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Our regard to the use of chitin as a material has drastically changed since its discovery.

[EN] The extraction of nanochitin from marine waste has attracted great industrial interest due to its unique properties, namely biodegradability, biocompatibility and as a functional reinforcing agent. Conventional acid hydrolysis isolation of nanochitin requires high temperatures and acid concentration, time and energy. Herein, for the first time, microwave irradiation method was used as an eco-friendly approach to isolate nanochitin from different sources. The isolation conditions were optimized through an experimental Box-Behnken design using surface response methodology. The data showed optimal conditions of 1 M HCl, 10.00 min and 124.75 W to obtain lobster nanocrystals; 1 M HCl, 14.34 min and 50.21 W to obtain shrimp nanocrystals; and 1 M HCl, 29.08 min and 54.08 W to obtain squid pen nanofibres, reducing time and HCl concentration. The obtained isolation yields where of 85.30, 79.92 and 80.59 % for lobster, shrimp and squid, respectively. The morphology of the nanochitins was dependent of the chitin origin, and the lengths of the nanochitins were of 314.74, 386.12 and > 900 nm for lobster, shrimp and squid pen, respectively. The thermal stability of the ensuing nanochitins was maintained after treatment. The results showed that nanochitin could be obtained by using an eco-friendly approach like microwave irradiation. The authors would like to thank the Basque Government (scholarship of young researchers training and project IT1008-16) for supporting financially this research and their gratitude for technical and human support provided by SGIker (UPV/EHU/ERDF, EU). S.C.M.F. is the recipient of an E2S UPPA Research Partnership Chair (MANTA: Marine Materials) supported by the “Investissements d’Avenir” French program managed by ANR (ANR-16-IDEX-0002), the R ́egion Nouvelle-Aquitaine and the Communaut ́e d’Agglom ́eration du Pays Basque, France.

The current drive for sustainability demands recyclable matrices for composite materials. Vitrimers combine thermoset properties with reprocessability, but their mechanical performance in highly loaded applications, for instance, composites for aeronautics, is still to be demonstrated. This work presents the complete mechanical characterization of a new vitrimer reinforced with carbon fiber. This vitrimer formulation consists of functional epoxy groups and a new dynamic disulfide crosslinks-based hardener. The testing campaign for the vitrimer composites encompassed tension, compression, interlaminar shear strength (ILSS), in-plane shear (IPS), open-hole tension (OHT) and compression (OHC), filled-hole compression (FHC) and interlaminar fracture toughness tests under mode I and II. Test conditions included room temperature and high temperature of 70 °C and 120 °C, respectively, after moisture saturation. Tension and flexural tests also were applied on the neat vitrimer resin. The results compared well with those obtained for current aeronautic materials manufactured by Resin Transfer Molding (RTM). The lower values observed in compression and ILSS derived from the thermoplastic veils included as a toughening material. This work demonstrates that the vitrimer formulation presented meets the requirements of current matrices for aeronautic-grade carbon-reinforced composites This work was financially supported by the EU Horizon 2020 research and innovation project AIRPOXY with grant agreement 769274 under the H2020-MG-2017-Two-Stage call. J. Costa acknowledges the support of the Spanish MICINN, through the project RTI2018-097880-B-I00

Kaya, Murat ( Aksaray, Yazar ), Chitosan samples from two mushroom species (Boletus bovinus, Laccaria laccata) were obtained and characterized by viscosimetry, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), elemental analyses (EA), nuclear magnetic resonance spectroscopy (13C NMR), X-ray diffraction (XRD) and thermogravimetric (TGA) analyses. Properties of the fungal chitosan samples were compared to commercial low-molecular weight chitosan, crustacean chitosan (Cervimunida johni) and chitosan obtained from an insect (Hilobius abietis). Additionally, the cytotoxic properties of chitosan in vitro on cancerous hepatoma and non-cancerous ovary cells cultivated on films with different chitosan concentrations was evaluated. As a conclusion, this study clearly revealed that low-molecular weight chitosan films and solutions with high degree of deacetylation can act cytotoxically on both tumor MH-22A and normal CHO cells in vitro. Consequently, this work may be useful for further investigations of natural anticancer products in medical areas.

