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The encapsulation and organization of Bifidobacterium animalis subsp. lactis (BIFIDO) probiotic cells within maltodextrin microcapsules using electrospray processing was investigated. By choosing an appropriate polarity of the DC electric field, the surface charged probiotic cells were localized either in the core or towards the surface of the capsule, as visualized using confocal microscopy. Negatively charged probiotic cells encapsulated using a negative polarity on the electrospraying nozzle, were ‘organized’ mostly in the core of the microcapsules. The organization of the cells affected the evaporation of the solvent (water) and subsequently the glass transition temperature (Tg) of the electrosprayed microcapsules. Moreover, the viability of the encapsulated cells was significantly improved for up to 2 weeks of storage at 25 °C and 35% RH when the cells were located at the core of the microcapsules compared to case where the probiotics were distributed towards the surface. Overall, this study presents a novel organization process that promotes the stability of the probiotic cells.

Oromucosal administration is an attractive non-invasive route. However, drug absorption is challenged by salivary flow and the mucosa being a significant permeability barrier. The aim of this study was to design and investigate a multi-layered nanofiber-on-foam-on-film (NFF) drug delivery system with unique properties and based on polysaccharides combined as i) mucoadhesive chitosan-based nanofibers, ii) a peptide loaded hydroxypropyl methylcellulose foam, and iii) a saliva-repelling backing film based on ethylcellulose. NFF displays optimal mechanical properties shown by dynamic mechanical analysis, and biocompatibility demonstrated after exposure to a TR146 cell monolayer. Chitosan-based nanofibers provided the NFF with improved mucoadhesion compared to that of the foam alone. After 1 h, >80 % of the peptide desmopressin was released from the NFF. Ex vivo permeation studies across porcine buccal mucosa indicated that NFF improved the permeation of desmopressin compared to a commercial freeze-dried tablet. The findings demonstrate the potential of the NFF as a biocompatible drug delivery system.

Probiotics formulations containing lecithin phospholipids have been shown to extend their viability. However, the protective effect of lecithin and the properties of the mixtures of lecithin and probiotics cells in aqueous media have not been fully documented. The aim of this study was to investigate the interactions between Bifidobacterium animalis ssp. Lactis (Bifido) probiotics and lecithin. The lecithin-Bifido interactions were dependent on lecithin concentration. FTIR and Raman spectroscopy suggested that Bifido cells interacted with lecithin molecules mainly through hydrophobic interactions. At the lecithin concentration of 0.1%.w/v, Bifido lost only about 17% of their viability over 56 days, while free Bifido probiotics lost about 66% of their viability in the same time period. Furthermore, flow cytometer side scatter plots also showed that Bifido-lecithin samples at 0.1 %w/v lecithin, showed the lowest side scatter, indicative of lower cellular stress and a more stable environment to preserve Bifido cells viability over time.

Nicotine replacement therapy (NRT) formulations for oromucosal administration induce a delayed rise in nicotine blood levels as opposed to the immediate nicotine increase obtained from cigarette smoking, this being a shortcoming of the therapy. Here, we demonstrate that α-lactalbumin/polyethylene oxide (ALA/PEO) electrospun nanofibers constitute an efficient oromucosal delivery system for fast-onset nicotine delivery of high relevance for acute dosing NRT applications. In vitro, nicotine-loaded nanofibers showed fast disintegration in water, with a weight loss up to 40% within minutes, and a faster nicotine release (26.1 ± 4.6% after 1 min of incubation) of the loaded nicotine compared to two relevant marketed NRT formulations with a comparable nicotine dose (i.e., 7.9 ± 5.1 and 2.2 ± 0.3% nicotine was released from a lozenge and a sublingual tablet, respectively). Model-fitting of the release data indicated that the release mechanism of nicotine from the hydrophilic nanofibers was possibly governed by more than one type of release phenomena. Remarkably, ex vivo studies using porcine buccal mucosa demonstrated a more efficient permeation of the nicotine released from the nanofibers [flux of 1.06 ± 0.22 nmol/(cm2·min)] compared to when dosing even a ten-fold concentrated nicotine solution [flux of 0.17 ± 0.14 nmol/(cm2·min)]. Moreover, matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI MS) imaging of ex vivo porcine buccal mucosa exposed to nicotine-loaded nanofibers clearly revealed higher amounts of nicotine throughout the epithelium, as well as in the lamina propria and submucosa of the tissue. Our findings suggest that nicotine-loaded ALA/PEO nanofibers have potential as a mucosal, fast-releasing, and biocompatible delivery system for nicotine, which can overcome the limitations of the currently marketed NRTs.

