Cork extractives exhibit thermo-oxidative protection properties in polypropylene-cork composites and as direct additives for polypropylene

The thermo-oxidative stability of polypropylene (PP) in composites containing 15 wt.% of cork and the performance of selected cork extracts as stabilizing additives for PP was evaluated by Oxidation Induction Time (OIT) and by Oxidation Onset Temperature (OOT). The results showed that cork increases the OIT of PP in the composite and it was identified that the cork extractives fraction is responsible for such behavior. Selected cork extracts with high antioxidant capacity (determined by dpph radical scavenging and oxygen reactive absorbance capacity assays) were compounded by extrusion with PP in 0.5 and 1.5 wt.%. It was found that the ethanol extract is the most effective as thermo-oxidative stabilizer for PP. At the loading level of 1.5%, the OIT increases from 3.8 (neat PP) to 29.7 min at 200 Â°C and from 1.2 (neat PP) to 9.0 min at 220 Â°C. The OOT also increases from 216 Â°C (neat PP) to 247 Â°C. Mechanical tests, performed on PP loaded with the cork extracts, showed that the presence of these extracts has no significant effect on the polymer mechanical performance. The results demonstrate the suitability of cork as a source of thermo-oxidative stabilizing additives for the formulation of polyolefins, and enable the exploitation of new routes of cork valorization.The authors are grateful to Amorim Cork Composites for providing the cork powder raw material. Ivo Aroso and Emanuel Fernandes are grateful for financial support of FCT through grants SFRH/BD/42273/2007 and SFRH/BPD/96197/2013, respectively. Funding was also granted from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no REGPOT-CT2012-316331-POLARIS and from Project "Novel smart and biomimetic materials for innovative regenerative medicine approaches (Ref.: RL1-ABMR-NORTE-01-0124-FEDER-000016)" co-financed by North Portugal Regional Operational Programme (ON.2 - O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF)

Functionalized cork-polymer composites (CPC) by reactive extrusion using suberin and lignin from cork as coupling agents

High density polyethylene (HDPE) and cork powder were compounded in a co-rotating twin-screw extruder to obtain cork-polymer composites (CPC) with improved properties. Benzoyl peroxide (BPO) was used as initiator agent, and suberin or lignin isolated from cork enhanced filler-matrix bonding and promoted mechanical reinforcement with environmental benefits. The novel composites were characterised in terms of dimensional stability, evolution of morphology, thermal and mechanical properties and their performance was compared with that of composites containing polyethylene-grafted maleic anhydride (PE-g-MA) as coupling agent. As expected, composites with coupling agent present higher mechanical properties, lower water uptake and thickness swelling variation. Suberin acts as plasticizer with antioxidant benefits, while lignin works as a coupling agent, improving tensile modulus and maximum strength. Increasing lignin content does not improve the mechanical properties but improves thermal stability.The work was performed within the project of Corticeira Amorim S.G.P.S. on the development of new products based in/with cork. The authors gratefully acknowledge the financial support, through the COMPETE/QREN/EU funding program in the project with acronym NovelComp (QREN FCOMP-01-0202-FEDER-003107). The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) and POPH/FSE for the doctoral Grants to E.M.F. (SFRH/BD/71561/2010) and I.M.A. (SFRH/BD/42273/2007)

Fundamental studies on natural deep eutectic solvents: physico-chemical, thermal and rheological properties

When combined at particular molar fractions, sugars, aminoacids or organic acids a present a high melting point depression, becoming liquids at room temperature. These are called Natural Deep Eutectic Solvents – NADES and are envisaged to play a major role on the chemical engineering processes of the future. Nonetheless, there is a significant lack of knowledge of its fundamental and basic properties, which is hindering their industrial applications. For this reason it is important to extend the knowledge on these systems, boosting their application development [1]. In this work, we have developed and characterized NADES based on choline chloride, organic acids, amino acids and sugars. Their density, thermal behavior, conductivity and polarity were assessed for different compositions. The conductivity was measured from 0 to 40 °C and the temperature effect was well described by the Vogel-Fulcher-Tammann equation. The morphological characterization of the crystallizable materials was done by polarized optical microscopy that provided also evidence of homogeneity/phase separation. Additionally, the rheological and thermodynamic properties of the NADES and the effect of water content were also studied. The results show these systems have Newtonian behavior and present significant viscosity decrease with temperature and water content, due to increase on the molecular mobility. The anhydrous systems present viscosities that range from higher than 1000Pa.s at 20°C to less than 1Pa.s at 70°C. DSC characterization confirms that for water content as high as 1:1:1 molar ratio, the mixture retains its single phase behavior. The results obtained demonstrate that the NADES properties can be finely tunned by careful selection of its constituents. NADES present the necessary properties for use as extraction solvents. They can be prepared from inexpensive raw materials and tailored for the selective extraction of target molecules. The data produced in this work is hereafter importance for the selection of the most promising candidates avoiding a time consuming and expensive trial and error phase providing also data for the development of models able to predict their properties and the mechanisms that allow the formation of the deep eutectic mixtures.Rita Craveiro and Alexandre Paiva are grateful for financial support from Fundação para a Ciência e a Tecnologia (FCT) through the grants PTDC/EQUEPR/12191/2010/ENIGMA and SFRH/BPD/44946/2008. The research leading to these results has received funding from through the projects ENIGMA - PTDC/EQU-EPR/121491/2010, PTDC/QUI-QUI/119210/2010, PTDC/EQUEQU/122106/2010, PEst-C/EQB/LA0006/2013 from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° REGPOT-CT2012-316331-POLARIS and from Project “Novel smart and biomimetic materials for innovative regenerative medicine approaches (Ref.: RL1 - ABMR - NORTE-01-0124-FEDER-000016)” co-financed by North Portugal Regional Operational Programme (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF)