[EN] The preparation polyelectrolytes based on crosslinked poly(vinyl alcohol) (PVA) and chitosan (CS) was considered as a feasible alternative to develop highly functionalised, cost-effective and eco-friendly membranes for proton exchange fuel cell technologies. CS/PVA-based membranes were combined with sulfosuccinic acid (SSA) as crosslinking and sulfonating agent, and glycerol (GL) to promote flexibility and favour their manageability. The chemical structure, the thermo-oxidative behaviour, the ethanol uptake, the electric, the proton conductivity, and the performance in direct ethanol fuel cell (DEFC) were assessed. In general, all the CS/PVA-based polyelectrolytes showed a synergetic increase of thermo-oxidative stability, appropriate absorption and diffusion of ethanol and good proton conductivity, suitable for the typical service conditions of fuel cells. The GL in the membranes reacted with SSA, reduced the ethanol absorption, diffusion coefficient and proton conductivity, but acted as a plasticiser that increased the ductile manageability of the polyelectrolytes to be mounted on the membrane-electrode assembly (MEA). Higher presence of CS and higher the proportion of GL in the polyelectrolyte, improved the material performance in the DEFC. In particular, the crosslinked polyelectrolyte 40CS/PVA/SSA/20GLwith a 40 %wt. of CS referred to PVA, and a 20 %wt. of GL referred to CS, showed a suitable behaviour in the DEFC test, with a maximum value of power density of 746 mW·cm-2., The Spanish Ministry of Economy, Industry and Competitiveness is acknowledged for the projects ENE2017-86711-C3-1-R and UPOV13-3E-1947. The Spanish Ministry of Education, Culture and Sports is thanked for the pre-doctoral FPU grant for O. Gil-Castell (FPU13/01916)

WOS: 000472685700071, PubMed: 31022490, In the current study, chia mucilage composite films with starch nanocrystals (3% and 6%) were produced. The films were analyzed physicochemically (FT-IR, AFM, TGA, DSC), mechanically (Tensile strength and contact angle) and biologically (antimicrobial, antioxidant and cytotoxicity) properties. The incorporation of starch nanocrystals was confirmed through FT-IR spectra showing broad OH peak and C=O stretching and shift in N-H bending vibrations to the lower wave number. Starch nanocrystals enhanced (control 287.23 degrees C, film with 3% SNC 286.91 degrees C and film with 6% mucilage 289.41 degrees C) the thermal properties of the composite films. The Young Modulus of the film showed an increase after the incorporation of starch nanocrystals due to the strong interaction between mucilage and nanocrystals. On the other hand, the overall hydrophobicity of mucilage composite film decreased due to the hydrophilic nature of cornstarch nanocrystals. mu assay for cell proliferation revealed significant inhibition of cancer cell (HepG2) lines and exhibits a very low inhibition of epithelial cell line (Vero). Starch nanocrystals enhanced the antibacterial and antioxidant (threefold increase compare to control) properties of mucilage composite films. Mucilage-SNC composite films could be a good therapeutic gain for control and directed drug delivery, food packaging, food coating. (C) 2019 Elsevier B.V. All rights reserved.

Traditional crosslinked aero grade epoxy resins have excellent thermal-mechanical properties and solvent resistance, but they cannot be remolded, recycled, or repaired. Vitrimers can be topologically rearranged via an associative exchange mechanism, endowing them with thermoplasticity. Introducing dynamic bonds into crosslinked networks to obtain more sustainable thermosets is currently an interesting research topic. While recent research into vitrimers has indicated many advantages over traditional thermosets, an important shortcoming has been identified: susceptibility to creep at service temperature due to the dynamic bonds present in the network. In addition, designing aero grade epoxy vitrimers (similar to RTM6 resin) still remains a challenge. Herein, low creep aero grade epoxy vitrimer with thermal and mechanical properties similar to those of aero grade epoxy resins and with the ability to be recyclable, repairable, and reprocessable, has been prepared. In this manuscript, we demonstrate that aero grade epoxy vitrimer with reduced creep can be easily designed by the introduction of a certain fraction of permanent crosslinks, without having a negative effect on the stress relaxation of the material. Subsequently, the mechanical and relaxation properties were investigated and compared with those of classical aero grade epoxy resin. A high Tg (175 C) epoxy vitrimer was obtained which fulfilled all mechanical and thermal specifications of the aero sector. This work provides a simple network design to obtain aero grade epoxy resins with excellent creep resistance at elevated temperatures while being sustainable. This research has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 769274, “AIRPOXY”.