The sublingual mucosa is an attractive route for drug delivery, although challenged by a continuous flow of saliva that leads to a loss of drug by swallowing. It is of great benefit that drugs absorbed across the sublingual mucosa avoid exposure to the harsh environment of the gastro-intestinal lumen; this is especially beneficial for drugs of low physicochemical stability such as therapeutic peptides. In this study, a two-layered hybrid drug delivery system was developed for the sublingual delivery of the therapeutic peptide desmopressin. It consisted of peptide-loaded mucoadhesive electrospun chitosan/polyethylene oxide-based nanofibers (mean diameter of 183 ± 20 nm) and a saliva-repelling backing film to promote unidirectional release towards the mucosa. Desmopressin was released from the nanofiber-based hybrid system (approximately 80% of the loaded peptide was released within 45 min) in a unidirectional manner in vitro. Importantly, the nanofiber–film hybrid system protected the peptide from wash-out, as demonstrated in an ex vivo flow retention model with porcine sublingual mucosal tissue. Approximately 90% of the loaded desmopressin was retained at the surface of the ex vivo porcine sublingual mucosa after 15 min of exposure to flow rates representing salivary flow.

This study investigated the oxidative stability and physical properties of low-fat mayonnaise fortified with electrosprayed zein capsules loaded with fish oil. A high encapsulation efficiency (EE) (83 ± 1%) was achieved in the encapsulates and semi-spherical capsules with rough surface and mean diameter of 2.4 ± 0.7 μm were obtained. The amount of primary oxidation products of the zein capsules did not increase over the storage, even though the initial content was higher compared to neat fish oil. Cryo-SEM images revealed that the capsules remained intact when they were incorporated into a water-based food matrix like mayonnaise. This explained the lower content of hydroperoxides at the end of the storage for the capsule-enriched mayonnaise (Mayo-C) when compared to mayonnaise enriched with neat fish oil (Mayo-F) (2 meq/kg oil vs. 6 meq/kg oil, respectively). Even though, volatile compounds from the secondary oxidation of omega-3, such as 2-ethylfuran and 1-penten-3-one were found in higher amounts in Mayo-F, a higher overall increase in all other secondary oxidation products was observed in Mayo-C. This increase was attributed to the formation of oxidation volatile compounds from the zein material, together with the oxidation of un-encapsulated fish oil droplets. Moreover, Mayo-C presented higher viscosity and droplet size than Mayo-F, which also increased during storage, although no further alterations of the emulsion like creaming were observed. Overall, these findings indicate the benefits of using zein as hydrophobic shell material for the development of omega-3 loaded-electrosprayed capsules intended to the enrichment of water-based food matrices when compared to the use of hydrophilic wall materials.

The oxygen permeability and oxidative stability of fish oil-loaded electrosprayed capsules were studied by Electron Spin Resonance (ESR). Electrosprayed capsules with dextran as main biopolymer showed a significantly faster broadening (ΔHpp) of 16-doxyl-stearate ESR spectrum when compared to glucose syrup capsules. This finding indicates a higher oxygen permeability of dextran capsules than glucose syrup capsules, which is explained by a reduced average free volume in the glucose syrup matrix than in the dextran shell. Moreover, glucose syrup capsules showed a significantly lower increase in the peak-to-peak amplitude of N-tert-butyl-α-phenylnitrone (PBN) ESR spectrum during storage when compared to dextran capsules. This implies a higher oxidative stability of glucose syrup capsules than dextran capsules, which correlated well with the lower oxygen permeability of the former. These results indicated the importance of the oxygen barrier properties of the wall materials when encapsulating long chain omega-3 polyunsaturated fatty acids by electrospraying.

Functional nano-microfibers and capsules developed using electrohydrodynamic (EHD) processing methods for the encapsulation of probiotics are reviewed. The properties of the polysaccharides, proteins, or hybrids compounds utilized for probiotics encapsulation, and the characteristics of the tailor-made matrices by EHD, facilitate high encapsulation and long-term viability of cells. The ability of the electrospun fibers and electrosprayed capsules to incorporate other functional compounds (e.g. prebiotics), and their effectiveness to promote the targeted delivery and the survival of the encapsulated probiotics cells under gastrointestinal track conditions, are also discussed.

3D scaffolds are in the center of attention for tissue engineering applications. Whilst many studies have focused on the biological properties of scaffolds, less attention has been paid to meeting the biomechanics of the target tissues. In this work, we show how using the same original biomaterial, but different fabrication techniques can lead to a broad range of structural, mechanical, and biological characteristics. Starting with silk fibroin filament as our base biomaterial, we employed electrospinning, film casting, and weft knitting as different scaffold fabrication techniques. Among these three, the weft knit scaffold showed outstanding cell-scaffold interaction including full 3D cell attachment, complete cell coverage around individual filaments, and in-depth cell infiltration. Post-fabrication degumming of silk filament yarns resulted in more bulky and less open pores for the silk fibroin knit scaffold. The decreased pore size after degumming of knit scaffold alleviated the need to in-advance pore filling (a requisite for increasing cell adhesion in a typical knit scaffold having big pores). From a mechanical viewpoint, the weft knit scaffold shows the highest mechanical strength alongside with far better extensibility. Interestingly, the silk filament weft knit scaffold (in the course direction) was 100 and 1000 times more compliant than silk fibroin film and electrospun web, respectively. The observed effect of material type and fabrication technique highlights the suitability of silk fibroin weft-knit scaffolds for the regeneration of load-bearing soft tissues such as urine bladder.