Water and carbon dioxide: green solvents for the extraction of collagen/gelatin from marine sponges

"Publication Date (Web): December 23, 2014"Marine sponges are extremely rich in natural products and are considered a promising biological resource. The major objective of this work is to couple a green extraction process with a natural origin raw material to obtain sponge origin collagen/gelatin for biomedical applications. Marine sponge collagen has unique physicochemical properties, but its application is hindered by the lack of availability due to inefficient extraction methodologies. Traditional extraction methods are time consuming as they involve several operating steps and large amounts of solvents. In this work, we propose a new extraction methodology under mild operating conditions in which water is acidified with carbon dioxide (CO2) to promote the extraction of collagen/gelatin from different marine sponge species. An extraction yield of approximately 50% of collagen/gelatin was achieved. The results of Fourier transformed infrared spectroscopy (FTIR), circular dichroism (CD), and differential scanning calorimetry (DSC) spectra suggest a mixture of collagen/gelatin with high purity, and the analysis of the amino acid composition has shown similarities with collagen from other marine sources. Additionally, in vitro cytotoxicity studies did not demonstrate any toxicity effects for three of the extracts.The authors are grateful for financial support of FCT through Grant EXP/QEQ:EPS/0745/2012, SWIMS (Subcritical Water Isolation of compounds from Marine Sponges). The funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement numbers REGPOT-CT2012-316331-POLARIS and KBBE-2010-266033 (project SPECIAL), as well as from ERDF under the project "Novel smart and biomimetic materials for innovative regenerative medicine approaches" RLI-ABMR-NORTE-01-0124-FEDER-000016), cofinanced by North Portugal Regional Operational Programme (ON.2,O Novo Norte), under the National Strategic Reference Framework (NSRF) are also gratefully ackowledged. The authors are also truly thankfull to Prof. Micha flan (Tel Aviv University, Israel), Dr. Ronald Osinga (Porifarma, The Netherlands), Dr. Antonio Sara and Dr. Martina Milanese (Studio Associato GAIA, Italy), and Dr. Joana Xavier (University of Azores) for the kind offer of marine sponges samples

Surface modification of silica-based marine sponge bioceramics induce hydroxyapatite formation

Marine biomaterials are a new emerging area of research with significant applications. Recently, researchers are dedicating considerable attention to marine-sponge biomaterials for various applications. We have focused on the potential of biosilica from Petrosia ficidormis for novel biomedical/industrial applications. A bioceramic structure from this sponge was obtained after calcination at 750ºC for 6 hours in a furnace. The morphological characteristics of the 3D architecture were evaluated by scanning electron microscopy (SEM) and micro-computed tomography revealing a highly porous and interconnected structure. The skeleton of Petrosia ficidormis is a siliceous matrix composed of SiO2, which does not present inherent bioactivity. Induction of bioactivity was attained by subjecting the bioceramics structure to an alkaline treatment (KOH 2M) and acidic treatment (HCl 2M) for 1 and 3 hours. In vitro bioactivity of the bioceramics structure was evaluated in simulated body fluid (SBF), after 7 and 14 days. Observation of the structures by SEM, coupled with spectroscopic elemental analysis (EDS), has shown that the surface morphology presented a calcium-phosphate CaP coating, similar to hydroxyapatite (HA). The determination of the Ca/P ratio, together with the evaluation of the characteristic peaks of HA by infra-red spectroscopy and X-ray diffraction, have proven the existence of HA. In vitro biological performance of the structures was evaluated using an osteoblast cell line andthe acidic treatment has shown to be the most effective treatment. Cells were seeded on the bioceramics structures and their morphology, viability and growth was evaluated by SEM, MTS assay and DNA quantification, respectively, demonstrating that cells are able to grow and colonize the bioceramic structures.Alexandre Barros is grateful for financial support of FCT through Grant EXP/QEQ-EPS/0745/2012, SWIMS - Subcritical Water Isolation of compounds from Marine Sponges. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under Grant REGPOT-CT2012-316331-POLARIS and under Grant no KBBE-2010-266033 (project SPECIAL). Funding from the project "Novel smart and biomimetic materials for innovative regenerative medicine approaches" RL1-ABMR-NORTE-01-0124-FEDER-000016) cofinanced by North Portugal Regional Operational Programme (ON.2 - O Novo Norte), under the National Strategic Reference Framework (NSRF) is also acknowledged