WOS: 000425202600033, Chitosan-based edible films were prepared by supplementing Berberis crataegina DC.'s seed oil and fruit extract into chitosan matrix. The produced films have characterized both physiochemically (SEM, DSC, FT-IR, UV-vis, contact angle and mechanical analysis) and biologically (anti-quorum sensing, antimicrobial and antioxidant). Chitosan-fruit extract film revealed higher thermal stability, antioxidant, antimicrobial and anti-quorum sensing activity compared to other films. Addition of B. crataegina's seed oil and fruit extract into the chitosan film notably decreased the UV-vis transmittance but ameliorate the tensile strength values. Hydrophobicity of the chitosan-seed oil film was observed to be higher (92.64 +/- 4.17) than chitosan-control film (84.67 +/- 1.50) while chitosan-fruit extract film exhibited slightly lower hydrophobicity (73.82 +/- 7.42) than chitosan film. The overall high thermal stability, antioxidant and antimicrobial activity of chitosan-fruit extract film revealed that B. crataegina's fruit extract can be used as an effective ingredient for the production of the edible film with enhanced physicochemical and biological properties.

WOS: 000423406900004, Methanol extracts of stem, leaf, and seed obtained from Pistacia terebinthus which are rich in phenolic compounds were used for the first time to produce chitosan-based antioxidative and antimicrobial films. All the produced films were characterized by FT-IR, TGA, DSC, SEM, contact angle measurements, and UV-Vis spectroscopy and mechanically. As was expected, incorporation of the plant extracts into chitosan films enhanced the antioxidant and antimicrobial activities effectively. Also, the elasticity of chitosan-seed and chitosan-stem films was improved. The eco-friendly nature of the produced blend films was determined through soil and water degradation analyses. All these findings lead to the conclusion that the produced blend films with Pistacia terebinthus extracts can be applied as alternative food packaging material.

WOS: 000396955500019, PubMed: 28267493, In previous studies, chitin-based films were produced from chitin nanofibers in dust form and fully characterized. However, chitin films naturally present.in many organisms have not been isolated and characterized. Herein, structurally intact chitin films were successfully extracted from the dorsal pronoturn and the wing of cockroach. Despite using the same extraction procedure, important differences were observed. Especially, hydrophobicity, transparency, antifungal and antibacterial biofilm activities of wing chitin film were recorded notably higher than those of chitin film from the dorsal pronotum. However, better mechanical properties were observed for chitin film from the dorsal pronotum. Notably, among the tested bacteria, two common pathogens could not form biofilms on the surface of the films. This study clearly demonstrated natural chitin films obtained from an insect can provide a new perspective to chitin-based applications where chitin films with high thermal stability, transparency, resistance to bacterial biofilm formation and antifungal activity are needed. (C) 2017 Elsevier Ltd. All rights reserved.

*Koç, Behlül ( Aksaray, Yazar ) *Akyüz, Lalehan ( Aksaray, Yazar ) *Çakmak, Yavuz Selim ( Aksaray, Yazar ) *Kaya, Murat ( Aksaray, Yazar ), A fungal extract obtained from an edible species (Tricholoma terreum) was used to produce chitosan-based films. Fungal extracts were analyzed using HPLC and chitosan-based films were characterized with FT-IR, SEM, DSC and TGA analysis. High phenolic content was found in the fungal extracts using HPLC. FT-IR results showed that fungal extracts were successfully added into the chitosan films. The addition of fungal extract increased elasticity, hydrophobicity and antioxidant and antimicrobial activity of the chitosan films. Additionally, anti-quorum sensing and antimicrobial activities of chitosan-fungal extract films were found to be much higher than gentamicin (a commonly used antibiotic). However, incorporation of extracts into chitosan films decreased transparency and thermal stability. All these results suggested that chitosan-fungal extract films might be beneficially used to improve food packaging technology.

Copper (Cu (II)) is one of the most toxic heavy metals usually found in the environment. Thus its removal from aqueous waste streams is an important issue in nowadays. The present work focuses on the comparison of the copper adsorption on chitin-based adsorbents, i.e. chitin (CH), chitosan (CS) and chitosan- ethylenediaminetetra-acetic acid (CS-EDTA). Chitin derivatives are carbohydrate materials well known to remove heavy metal ions from aqueous solutions. The effects of contact time, initial concentration, the temperature, pH, and mass of the adsorbent in the adsorption process were studied. The adsorption isotherms were well simulated by Langmuir and Freundlich models. The maximum adsorption capacity of CH, CS and CS-EDTA at 25 °C, pH 7.0 was found to be 58, 67 and 110 mg g−1, respectively. Thermodynamic parameters of adsorption processes such as Gibb's free energy (ΔG0), standard enthalpy (ΔH°) and entropy (ΔS0) were also calculated. The results showed that the studied materials could be used as effective adsorbents for removal of copper from water.