Mucoadhesive chitosan-based electrospun nanofibers are promising candidates for overcoming challenges associated with sublingual drug delivery, yet studies focusing on evaluating the mucoadhesive properties of nanofibers for sublingual administration are limited. The aim was to elucidate the mucoadhesive properties of chitosan/polyethylene oxide (PEO) nanofibers focusing on how the degree of deacetylation (DDA, 53–96 %) of chitosan influenced their morphological and mucoadhesive properties. The mechanism of mucoadhesion was explained by the intermolecular interactions of chitosan with mucin from bovine submaxillary glands using quartz-crystal microbalance with dissipation monitoring and by adhesion of the nanofibers to ex vivo porcine sublingual mucosa. An increase in chitosan DDA improved the morphological stability of the nanofibers in water, but did not contribute to altered mucoadhesive properties. This study demonstrates excellent mucoadhesive properties of chitosan/PEO nanofibers and shows that the strong mucoadhesiveness of the nanofibers is attributed to their swelling ability.

Publisher's version (útgefin grein), The critical role of indigenous crops in the socioeconomic growth of developing nations has necessitated calls for accelerated exploitation of staples. Cocoyam, Xanthosoma sagittifolium, is food for over 400 million people worldwide and is the most consumed aroid in West Africa. However, it remains an underexploited food resource. This study reviews existing literature and also makes use of primary data from interviews with indigenous cocoyam farmers, processors, consumers, and cocoyam scientists in the research Institutes of Ghana, to provide insight into existing nomenclature of the species, indigenous knowledge on food uses, nutritional value, and potential novel food applications of cocoyam. Adaptable technologies in conformity to new trends in food science that could be employed for in‐depth molecular studies and further exploitation of the crop are also discussed. It is envisaged that the provided information would contribute to global efforts aimed at exploiting the full potential of indigenous crops for sustainable food and nutrition security., DANIDA (12-PO8-GH): Strengthening Roots and Tuber Value Chains in Ghana

Hydrogels mineralized with calcium phosphate (CaP) are increasingly popular bone regeneration biomaterials. Mineralization can be achieved by phosphatase enzyme incorporation and incubation in calcium glycerophosphate (CaGP). Gellan gum (GG) hydrogels containing the enzyme phytase and chitosan oligomer were mineralized in CaGP solution and characterized with human osteoblast-like MG63 cells and adipose tissue-derived stem cells (ADSC). Phytase induced CaP formation. Chitosan concentration determined mineralization extent and hydrogel mechanical reinforcement. Phytase-induced mineralization promoted MG63 adhesion and proliferation, especially in the presence of chitosan, and was non-toxic to MG63 cells (with and without chitosan). ADSC adhesion and proliferation were poor without mineralization. Chitosan did not affect ADSC osteogenic differentiation.

Nowadays, there is an aggressive rate in consumption of noodles and pasta products throughout the world. Consumer acceptability and preference of these functional products can be promoted by the discovery of novel knowledge to improve their formulation and quality. The development of fortified-formulations for noodles and pasta products based on microbial transglutaminase (MTGase) can guarantee the shelf life extension with minimum quality losses. The current review focuses on recent trends and future prospects of MTGase utilization in the structural matrix of noodles and pasta products and represents the quality changes of cooking loss, texture, microstructure, color and sensory attributes of the MTGase-incorporated products. Digestibility, nutritional and health aspects of the MTGase-enriched formulations are also reviewed with a vision toward physical functions and safety outcomes of MTGases isolated from new microbial sources. The high potential of MTGase in developing commercial noodles and pasta products is successfully demonstrated. MTGase by modifying the crystallinity or molecular structure via covalent crosslinks between protein molecules strengthens the doughs stability and the textural characteristics of final products with the low- or high-protein flour. Compared with the control samples, the MTGase-supplemented products indicate slower digestion rates and better sensory and cooking properties without any remarkable color instability.

In this study, the anionic polysaccharide Xanthan gum (X) was mixed with positively charged Chitosan oligomers (ChO), and used as building blocks, to generate novel nanofibers by electrostatic self-assembly in aqueous conditions. Different concentrations, ionic strength and order of mixing of both components were tested and observed to affect the diameter, which ranged from 100 to 500 nm, and morphology of the self-assembled nanofibers. The release of diclofenac, as model drug, from self-assembled xanthan-chitosan nanofibers was demonstrated, suggesting that these nanostructures can be used in applications within life sciences such as drug delivery.

The interfacial rheological properties of solutions of β-lactoglobulin (BLG), as a model food compound, mixed with bovine submaxillary mucin (BSM), a major salivary protein, have been investigated. Time, frequency, stress sweep and flow measurements have been performed at different pHs (7.4, 5.0 and 3.0), to investigate the air/water interfacial properties. All protein layers (BLG, BSM, and BLG-BSM mixtures) formed an elastic network at the air/water interface with low frequency dependence of the interfacial modulus. The results indicated that BLG moves faster as smaller molecule than mucin, and dominate the surface adsorption and the network formation for the BLG-BSM mixtures. Moreover, BLG-BSM protein mixtures exhibited interfacial properties with lower elastic and viscous moduli than BLG, as a result of competitive displacement of BLG proteins with BSMs from the interface. It is suggested that hydrophobic patches of BSM can be imbedded into the BLG monolayer as driven by a strong hydrophobic interaction with air and disrupt the cohesive assembly of BLG, whereas the hydrophilic (negatively charged) parts of the BSM chain are protruding from the interface towards the bulk water.

