongly suggest that lysosomal formulations may display preferential activity toward intracellular S. aureus, opening new avenues for the use of HA-based NHs for treatment of such skin infections.

The effects that an increase of environmental pH has on the triple helix of scleroglucan (Sclg) and on the Sclg/borax hydrogel are reported. Rheological experiments show that the hydrogel is less sensitive to pH increase than Sclg alone, while at pH = 14 a dramatic viscosity decrease takes place for both systems. This effect is evidenced also by the reduced water uptake and anisotropic elongation detected, at pH = 14, by the swelling behaviour of tablets prepared with the Sclg/borax system. On the opposite, a different behaviour was observed with guar gum and locust bean gum tablets, tested as reference polysaccharides. The effect of pH on the structure of Sclg and Sclg/borax was investigated also by means of spectroscopic approaches based on the interaction between Congo red (CR) and the Sclg triple helix. Obtained results indicated that the CR absorbance maximum is shifted as a function of pH and by the presence of borax. Principal component analysis allowed very precise identification of the pH value at which the Sclg helix collapses. Molecular dynamics simulations of the Sclg/borax–CR complex indicated that, at physiological pH, only a few ordered configurations are populated, according to the induced circular dichroism (CD) spectrum evidence.

Although in recent years several methods have been studied and developed to obtain different types of nanosized drug delivery systems, the set up of suitable procedures and materials remains highly expensive, their preparation is time consuming and often not feasible for a scale-up process. Furthermore, the sterilisation and storage of nanocarrier formulations represents a complicated but mandatory step for their effective use. In our previous work we assessed the use of an autoclaving process to achieve, in one simple step, sterile self-assembled hyaluronan-cholesterol (HA-CH) and hyaluronan-riboflavin (HA-Rfv) nanohydrogels (NHs). In the present work, the effect of the high temperature on HA-CH has been studied in detail. HA-CH suspensions were characterised in terms of size and polydispersity by Dynamic Light Scattering at different temperatures and conditions; the HA-CH chemical structure and its molecular weight were assessed via FT-IR and GPC analysis after the sterilising cycle in an autoclave at 121. °C for 20. min. The obtained NHs were then observed with TEM and AFM microscopy, in both dry and liquid conditions. The Young's modulus of the NHs was determined, evidencing the soft nature of these nanosystems; the critical aggregation concentration (c.a.c) of the nanosuspension was also assessed. Thereafter, alginate lyase (AL) was conjugated to NHs, with the aim of developing a useful system for therapies against bacterial infections producing alginate biofilms. The conjugation efficiency and the enzymatic activity of AL were determined after immobilisation. The AL-NHs system showed the ability to depolymerise alginate, offering an opportunity to be a useful nanosystem for the treatment of biofilm-associated infections.

During the last decades, it has become evident that inflammation plays a critical role in tumorigenesis: tumor microenvironment is largely orchestrated by inflammatory cells. In the present work, a novel gellan gum nanohydrogel system (NH) able to carry and deliver simultaneously anti-cancer and anti-inflammatory drugs was developed. Prednisolone was chemically linked to the carboxylic groups of gellan gum to serve as a hydrophobic moiety promoting nanohydrogel formation, whereas paclitaxel was then physically entrapped in it. NH improved drug performances, acting as paclitaxel and prednisolone solubility enhancer and favoring the drug uptake in the cells. Moreover, NH allowed an increased cytotoxic effect in vitro on several types of cancer cells due to the synergistic effect of the combination of anti-inflammatory and anti-cancer drugs. Thus, NH can be useful in a combination therapy that attacks both, malignant cells and tumor inflammatory components.