Triacetate citrate plasticized poly lactic acid and its nanocomposites based on cellulose nanocrystals (CNC) and chitin nanocrystals (ChNC) were prepared using a twin-screw extruder. The materials were compression molded to films using two different cooling rates. The cooling rates and the addition of nanocrystals (1 wt%) had an impact on the crystallinity as well as the optical, thermal and mechanical properties of the films. The fast cooling resulted in more amorphous materials, increased transparency and elongation to break, (approx. 300%) when compared with slow cooling. Chitin nanocomposites were more transparent than cellulose nanocomposites; however, microscopy study showed presence of agglomerations in both materials. The mechanical properties of the plasticized PLA were improved with the addition of a small amount of nanocrystals resulting in PLA nanocomposites, which will be further evaluated for film blowing and thus packaging applications.

Bionanocomposite films prepared with melt compounding and film blowing were evaluated for packaging applications. The nanocomposite masterbatch with 75 wt.% polylactic acid (PLA), 5 wt.% chitin nanocrystals (ChNCs) and 20 wt.% glycerol triacetate plasticizer (GTA) was melt compounded and then diluted to 1 wt.% ChNCs with PLA and polybutylene adipate-co-terephthalate (PBAT) prior to film blowing. The morphological, mechanical, optical, thermal and barrier properties of the blown nanocomposite films were studied and compared with the reference material without ChNCs. The addition of 1 wt.% ChNCs increased the tear strength by 175% and the puncture strength by 300%. Additionally, the small amount of chitin nanocrystals affected the glass transition temperature (Tg), which increased 4 °C compared with the reference material and slightly enhanced the films degree of crystallinity. The chitin nanocomposite also had lower fungal activity and lower electrostatic attraction between the film surfaces; leading to easy opening of the plastic bags. The barrier and optical properties as well as the thermal degradation of the films were not significantly influenced by the addition of chitin nanocrystals. Keywords: Nanocomposite, Extrusion, Nanocrystals, Mechanical properties, Thermal properties, Film blowing

Dyes are classified as one of the major pollutants of water. They have negative impacts not only on environment but also on human health. In fact, wastewater that contains these harmful substances requires many types of treatments. Therefore, alternative methods and adsorption agents are needed. Herein, we propose to evaluate the decolorization of methylene blue (MB) and methyl orange (MO) as two models of soluble dyes from water using chitin and chitosan-graft-polyacrylamide. Furthermore, the applicability of these biomacromolecules as alternative adsorption agents, their sticking probability and desorption were also examined. Experimental parameters such as dye concentration, contact time, pH solution, adsorbent dosage and temperature were thoroughly examined for the grafted chitosan and chitin. The activation energy ( E a ) and the thermodynamic variables (i.e., standard Gibb&rsquo, s free energy ( &Delta, G 0 ), standard enthalpy ( &Delta, H 0 ), and standard entropy ( &Delta, S 0 )) were determined using the Van&rsquo, t Hoff and Arrhenius equations. The sticking probability ( S *) model for MB and MO removal by chitin and the chitosan derivative demonstrated that both dyes were successfully removed under the proposed conditions. Desorption studies of MB and MO showed the reusability of both materials, suggesting their application for removing dyes from aqueous solution.

WOS: 000469794300001, Hylobius abietis is a plant parasitic insect belonging to the order Coleoptera and which causes severe damages to coniferous forests in Northern and Eastern Europe. This current study is aimed to provide a new viewpoint into the waste of this insect by producing chitosan. Dry insect corpses consisted of 27.9% chitin and 86.2% of the chitin was converted into the chitosan. FT-IR spectra analyses confirmed the purity and the deacetylation degree of the produced chitosan (molecular weight of chitosan; 7.3 kDa). This chitosan exhibited antimicrobial activity against 18 bacterial strains. Further, biodegradable chitosan composite films with beta-carotene were produced. Antioxidant activity of chitosan films were found to be higher than chitosan gels; and beta-carotene incorporation further increased the antioxidative properties of the chitosan films. This study demonstrated that the waste of parasitic insect like H. abietis can be evaluated as a source for production of biodegradable and edible chitosan-based films for applications in food coating.