The encapsulation of fish oil in carbohydrate-based nanomicrostructures obtained by electrohydrodynamic processing was investigated. Solutions of pullulan 200 kDa (15 wt%) and dextran 70 kDa (25 wt%) presented appropriate properties (viscosity, surface tension and conductivity) to allow the formation of nano-microfibers and nano-microcapsules, respectively. Although dextran 70 kDa exhibited antioxidant properties in solution, their capsules produced at lab and pilot-plant scales showed a low oxidative stability both with emulsified and neat oil. Phase separation of solution and opened capsules indicated a poor interaction between dextran and fish oil, which suggested that further optimization of the electrospraying solution is necessary. On the contrary, pullulan solutions were optimized to work even at pilot-plant scale. In this case, in spite of the prooxidant effect of pullulan in solution, oxidatively stable pullulan fibers (PV = 12.3 ± 0.9 meq O2/kg and 15.5 ± 5.1 ng/g of 1-penten-3-ol) were obtained when oil was incorporated as neat oil and when producing batches during short time (30 or 10 min). This superior oxidative stability when compared to fibers with emulsified oil is mainly attributed to a higher fish oil entrapment and to the location of the oil in large bead-structures with a reduced specific surface area. These results indicated the feasibility of producing omega-3 nanodelivery systems by encapsulating fish oil in pullulan nano-microfibers using electrospinning processing.

To effectively promote the industrial utilization of cocoyam (Xanthosoma sagittifolium) roots for enhanced food sustainability and security, there is a need to study their molecular, mechanical and physicochemical properties in detail. The physicochemical and textural characteristics of the red and white varieties of cocoyam roots were thus analysed by low field nuclear magnetic resonance relaxometry, multispectral imaging, uniaxial compression testing, and relevant physicochemical analysis in the current study. Both varieties had similar dry matter content, as well as physical and mechanical properties. However, up to four fast-interacting water populations were observed in the roots, dependent on the root variety and their degree of gelatinization during cooking. Changes in the relaxation parameters indicated weak gelatinization of starch at approximately 80 °C in both varieties. However, shorter relaxation times and a higher proportion of restricted water in the white variety indicated that this variety was slightly more sensitive towards gelatinization. A strong negative correlation existed between dry matter and all multispectral wavelengths >800 nm, suggesting the potential use of that spectral region for rapid analysis of dry matter and water content of the roots. The small, but significant differences in the structural and gelatinization characteristics of the two varieties indicated that they may not be equally suited for further processing, e.g. to flours or starches. Processors thus need to choose their raw materials wisely dependent on the aimed product characteristics. However, the spectroscopic methods applied in the study were shown to be effective in assessing important quality attributes during cooking of the roots.

Mucins are long glycoprotein molecules responsible for the gel nature of the mucous layer that covers epithelial surfaces throughout the body. Mucins, as the major salivary proteins, are also important proteins for the food oral processing and digestion. The interactions of salivary mucins and saliva with several food proteins and food protein emulsions, as well as their functional properties related to the food oral processing were reviewed in this paper. The target food proteins of focus were whey proteins (lactoferrin and beta-lactoglobulin) and non-whey proteins (casein, gelatin, galectin/lectin, and proline-rich proteins). Most of the studies suggest that electrostatic attraction (between positively charged food proteins with negatively charged moieties of mucin mainly on glycosylated region of mucin) is the major mode of interaction between them. On the other hand, casein attracts the salivary proteins only via non-covalent interactions due to its naturally self-assembled micellar structure. Moreover, recent studies related to β-lactoglobulin (BLG)-mucin interactions have clarified the importance of hydrophobic as well as hydrophilic interactions, such as hydrogen bonding. Furthermore, in vitro studies between protein emulsions and saliva observed a strong aggregating effect of saliva on caseinate and whey proteins as well as on surfactant-stabilized emulsions. Besides, the sign and the density of the charge on the surface of the protein emulsion droplets contribute significantly to the behavior of the emulsion when mixed with saliva. Other studies also suggested that the interactions between saliva and whey proteins depends on the pH in addition to the flow rate of the saliva. Overall, the role of interactions of food proteins and food protein emulsions with mucin/saliva-proteins in the oral perception, as well as the physicochemical and structural changes of proteins were discussed.