Production of Poly(vinyl alcohol) (PVA) fibers with encapsulated natural deep eutectic solvent (NADES) using electrospinning

Functionalized electrospun fibers are of great interest for biomedical applications such as in the design of drug delivery systems. Nevertheless, in some cases the molecules of interest have poor solubility in water or have high melting temperatures. These drawbacks can be overcome using deep eutectic solvents. In this work, poly(vinyl alcohol) (PVA), a common biodegradable biopolymer, was used to produce new functionalized fibers with the eutectic mixture choline chloride:citric acid in a molar ratio of (1:1) ChCl:CA (1:1), which was used as a model system. Fibers were produced from an aqueous solution with 7.8% (w/v) and 9.8% (w/v) of 95% hydrolyzed PVA and a 2% (v/v) of ChCl:CA (1:1). Smooth, uniform fibers with an average diameter of 0.4 μm were obtained with a content of 19.8 wt % of ChCl:CA (1:1) encapsulatedFCT/MEC through the project ENIGMA - PTDC/EQU-EPR/121491/2010, and the project PEst-C/ EQB/LA0006/2013. European Union’s Seventh Framework Programme (FP7/2007-2013) under grant agreement n°REGPOT-CT2012-316331-POLARIS, and from the Project “Novel smart andbiomimetic materials for innovative regenerative medicine approaches (Ref.: RL1 - ABMR - NORTE-01-0124-FEDER-000016) ”cofinanced by the North Portugal Regional Operational Programme (ON.2− O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF). This work was also partly funded by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT - Portuguese Foundation for Science and Technology under the project UID/CTM/50025/2013

Design of controlled release systems for THEDES - therapeutic deep eutectic solvents, using supercritical fluid technology

Deep eutectic solvents (DES) can be formed by bioactive compounds or pharmaceutical ingredients. A therapeutic DES (THEDES) based on ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), and menthol was synthesized and its thermal behavior was analyzed by differential scanning calorimetry (DSC). A controlled drug delivery system was developed by impregnating a starch:poly-ϵ-caprolactone polymeric blend (SPCL 30:70) with the menthol:ibuprofen THEDES in different ratios (10 and 20 wt%), after supercritical fluid sintering at 20 MPa and 50 °C. The morphological characterization of SPCL matrices impregnated with THEDES was performed by scanning electron microscopy (SEM) and micro-computed tomography (micro-CT). Drug release studies were carried out in a phosphate buffered saline. The results obtained provide important clues for the development of carriers for the sustainable delivery of bioactive compounds.Projects ENIGMA - PTDC/EQU-EPR/121491/2010, PTDC/QUI-QUI/119210/2010, PTDC/EQU-EQU/122106/2010, PEst-C/EQB/LA0006/2013 from the European Union’s Seventh Framework Programme (FP7/2007-2013) under grant agreement n° REGPOT - CT2012-316331-POLARIS and from Project “Novel smart and biomimetic materials for innovative regenerative medicine approaches (Ref.: RL1 - ABMR - NORTE-01-0124-FEDER-000016)” co-financed by North Portugal Regional Operational Programme (ON.2–O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF)

Improvement on the mechanical properties of cork composites using suberin as coupling agent through a reactive extrusion process

New functionalized composite structures were prepared using low-density polyethylene (LDPE), cork powder and different suberins extracted from cork and birch outer bark as coupling agents to promote interfacial adhesion. The compounding was performed under reactive extrusion and samples processed by compression moulding. The morphology of the functionalized composites showed good adhesion between cork and the polymeric phase. The mechanical results confirm that the addition of suberin acts as coupling agent improving the strength and leads to cork-polymer composite materials with improved strain and lower modulus. When the suberin was added to the composition a slight increase on the composite density occurred. The new cork-polymer composites demonstrated that this technological approach is industrially appealing.QREN FCOMP-01-0202-FEDER-003107 finance support on the project ”NovelComp”.Portuguese Foundation for Science and Technology (FCT).European project FP6 of Wacheup: New concepts for upgrading pulp and cork mill waste streams to value-added chemicals.Corticeira Amorim S.G.P.S. on the development of new products based in/with cork and for the supply of cork materials