Articular cartilage degeneration is one of the most common causes of pain and disability in middle-aged and older people. Tissue engineering (TE) has shown great therapeutic promise for this condition. The design of cartilage regeneration constructs must take into account the specific characteristics of the cartilaginous matrix, as well as the avascular nature of cartilage and its cells&rsquo, peculiar arrangement in isogenic groups. Keeping these factors in mind, we have designed a 3D porous scaffold based on genipin-crosslinked chitosan/chitin nanocrystals for spheroid chondral differentiation of human adipose tissue-derived mesenchymal stem cells (hASCs) induced in hypoxic conditions. First, we demonstrated that, under low oxygen conditions, the chondrospheroids obtained express cartilage-specific markers including collagen type II (COL2A1) and aggrecan, lacking expression of osteogenic differentiation marker collagen type I (COL1A2). These results were associated with an increased expression of hypoxia-inducible factor 1&alpha, which positively directs COL2A1 and aggrecan expression. Finally, we determined the most suitable chondrogenic differentiation pattern when hASC spheroids were seeded in the 3D porous scaffold under hypoxia and obtained a chondral extracellular matrix with a high sulphated glycosaminoglycan content, which is characteristic of articular cartilage. These findings highlight the potential use of such templates in cartilage tissue engineering.

[EN] A series of bionanocomposite films based on chitosan, reinforced with chitin nanocrystals, were developed, and assessed in terms of dielectric behaviour and conductivity by using an experimental methodology that allows avoiding the conductivity contribution and the exclusion of contact and interfacial polarization effects. The dielectric relaxations at low and high frequency and temperatures were modeled by Havriliak-Negami functions. Below the glass transition temperature (Tg), the gamma and beta relaxations were observed, which were related to intramolecular and non-cooperative segmental movements. At higher temperatures, an intermolecular and cooperative macromolecular movement, related to the glass transition, gave rise to alpha-relaxation. In addition, two over-Tg p(I) and p(II) relaxations were found, which were related to the displacement of dipoles in the disordered structure of bionanocomposites. The addition of chitin nanocrystals did not affect the apparent activation energy Ea of the gamma-relaxation. However, it decreased the Ea of the beta-relaxation and increased the free volume at temperatures in the vicinities of the alpha-relaxation. Finally, the electric conductivity of the bionanocomposites was lower than that of neat chitosan and chitin due to the interaction between the-OH and-NH2 groups that reduced the ionic mobility, along with the increase of free volume, with the subsequent separation of phases., The European Regional Development Funds and the Spanish Ministry of Science and Innovation for the concession of Research Projects ENE2014-53734-C2-1-R, UPOV13-3E-1947 and ENE2017-86711-C3-1-R are appreciated. Generalitat Valenciana is acknowledged for the project APOSTD14/041 for JD Badia and GRISOLIA/2002/003 for R. Teruel-Juanes. The authors are thankful for the financial support from the Department of Education of the Basque Government (IT1008-18).

International audience; The precise role and value of incorporating nanoforms in biologically active matrices for medical applications is not known. In our current work, we incorporate two chitin nanoforms (i.e., nanocrystals or nanofibers) into Genipin-chitosan crosslinked matrices. These materials were studied as 2D films and 3D porous scaffolds to assess their potential as primary support and guidance for stem cells in tissue engineering and regenerative medicine applications. The incorporation of either nanoforms in these 2D and 3D materials reveals significantly better swelling properties and robust mechanical performance in contrast to nanoform-free chitosan matrices. Furthermore, our data shows that these materials, in particular, incorporation of low concentration chitin nanoforms provide specific topological cues to guide the survival, adhesion, and proliferation of human adipose-derived stem cells. These findings demonstrate the potential of Genipin-chitosan crosslinked matrices impregnated with chitin nanoforms as value added materials for stem cell-based biomedical applications.

Due to its intractable structure and inherent insoluble nature, chitin was for a long time an underutilized resource. The increasing interest in the use of chitin as a source of nanostructured mate ...

Added-value bionanocomposite films were obtained using exclusively oceanic biomass, i.e. chitin nanofillers (nanocrystals- CHNC and nanofibers- CHNF) and chitosan (CS) isolated from Cervimunida johni (yellow lobster) wastes. From these raw materials two sets of bionanocomposite films (CS/CHNC and CS/CHNF) using CS as matrix and CHNC or CHNF as functional agents were prepared by solvent evaporation-casting approach. The bionanocomposite films’ chemistry, structure, mechanical and thermal properties and fungal growth inhibition toward A. niger were analyzed, and the effect of the CHNC and CHNF on the final properties of CS-based bionanocomposite films was evaluated and compared. The data demonstrated that the final properties were dependent of the content and nano nature (size and shape) of chitin nanofillers incorporated in the CS matrix. The CS-based bionanocomposite films reinforced with CHNF showed superior mechanical properties than those prepared with CHNC. Moreover, antifungal assessment demonstrated that CS/CHNF bionanocomposite films presented an inhibitory effect (FGI >80%) against A. Niger . Unquestionably, these bionanocomposite films show a great potential to be used in packaging applications and medical devices.