Protein-based drug carriers are an interesting alternative to traditional polymeric drug delivery systems due to their intrinsic biocompatibility and biodegradability. Electrospinning of neat proteins holds advantages over electrospinning of protein mixtures, e.g., whey isolates, such as better control of the physicochemical and biological function of the resulting nanofiber-based system. In this study, we explore electrospinning of the isolated milk protein α-lactalbumin (ALA), which is a whey protein with important nutritional and pharmacological properties. Via waterborne electrospinning of ALA with a minimum amount of poly(ethylene oxide) (PEO) as a cospininng polymer, nanofibers of high protein content were successfully produced (up to 84% (w/w)). We demonstrate the ability to produce ALA-based nanofibers with a high degree of tunability in terms of size, stability in water, and mechanical properties. The nanofibers displayed excellent biocompatibility in vitro as the viability of cultured TR146 human buccal epithelium and NIH 3T3 murine fibroblast cells was not influenced by exposure to ALA-based nanofibers. ALA-based nanofibers were loaded with up to 6% (w/w) ampicilin, and the nanofibers were capable of maintaining the activity of the antibiotic after electrospinning and cross-linking. Using such a property of the material, we demonstrate that ampicillin-loaded nanofibers successfully inhibit the growth of Gram-negative bacteria in vitro. Importantly, after treatment with ampicillin-loaded nanofibers, no bacterial regrowth was observed, which indicates that this treatment may clear eventual persisters to ampicillin. Finally, the structural properties of the native functional protein were maintained after release of ALA from the nanofibers. This promotes our platform, not only as a sustainable protein-based drug delivery system, but also as an innovative solid form of ALA for food and pharmaceutical applications.

In this study, a self-powered sensor based on polypyrrole modified melamine aerogel (PPy@MA) was developed and evaluated for monitoring constant humidity and flowing moisture. This sensor has a flexible, ultralight and ultraporous structure, and could generate humidity-induced open-circuit voltage from the concentration gradient of the H+ ions. The PPy@MA humidity sensor generated the voltage of 105 mV, when it was placed in an environment with constant humidity of RH 98%. The response and recovery time was 32 s and 13 s, respectively, as the humidity changed between RH 11% and RH 98%. Furthermore, the sensitivity of the self-powered humidity sensor was evaluated by assessing the moisture changes of the human skin, and the moisture from the human breath.

Novel hybrid hydrogels were formed by adding chitosan (Ch) to phospholipids (P) self-assembled particles in lactic acid. The effect of the phospholipid concentration on the hydrogel properties was investigated and was observed to affect the rate of hydrogel formation and viscoelastic properties. A lower concentration of phospholipids (0.5% wt/v) in the mixture, facilitates faster network formation as observed by Dynamic Light Scattering, with lower elastic modulus than the hydrogels formed with higher phospholipid content. The nano-porous structure of Ch/P hydrogels, with a diameter of 260±20 nm, as observed by cryo-scanning electron microscopy, facilitated the penetration of water and swelling. Cell studies revealed suitable biocompatibility of the Ch/P hydrogels that can be used within life sciences applications.

This study investigates the stabilization of fish oil‐loaded electrosprayed capsules with different natural antioxidants: i) an ethanol extract from the brown alga Fucus vesiculosus; or ii) a combination of δ‐tocopherol and rosemary extract. The seaweed extract enhances the oxidative stability of fish oil‐loaded capsules with dextran as the main biopolymer wall material, but shows a prooxidant effect in fish oil‐loaded capsules having glucose syrup as the main biopolymer. These results can mainly be explained by the higher encapsulation efficiency of dextran capsules when compared to glucose capsules (90 vs. 83–85%), which prevents interaction of metal ions present in the extract with non‐encapsulated oil. On the contrary, the addition of a lipophilic radical scavenger such as δ‐tocopherol in combination with synergistic antioxidants such as carnosic acid and carnosol present in rosemary extract improves the oxidative stability of glucose syrup capsules during 21 day storage, but not when the capsules are added to mayonnaise. Moreover, the capsule‐containing mayonnaise presents a larger droplet size and higher apparent viscosity than mayonnaise enriched with neat fish oil. Both findings indicate that the structure of capsules may have been lost when added to a water‐based food matrix (e.g., mayonnaise) and this requires further investigation. Practical Applications: Novel omega‐3 delivery systems that are more easily dispersed and still maintain their oxidative stability are needed by the food industry. Electrosprayed capsules with a reduced size when compared to spray‐dried capsules, and which are produced without the need of heat for drying emulsions are promising omega‐3 powdered encapsulates. Moreover, the addition of natural antioxidants, commonly used by the industry to further stabilize omega‐3 encapsulates, deserves scientific attention. This study reveals the effect of seaweed antioxidants (e.g., phlorotannins) and commercial natural antioxidants (e.g., δ‐tocopherol and rosemary extract) on the oxidative stability of electrosprayed capsules loaded with fish oil. In addition, the effect of adding the capsules to a food matrix such as mayonnaise has been investigated. Although further development is necessary, these results will open up new strategies to enrich food products with omega‐3 polyunsaturated fatty acids. Fish oil‐loaded electrosprayed capsules stabilized with antioxidants. This study investigates the stabilization of fish oil‐loaded electrosprayed capsules with different natural antioxidants: i) an ethanol extract from the brown alga Fucus vesiculosus; or ii) a combination of δ‐tocopherol and rosemary extract.