Natural antioxidants, such as astaxanthin (AX), resveratrol (RV) and curcumin (CU), are bioactive molecules that show a number of therapeutic effects. However, their applications are remarkably limited by their poor water solubility, physico-chemical instability and low bioavailability. In the present work, it is shown that self-assembled hyaluronan (HA)-based nanohydrogels (NHs) are taken up by endothelial cells (Human Umbilical Vein Endothelial Cells, HUVECs), preferentially accumulating in the perinuclear area of oxidatively stressed HUVECs, as evidenced by flow cytometry and confocal microscopy analyses. Furthermore, NHs are able to physically entrap and to significantly enhance the apparent water solubility of AX, RV and CU in aqueous media. AX/NHs, RV/NHs and CU/NHs systems showed good hydrodynamic diameters (287, 214 and 267 nm, respectively), suitable &zeta, potential values (&minus, 45, &minus, 43 and &minus, 37 mV, respectively) and the capability to neutralise reactive oxygen species (ROS) in tube. AX/NHs system was also able to neutralise ROS in vitro and did not show any toxicity against HUVECs. This research suggests that HA-based NHs can represent a kind of nano-carrier suitable for the intracellular delivery of antioxidant agents, for the treatment of oxidative stress in endothelial cells.

An alternative anticancer therapy based on the use of bovine serum amine oxidase (BSAO), an enzyme that converts polyamines over-expressed in malignant cells, into hydrogen peroxide and aldehyde(s), thus inducing high cytotoxicity in cancer cells, was recently proposed. With the aim of improving the system efficacy by exploiting a nanotechnology approach, BSAO is covalently immobilized onto injectable nanohydrogels (NHs) based on cholesterol-graft-hyaluronic acid (HA-CH), a biocompatible conjugate that spontaneously leads to self-assembled structures in aqueous solutions. In this study, the physicochemical properties of the HA-CH-based NHs and the NHs cytocompatibility are reported. The properties of the NHs-BSAO system are also studied in terms of protein residual activity, both in vitro and on a model melanoma cell line.

Guar Gum is a natural polysaccharide that, due to its physicochemical properties, is extensively investigated for biomedical applications as a matrix for modified drug delivery, but it is also used in the food industry as well as in cosmetics. A commercial sample of Guar Gum was sonicated for different periods of time, and the reduction in the average molecular weight was monitored by means of viscometric measurements. At the same time, the rheological behaviour was also followed, in terms of viscoelasticity range, flow curves, and mechanical spectra. Sonicated samples were used for the preparation of gels in the presence of borate ions. The effect of borax on the new samples was investigated by recording mechanical spectra, flow curves, and visible absorption spectra of complexes with Congo Red. The anisotropic elongation, observed in previous studies with tablets of Guar Gum and borax, was remarkably reduced when the sonicated samples were used for the preparation of the gels.

Scleroglucan is a fungal polysaccharide that, when dispersed in water, assumes a very stable triple helix structure. It has numerous industrial applications in different fields, such as food industry, cosmetics, and pharmaceutics. In the presence of borate ions, this polymer forms weak gels that, after freeze-drying and compaction, show an anisotropic swelling behavior, related to the borate/polymer ratio. By monitoring the evolution of the elastic and viscous moduli it was possible to follow the gel formation kinetics. The rheological properties of the network were studied as a function of crosslinking agent concentration and the corresponding flow curves and mechanical spectra were recorded. The kinetics of the crosslinking reaction was monitored by following the time evolution of the storage and loss moduli, after the addition of borate ions to the Scleroglucan system. Creep-recovery experiments allowed acquiring recoverable strain values and those of the critical stress above which a very high compliance of the sample is reached. Obtained results are to be related to the specific type of bonds between the polysaccharide chains and the crosslinking agent. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42860.

International audience; The preparation of a novel polysaccharidic inter-penetrating polymer network based on calcium alginate (AlgCa) and methacrylated hyaluronic acid is described. The effect of two different solvents, distilled water and 0.9 % (w/v) NaCl, on the matrix formation and on its physico-chemical properties was studied by means of rheological and mechanical measurements. Furthermore, the structural characterization of the hydrogels prepared in the different ionic strength conditions was carried out by small-angle X-ray scattering in order to obtain deeper information useful for the preparation of drug delivery systems. Finally, to evaluate the potential use of the novel matrix as a drug delivery system and, in particular, its suitability for modulated delivery of a bioactive protein, release experiments of horseradish peroxidase, as a model protein, were also carried out.