WOS: 000417661600120, PubMed: 28842199, Natural and synthetic chitin films, obtained from the same source were produced and their physicochemical properties were examined comparatively. Firstly, natural chitin film was obtained from elytra of an insect (Oryctes nasicornis L) and purity of the obtained chitin film (degree of acetylation: 79 +/- 2%) was demonstrated by solid state C-13 nuclear magnetic resonance (C-13 NMR). Then, the synthetic film was produced by dissolving of natural chitin film in LiCl-DMAc. The obtained natural and synthetic films were characterized by AFM, TGA, DSC, FTIR, mechanical properties, light transmission and contact angle. The analyses result demonstrated that natural chitin film lost very important properties such as high thermal stability, transparency, nanofibrous nature, tensile strength, Young's modulus and hydrophobicity after transforming the synthetic film. (C) 2017 Elsevier B.V. All rights reserved.

WOS: 000435056900141, PubMed: 29630959, To overcome the drawbacks of synthetic films in food packaging industry, researchers are turned to natural bio-based edible films enriched with various plant additives. In current study chitosan blend films were produced by incorporating Camelina sativa seed oil at varying concentrations to chitosan matrix. The chitosan blend films were characterized both physicochemically (structural, morphological, thermal, optical and mechanical) and biologically (antimicrobial and antioxidant activity). The incorporation of C sativa seed oil notably enhanced thermal stability, antioxidative, anti-quorum sensing and antimicrobial activity. Except elongation at break, other mechanical properties of the blend films were not affected by incorporation of C sativa seed oil. The surface morphology of blend films was recorded as slightly rough, non-porous and fibre-free surface. As it was expected the optical transmittance in visible region was gradually decreased with increasing fraction of seed oil. Interestingly the hydrophilicity of the blend films revealed a swift increase which can be explained by the formation of micelle between glycerol and Tween 40 in blend films. This study provides valuable information for C sativa seed oil to be used as a blending ingredient in chitosan film technology. (C) 2018 Elsevier B.V. All rights reserved., BAP, Aksaray University [2017-025], Authors are greatly thankful to BAP, Aksaray University for financially supporting the current study under research grant number 2017-025.

WOS: 000429391000054, PubMed: 29329806, Practical application of chitosan-essential oil blend films is limited due to the uneconomical extraction procedure of essential oils from plants. This study aimed to produce chitosan films blended with low cost and commercially available oils and fats consumed in daily human diet (olive, corn and sunflower oils, butter and animal fats). The study also focused on how physicochemical, biological and mechanical properties of chitosan blend films were influenced by the incorporation of oils and fats with varying unsaturation degrees. Possible interactions of chitosan film matrix with incorporated oils or fats were investigated. Chitosan-olive oil film showed better surface morphology and higher thermal stability than the films with other unsaturated oils. Tensile strength, Young's modulus and elongation at break were improved by 57.2%, 25.1% and 31.7% for chitosan-olive oil film, respectively. Chitosan-olive oil blend film had the highest antibacterial activity (almost equal to that of commercial antibiotic gentamicin). Edible films obtained from by incorporation of natural oils and fats into chitosan can help produce an environmentally friendly packaging material that is low cost and easily manufactured. (C) 2018 Elsevier B.V. All rights reserved., Aksaray University [2017-032], This study was funded by Aksaray University (BAP, Code: 2017-032).

WOS: 000410970900021, PubMed: 28927596, The biological material, chitin, is present in nature in three allomorphic forms: alpha, beta and gamma. Whereas most studies have dealt with alpha- and beta-chitin, only few investigations have focused on gamma-chitin, whose structural and physicochemical properties have not been well delineated. In this study, chitin obtained for the first time from the cocoon of the moth (Orgyia dubia) was subjected to extensive physicochemical analyses and examined, in parallel, with alpha-chitin from exoskeleton of a freshwater crab and 5-chitin from cuttlebone of the common cuttlefish. Our results, which are supported by13C CP-MAS NMR, XRD, FT-IR, Raman spectroscopy, TGA, DSC, SEM, AFM, chitinase digestive test and elemental analysis, verify the authenticity of beta-chitin. Further, quantum chemical calculations were conducted on all three allomorphic forms, and, together with our physicochemical analyses, demonstrate that gamma-chitin is distinct, yet closer in structure to alpha-chitin than beta-chitin., DFG [HE 394/3-2]; BHMZ Programme of Dr.-Erich-Kruger-Foundation in Germany, We are thankful for the following financial support - DFG Project HE 394/3-2 and the BHMZ Programme of Dr.-Erich-Kruger-Foundation in Germany.