Functional phospholipid nano-microfibers and nano-microparticles developedusing electrohydrodynamic processing methods are reviewed. Depending onthe phospholipid concentration the solvent used and the processing conditions,fibers and particles with a range of morphologies, mechanical properties andfunctionalities were observed. The efficacy of electrospun phospholipid fibersas antioxidant, encapsulation, and delivery matrices for bioactive compoundsis also presented.

Xanthan-Chitosan (X-Ch) polysaccharides nanofibers were prepared using electrospinning processing as an encapsulation and delivery system of curcumin (Cu). The X-Ch-Cu nanofibers remained stable in aqueous HBSS medium at pH 6.5 and pH 7.4, mainly due to the ability of oppositely charged xanthan-chitosan polyelectrolytes to form ionically associated electrospun nanofibers. The xanthan-chitosan-curcumin nanofibers were incubated with Caco-2 cells, and the cell viability, transepithelial transport and permeability properties across cell monolayers were investigated. After 24 h of incubation, the exposure of Caco-2 cell monolayers to X-Ch-Cu nanofibers resulted in a cell viability of ∼80%. A 3.4-fold increase of curcumin permeability was observed when the polyphenol was loaded into X-Ch nanofibers, compared to the free curcumin. This increased in vitro transepithelial permeation of curcumin without compromising cellular viability was induced by interactions upon contact between the nanofibers and the Caco-2 cells, leading to the opening of the tight junctions. The results obtained revealed that X-Ch nanofibers can be used for oral delivery applications of poorly water-soluble compounds at the gastrointestinal tract.

Multiple drugs have been proposed for reducing harsh symptoms of human rheumatic diseases. However, a targeted therapy with mild to no side effects is still missing. In this study, we have prepared and tested a series of therapeutic nanoparticles for specific targeting of human neutrophils associated with rheumatoid arthritis. In doing this, a series of citrullinated peptide epitopes derived from human proteins, fibrinogen, vimentin, and histone 3, were screened with regard to specific recognition of neutrophils. The most potent epitope proved to be a mutated fragment of an alpha chain in human fibrinogen. Next, a straightforward synthetic strategy was developed for nanoparticles decorated with this citrullinated peptide epitope and an antisense oligonucleotide targeting disease associated microRNA miR-125b-5p. Our study shows that the nanoparticles specifically recognize neutrophils and knock down miR-125b-5p, with no apparent toxicity to human cells. In contrast to organic dendrimers, chitosan-hyaluronic acid formulations do not activate human innate immune response. Our data proves that the strategy we report herein is effective in developing peptide epitopes for decorating delivery vehicles bearing biological drugs, targeted to a specific cell type.

In this work, polypyrrole (PPy) was in situ polymerized on the surface of TiO2 nanotube array (TiO2 NTA, with average pore diameter of 110 nm and length of 490–750 nm) using cyclic voltammetry method to develop the nanocomposite photoelectrode of PPy@TiO2 NTA. The morphology and the physicochemical properties of the photoelectrode were characterized by SEM, XRD, FTIR, Raman Spectra, and XPS. It was found that the PPy modification enlarged the light adsorption range of the photoelectrode, as well as increased the photocurrent density under UV light irradiation. Furthermore, the performance of PPy@TiO2 NTA photoelectrode was investigated for the decolorization of methylene blue (MB) by means of photocatalytic (PC), electrocatalytic (EC) and photoelectrocatalytic (PEC) degradation. The decolorization rate of MB using the PPy@TiO2 NTA increased by 24.94% and 10.85% under PC and EC conditions, respectively, in comparison with the decolorization rate obtained using pristine TiO2 NTA. The improved decolorization rate of MB was mainly attributed to the separation efficiency of electron-hole pairs originated from TiO2, and the enhanced utilization of visible-light due to the presence of PPy. Furthermore, the decolorization rate of MB under the PEC condition was also significantly improved, compared with the sum of the decolorization rate of PC and EC systems, indicating the synergistic effect of MB oxidation in the photoelectrocatalysis.

Electrospinning of neat chitosan is currently achieved by using strong acids or organic solvents, which limits the use of chitosan nanofibers as biocompatible scaffolds for drug delivery and tissue engineering. The aim was to elucidate the effect of specific acids generally recognized as safe (GRAS) on the properties of electrospun chitosan-based nanofibers. Electrospinning chitosan in dilute acetic acid or succinic acid with polyethylene oxide resulted in white and separated nanofibers, whereas nanofibers electrospun in dilute citric acid were transparent and interconnected. Including succinic or citric acid in the spinning process induced disintegration of the fiber mat after four hours in water, and a concentration-dependent effect on epithelial cell viability. Chitosan nanofibers electrospun in acetic acid maintained their shape and fibrous structure after four hours in water, and showed no effect on cell viability. This study demonstrates that the choice of GRAS acid highly determines the properties of electrospun chitosan nanofibers.