Cork extracts reduce UV-mediated DNA fragmentation and cell death

Accepted ManuscriptUV radiation is known to induce the premature aging of human skin and to contribute to the occurrence of different skin cancers. High doses of UVA (able to penetrate through the epidermis into the dermis) and/or UVB radiation (only affecting the epidermis) leads to cellular oxidative damage compromising the recovery of the normal functions of the cells. This cellular damage is mainly driven by the generation of reactive oxygen species (ROS) that alter the redox status of the intracellular milieu, affecting the cellular metabolic activity, leading to DNA damage, apoptosis and, consequently, to a drastic decrease in the number of live cells, compromising the function of the skin. A series of polyphenolic fractions were extracted from the outer bark (cork) of Quercus suber L., and tested for their capacity to reduce the cellular damage promoted by the ROS produced during UV exposure. This was evaluated after exposing L929 fibroblasts to UV radiation in the presence and absence of the cork extracts. In all the cases the extracts at the concentration of 75μg/ml demonstrated the capacity to preserve cell metabolic activity and their typical morphology, as well as, to avoid DNA fragmentation after exposure to UV radiation. We were also able to correlate these findings with the intracellular reduction of ROS species and the presence of higher proportions of castalagin and vescalagin in the extracts. Our data proves that cork is a relevant source of antioxidant compounds able to act in the cellular environment, protecting cells against oxidation, reducing the number of ROS species and limiting the negative impact of UV radiation. These extracts can be further exploited in the preparation of anti-UV formulations for skin protection.The authors are grateful to Amorim Cork Composites for providing the cork powder raw material and for the financing by the COMPETE/QREN/EU funding program through the project with acronym BioActiveCork (QREN FCOMP-01-0202-FEDER-005455). Ivo M. Aroso and Mariana T. Cerqueira acknowledge the financial support of FCT through the grants SFRH/BD/42273/2007 and SFRH/BPD/96611/2013, respectively. Funding was also granted from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. REGPOT-CT2012-316331-POLARIS and from project "Novel smart and biomimetic materials for innovative regenerative medicine approaches (Ref.: RL1-ABMR-NORTE-01-0124-FEDER-000016)" co-financed by North Portugal Regional Operational Programme (ON.2 and "O Novo Norte"), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF) as appropriate

A fibrin coating method of polypropylene meshes enables the adhesion of menstrual blood-derived mesenchymal stromal cells: a new delivery strategy for stem cell-based therapies

Polypropylene (PP) mesh is well-known as a gold standard of all prosthetic materials of choice for the reinforcement of soft tissues in case of hernia, organ prolapse, and urinary incontinence. The adverse effects that follow surgical mesh implantation remain an unmet medical challenge. Herein, it is outlined a new approach to allow viability and adhesion of human menstrual blood-derived mesenchymal stromal cells (MenSCs) on PP surgical meshes. A multilayered fibrin coating, based on fibrinogen and thrombin from a commercial fibrin sealant, was optimized to guarantee a homogeneous and stratified film on PP mesh. MenSCs were seeded on the optimized fibrin-coated meshes and their adhesion, viability, phenotype, gene expression, and immunomodulatory capacity were fully evaluated. This coating guaranteed MenSC viability, adhesion and did not trigger any change in their stemness and inflammatory profile. Additionally, MenSCs seeded on fibrin-coated meshes significantly decreased CD4+ and CD8+ T cell proliferation, compared to in vitro stimulated lymphocytes (p < 0.0001). Hence, the proposed fibrin coating for PP surgical meshes may allow the local administration of stromal cells and the reduction of the exacerbated inflammatory response following mesh implantation surgery. Reproducible and easy to adapt to other cell types, this method undoubtedly requires a multidisciplinary and translational approach to be improved for future clinical uses.This work was supported by: SANTANDER BANK: “Convenio de colaboración empresarial en actividades de interés general” to F.M.; FUNDAÇÃO PARA A CIÊNCIA E A TECNOLOGIA (FCT): post-doctoral contract CEECIND/01026/2018 to J.M.S.; INSTITUTO DE SALUD CARLOS III (ISCIII): a “PFIS” contract (FI19/00041) to M.Á.P., a “Sara Borrell” grant (CD19/00048) to E.L.; a “Miguel Servet I” grant (MS17/00021), co-funded by the European Social Fund (ESF) “Investing in your future”, and projects CP17/00021 and PI18/0911, co-funded by the European Regional Development Fund (ERDF) “A way to make Europe” to J.G.C.; a “CIBERCV” grant (CB16/11/00494), co-funded by the ERDF to F.M.S.-M; JUNTA DE EXTREMADURA, CONSEJERÍA DE ECONOMÍA, CIENCIA Y AGENDA DIGITAL: project IB20184 (co-funded by ERDF) to E.L. and M.P.; grant GR18199, co-funded by the ERDF, to F.M.S.-M.; contracts TA18054 to I.J. and TA18011 to J.J.L. (cofinanced by FEDER)