cited By 20; International audience; Chitin nano-size fillers, i.e. nanocrystals (CHNC) and nanofibers (CHNF), were incorporated in thermoplastic starch matrix via melt-mixing. The two types of thermoplastic starch-based nano-biocomposites (S/CHNC and S/CHNF) were characterized and compared in terms of morphology, chemical and crystal structure, thermal and mechanical properties, and water resistance. In general, all thermoplastic starch-based nano-biocomposites showed better thermal stability, mechanical properties, and storage modulus than thermoplastic starch matrix without chitin nano-size fillers. This can be linked to the good dispersion of the nano-size fillers in the matrix, resulting from their chemical similarity, and also to the strong nano-size fillers-matrix adhesion by hydrogen bonding interactions. The results showed that the final properties of the nano-biocomposites were dependent of the concentration and type of chitin nano-size filler introduced in the thermoplastic starch matrix. In general, the thermoplastic starch-based nano-biocomposites prepared with chitin nanofibers showed better thermal and mechanical properties and storage modulus than those prepared with chitin nanocrystals. © 2014 Elsevier B.V.

WOS: 000412959300106, PubMed: 28684354, Use of plastic based packaging tools is causing both health and economic problems. To overcome this situation, researchers are focusing on the use of different biomaterials such as chitosan and cellulose. The current study was conducted to check the effect of flax (Linum usitatissimum) cellulose nanocrystals (CNC) on mechanical and barrier properties of chitosan-based films. CNC was incorporated in different concentrations (5,10, 20 and 30%). CNC was isolated from flax fiber using acid hydrolysis method. Tensile strength (TS) and young modulus (YM) values increased with the increase of CNC concentration. Chitosan film with 20% CNC revealed the highest YM value as 52.35 MPa. No significant improvement was recorded in water vapor permeability due to overall lower film crystallinity. All the films were observed to be transparent up to an acceptable level. SEM and AFM analysis confirmed the homogeneity of films. A gradual enhancement was recorded in the antimicrobial activity of chitosan/CNC composite films. No significant improvement revealed in the thermal stability of composites. (C) 2017 Elsevier B.V. All rights reserved., Department of Education of the Basque Government, Spain [IT1008-16], This work was financially supported by Department of Education of the Basque Government, Spain [IT1008-16].

The production of fully bio-based and biodegradable nanocomposites has gained attention during recent years due to environmental reasons; however, the production of these nanocomposites on the large-scale is challenging. Polylactic acid/chitin nanocrystal (PLA/ChNC) nanocomposites with triethyl citrate (TEC) at varied concentrations (2.5, 5.0, and 7.5 wt %) were prepared using liquid-assisted extrusion. The goal was to find the minimum amount of the TEC plasticizer needed to enhance the ChNC dispersion. The microscopy study showed that the dispersion and distribution of the ChNC into PLA improved with the increasing TEC content. Hence, the nanocomposite with the highest plasticizer content (7.5 wt %) showed the highest optical transparency and improved thermal and mechanical properties compared with its counterpart without the ChNC. Gel permeation chromatography confirmed that the water and ethanol used during the extrusion did not degrade PLA. Further, Fourier transform infrared spectroscopy showed improved interaction between PLA and ChNC through hydrogen bonding when TEC was added. All results confirmed that the plasticizer plays an important role as a dispersing aid in the processing of PLA/ChNC nanocomposites. The authors gratefully acknowledge Bio4Energy, Kempestiftelserna, and Wallenberg Wood Science Center (WWSC) in Sweden for the financial support of this work. We also thank Deodato Radic at the Pontifical Catholic University of Chile (PUC) for supplying the bleached chitin powder and Dipl.-Ing Daniel Schwendemann at IWK University of Applied Sciences Eastern, Switzerland for kindly providing the polylactic acid. The authors also acknowledge Maxime Noel for the technical support with the FTIR and Ph.D. candidate Shiyu Geng for the HR-SEM images.