Chitosan particles loaded with the antigen ovalbumin (OVA) and the adjuvant Quil-A were produced by electrospray, using mixtures of water/ethanol/acetic acid as a solvent. Three different chitosans designed as HMC+70, HMC+85, and HMC+90 (called as 705010, 855010, and 905010) were tested and its efficacy to be used in oral vaccine delivery applications was investigated. The morphology, size, and zeta potential of the produced particles were investigated, together with the encapsulation efficiency and release of OVA from the three chitosan formulations. Moreover, the mucoadhesion and cytotoxicity of the chitosan microparticles was examined. All the three formulations with OVA and Quil-A were in the micrometer size range and had a positive zeta potential between 46 and 75 mV. Furthermore, all the three formulations displayed encapsulation efficiencies above 80% and the release of OVA over a period of 80 h was observed to be between 38 and 47%. None of the developed formulations exhibited high mucoadhesive properties, either cytotoxicity. The formulation prepared with HMC+70, OVA, and Quil-A had the highest stability within 2 h in buffer solution, as measured by dynamic light scattering. The electrosprayed formulation consisting of HMC+70 with OVA and Quil-A showed to be the most promising as an oral vaccine system.

This study aimed to develop hybrid electrospun chitosan&ndash, phospholipid nanofibers and investigate the effect of phospholipid (P) content and chitosans (Ch) molecular weights (Mw) and degree of acetylation (DA), on the morphological, mechanical and mucoadhesive properties of the nanofibers. Electrospun Ch/P nanofibers exhibited a smooth and uniform surface with average diameters ranging from 300 to 1000 nm, as observed by scanning electron microscopy (SEM). The average diameter of the nanofibers was observed to increase with the increase of the Mw and degree of deacetylation of Ch, and phospholipid content. The elastic and adhesive properties of the nanofibers were determined by atomic force microscopy, and displayed higher values for higher Mw and lower DA Ch used. The elastic modulus of electrospun Ch/P hybrid fibers determined for the different conditions tested was found to be in the range of 500 and 1400 MPa. Furthermore, electrospun Ch/P nanofibers displayed mucoadhesive properties expressed by the work of adhesion calculated after the compression of the nanofibers against a section of pig small intestine. Our results showed that the increase in phospholipid content and DA of Ch decrease the work of adhesion, while the increase of Mw resulted in slightly higher work of adhesion of the nanofibers.

Among the food wastes, the dairy effluent (DE) is considered to be the most polluting one because of the large volume of wastewater generated and its high organic load. Photocatalytic degradation of DE and organic dye methylene blue (MB) was studied using Zinc oxide nanofibers (ZnO NFs), Nickel oxide nanofibers (NiO NFs) and composite Zinc oxide–Nickel oxide nanofibers (ZnO–NiO NFs). These nanomembranes were characterized in SEM, TEM, XRD and UV studies. The pristine nanofiber membranes were smooth and continuous, with an average diameter of about 400 nm, and held their nanofibrous morphology even after calcination of 600 °C and more than 3 h of photocatalytic degradation of DE and MB dye. The ZnO NFs and NiO NFs were effective materials for degradation of DE and MB dye. NiO NFs and ZnO NFs showed a maximum degradation of 70% and 75% in DE and 50% and 60% in MB dye respectively, after 3 h. The significant enhancement of degradation in the composite ZnO–NiO NFs is attributed to the photoactivity of material under visible light irradiation. The composite ZnO–NiO NFs eliminated 40% of DE and 65% of MB dye, after 1 h and maximum degradation of 80% DE after 3 h and 100% MB dye after 90 min. Overall, this study also shows that the nanofibrous morphology strongly enhances the surface activity of the ZnO–NiO photocatalyst when utilized to degrade DE and MB dye at room temperature.

The efficacy of chitosan (CS) to be used as drug delivery carrier has previously been reported. However, limited work has been pursued to produce stable and mucoadhesive CS electrosprayed particles for oral drug delivery, which is the aim of this study. Various CS types with different molecular weight (MW), degree of deacetylation (DD), and degree of polymerization (DP) were assessed. In addition, the effect of the solvent composition was also investigated. Results showed that stable CS electrosprayed particles can be produced by dissolving 3% w/v of low MW CS in mixtures of aqueous acetic acid and ethanol (50/50% v/v). The stable CS particles displayed diameters of approximately 1 μm as determined by dynamic light scattering. The zeta potential of these particles was found to be approximately 40 mV confirming the mucoadhesion properties of these CS electrosprayed particles and its potential to be used as drug delivery carrier.

Poly(ɛ‐caprolactone) (PCL) is explored in tissue engineering (TE) applications due to its biocompatibility, processability, and appropriate mechanical properties. However, its hydrophobic nature and lack of functional groups in its structure are major drawbacks of PCL‐based scaffolds limiting appropriate cell adhesion and proliferation. In this study, silk fibroin (SF) was immobilized on the surface of electrospun PCL nanofibers via covalent bonds in order to improve their hydrophilicity. To this end, the surface of PCL nanofibers was activated by ultraviolet (UV)–ozone irradiation followed by carboxylic functional groups immobilization on their surface by their immersion in acrylic acid under UV radiation and final immersion in SF solution. Furthermore, morphological, mechanical, contact angle, and Attenuated total reflection‐ Fourier transform infrared (ATR‐FTIR) were measured to assess the properties of the surface‐modified PCL nanofibers grafted with SF. ATR‐FTIR results confirmed the presence of SF on the surface of PCL nanofibers. Moreover, contact angle measurements of the PCL nanofibers grafted with SF showed the contact angle of zero indicating high hydrophilicity of modified nanofibers. In vitro cell culture studies using NIH 3T3 mouse fibroblasts confirmed enhanced cytocompatibility, cell adhesion, and proliferation of the SF‐treated PCL nanofibers.