As, in the market, poly (lactic acid) (PLA) is the most used polymer as an alternative to conventional plastics, and as functionalized chitin nanocrystals (CHNC) can provide structural and bioactive properties, their combination sounds promising in the preparation of functional nanocomposite films for sustainable packaging. Chitin nanocrystals were successfully modified via acylation using anhydride acetic and dodecanoyl chloride acid to improve their compatibility with the matrix, PLA. The nanocomposite films were prepared by extrusion/compression approach using different concentrations of both sets of functionalized CHNC. This investigation brings forward that both sets of modified CHNC act as functional agents, i.e., they slightly improved the hydrophobic character of the PLA nanocomposite films, and, very importantly, they also enhanced their antifungal activity. Nonetheless, the nanocomposite films prepared with the CHNC modified with dodecanoyl chloride acid presented the best properties. The authors are thankful for the financial support from the European Commission through the European Project ECLIPSE (NMP-280786); the Department of Education of the Basque Government through project IT1008-16; and scholarship of young researchers training and project. The authors also acknowledge the technical and human support of General Research Services (SGIker) from the UPV/EHU for water vapor transmission and oxygen transmission analyses.

WOS: 000393929900026, Sporopollenin-chitosan blend films were produced for the first time. Sporopollenin is a robust structural component of plant pollens exhibiting excellent features such as nontoxicity, biodegradability, biocompatibility, high thermal stability, durability to strong acid and base solutions and homogeneity in size. To benefit from these advantages, sporopollenin samples obtained from Betula pendula (silver birch) were incorporated into chitosan film at different concentration; 10, 20 and 40 mg in 100 mL chitosan gel (1%). Stereo microscopy, FT-IR and TG/DTG analyses showed that sporopollenin was successfully incorporated into the chitosan matrix. Incorporation of sporopollenin in gradually increasing amount into chitosan films was found advantageous in (1) enhancement in chemical durability of the films, (2) increment of hydrophobicity, (3) boosting the mechanical properties, (4) improvement of antifungal and (5) antioxidant activities. This study revealed that sporopollenin can be suggested as an effective blend material for biodegradable edible chitosan film production. (C) 2016 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Cellulose nanofibers and chitin nanocrystals, two main components of agricultural and aquacultural by-products, were obtained from blue agave and yellow squat lobster industrial residues. Cellulose nanofibers were obtained using high pressure homogenization, while chitin nanocrystals were obtained by hydrolysis in acid medium. Cellulose nanofibers and chitin nanocrystals were characterized by X-ray diffraction, Atomic Force Microscopy and Infrared spectroscopy. Self-bonded composite films with different composition were fabricated by hot pressing and their properties were evaluated. Antifungal activity of chitin nanocrystals was studied using a Cellometer(®) cell count device, mechanical properties at tension were measured with a universal testing machine, water vapor permeability was evaluated with a thermohygrometer and surface tension with sessile drop contact angle method. The addition of chitin nanocrystals reduced slightly the mechanical properties of the composite. Presence of chitin nanocrystals influenced the growth of Aspergillus sp fungus in the surface of the composites as expected.

cited By 23; International audience; Chitin nano-objects become more interesting and attractive material than native chitin because of their usable form, low density, high surface area and promising mechanical properties. This work suggests a straightforward and environmentally friendly method for processing chitin nanofibers using dynamic high pressure homogenization. This technique proved to be a remarkably simple way to get α-chitin into α-chitin nanofibers from yellow lobster wastes with a uniform width (bellow 100 nm) and high aspect ratio; and may contributes to a major breakthrough in chitin applications. Moreover, the resulting α-chitin nanofibers were characterized and compared with native α-chitin in terms of chemical and crystal structure, thermal degradation and antifungal activity. The biological assays highlighted that the nano nature of chitin nanofibers plays an important role in the antifungal activity against Aspergillus niger. © 2014 Elsevier Ltd.

cited By 17; International audience; The purpose of this work was to evaluate and compare the role of different nano-chitin morphologies on the structural and functional properties of thermoplastic starch-based films prepared by casting-evaporation approach. The introduction of chitin nano-objects - nanocrystals (CHNC) and nanofibers (CHNF) in concentrations of 5-20% - in thermoplastic starch-based matrices resulted in the enhancement of the final properties of the nanocomposite films in a morphological-dependent manner. The obtained data clearly demonstrate that the nanocomposite films elaborated with chitin nano-objects showed superior mechanical, thermal, barrier and antifungal properties as compared to those prepared with unfilled thermoplastic starch films. Furthermore, chitin nano-objects content, shape and size, were found to be an important role to the final properties of the thermoplastic starch nanocomposite films. Our findings highlight the potential use of such chitin nano-objects in thermoplastic starch-based matrices to be applied in functional food coatings and packaging. © 2014 Elsevier Ltd.