Asolectin phospholipid nano-microfibers were prepared using electrospinning processing. The asolectin fibers were studied by scanning electron microscopy, and the fiber morphology was found to be strongly dependent on the phospholipid concentration and the solvents used. The solvents studied were chloroform : dimethylformamide (CHCl3 : DMF, 3 : 2 v/v), isooctane, cyclohexane and limonene, producing phospholipid fibers with average diameters in the range of 2.57 ± 0.59 μm, ∼3–8 μm, ∼4–5 μm and 14.3 ± 2.7 μm, respectively. The diameter of asolectin electrospun fibers does not follow the theoretically predicted value of ∼0.35 μm because of the intermolecular aggregation between the reverse micelles formed in the highly concentrated asolectin solutions. However, when co-axial solvent electrospinning was applied, where the outer needle contains a pure solvent and the inner needle contains the asolectin solution in CHCl3:DMF, a substantial reduction in the average fiber diameter was observed. In particular, the average diameter of the fibers when DMF (a solvent with a high dielectric constant) was used as a sheath solvent was reduced by a factor of about 7 and was at the nano-size range, as theoretically predicted. The dielectric constant of the solvents had a strong influence on the jet split properties and affected the morphology of the electrospun asolectin fibers.

A new strategy for fabricating water-dispersible AgInS2 quantum dots (QDs) with bright near-infrared (NIR) emission is demonstrated. A type of multidentate polymer (MDP) was synthesized and utilized as a compact capping ligand for the AgInS2 QDs. Using silver nitrate, indium acetate and sulfur–hydrazine hydrate complex as the precursors, MDP-capping AgInS2 QDs were synthesized in aqueous solution at room temperature. Characterization indicates that the MDP-capping AgInS2 QDs are highly photoluminescent in NIR window and possess good photostability. Also, the QDs are stable in different media and have low cytotoxicity. Nude mice photoluminescence imaging shows that the MDP-capping AgInS2 QDs can be well applied to in vivo imaging. These readily prepared NIR fluorescent nanocrystals have huge potential for biomedical applications.

Genipin is increasingly used as a crosslinking agent for chitosans due to its low cytotoxicity as a naturally occurring extract of the plant Gardenia jasminoides. Genipin reacts with the primary amino groups of chitosan to form blue hydrogels. We studied the gelation kinetics of different chitosans varying in their properties (molar mass 34 000-213 000 g mol-1, degree of acetylation 9-20%) and genipin in detail. We found that critical sol-gel transition times obtained from dynamic light scattering were in good agreement with the results obtained by small deformation oscillatory rheometry and microviscosimetry at high concentrations of chitosan. However, at below critical concentrations, we found a second regime of gelation that followed the same Ross-Murphy's gelation kinetics. The macroscopic appearance of these samples was a suspension of weak gel-like particles that were sensitive to mechanical forces. We believe that the material is a mesoscopic gel, as described for other polymers. To the best of our knowledge, this is the first time that this phenomenon has been described for the gelling system of chitosan and genipin.

Regenerative medicine for reconstructive urogenital surgery has been widely studied during the last two decades. One of the key factors affecting the quality of bladder regeneration is the mechanical properties of the bladder scaffold. Insight into the biomechanics of this organ is expected to assist researchers with functional regeneration of the bladder wall. Due to extensive similarities between human bladder and porcine bladder, and with regard to lack of comprehensive biomechanical data from the porcine bladder wall (BW), our main goal here was to provide a thorough evaluation on viscoelastic properties of fresh porcine urinary BW. Three testing modes including Uniaxial tensile, Ball-burst (BB) and Dynamic Mechanical Analyses (DMA) were applied in parallel. Uniaxial tests were applied to study how different circumferential and longitudinal cut-outs of lateral region of BW behave under load. DMA was used to measure the viscoelastic properties of the bladder tissue (storage and loss modulus) tested in a frequency range of 0.1 to 3 Hz. BB was selected as a different technique replicating normal physiological conditions where the BW is studied in whole. According to uniaxial tests, the anisotropic behavior of bladder was evident at strain loads higher than 200%. According to DMA, storage modulus was found to be consistently higher than loss modulus in both directions, revealing the elasticity of the BW. The stress-strain curves of both uniaxial and BB tests showed similar trends. However, the ultimate stress measured from BB was found to be around 5 times of the relevant stress from uniaxial loading. The ultimate strain in BB (389.9 ± 59.8) was interestingly an approximate average of longitudinal (358 ± 21) and circumferential (435 ± 69) rupture strains. Considering that each testing mode applied here reveals distinct information, outcomes from the combination of the three can be considered as a helpful data-base to refer to for researchers aiming to regenerate the bladder.