15 research outputs found

    Spheronized drug microcarrier system from canola straw lignin

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    Inhomogeneous lignin from canola (rapeseed) straw was isolated and valorized as regularly shaped spherical microparticles for drug delivery formulations. Lignin with a purity of 83% and broad molecular weight distribution (Ɛ > 5.0) was extracted by alkali pulping and acetylated to increase spheronization ability. Lignins with high degrees of acetylation (0.76 and 0.89) were successfully assembled into microparticles with uniform sizes (approximately 2 Ī¼m) and smooth spherical surfaces via solvent-antisolvent precipitation. Hydrophobic coumarin 153 and positively charged ciprofloxacin were used as model drugs to assess the encapsulation and release performance of the lignin microparticles. Highly acetylated lignin microparticles displayed encapsulation efficiencies of 89.6% for coumarin 153 and 90.6% for ciprofloxacin. SEM images showed that coumarin 153 was encapsulated in the hydrophobic core, while ciprofloxacin was adsorbed on the less hydrophobic shell. The synthesis of lignin microcarriers not only provides a facile approach to utilizing waste canola straw lignin for drug delivery matrices but also has the potential to serve as an alternative lignin powder feedstock for bio-based materials.</p

    Green Semi-IPN Hydrogels by Direct Utilization of Crude Wood Hydrolysates

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    Crude and unmodified acetylated galactoglucomannan containing wood hydrolysate (WH) was directly incorporated into a semi-interpenetrating network (semi-IPN) composed of up to 60% renewable polymers. Semi-IPNs were produced by a facile and green synthetic pathway through cross-linking modified carboxymethylcellulose in the presence of at least 30%(w/w) WH, via free radical copolymerization with acrylic acid and <i>N</i>,<i>N</i>ā€²-methylenebisĀ­(acrylamide). FTIR verified the presence of WH interlaced with CMC in the semi-IPN, and the highly porous microscopic structure of the networks was confirmed by SEM. The gelation process of these networks was monitored in situ, and their individual ā€œgel pointā€ (the <i>G</i>ā€²-<i>G</i>ā€³ crossover) was determined by in situ rheological measurements. Semi-IPN hydrogels with various swelling ratios (<i>Q</i> = 20ā€“225) were obtained within 2.8ā€“20 min of a cross-linking reaction

    Thiolated Hemicellulose As a Versatile Platform for One-Pot Click-Type Hydrogel Synthesis

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    A one-pot synthetic methodology for the thiolation of <i>O</i>-acetyl-galactoglucomannan (AcGGM) was developed to merge hemicellulose chemistry with ā€œclickā€ chemistry. This was realized by the AcGGM-mediated nucleophilic ring-opening of Ī³-thiobutyrolactone via the activation of the polysaccharide pendant hydroxyl groups. The incorporation of thiol functionalities onto the hemicellulose backbone was visualized by <sup>1</sup>H and <sup>13</sup>C NMR spectroscopy and was assessed by an Ellmanā€™s reagent assay of the thiol groups. The versatility of the thiolated AcGGM was elaborated and demonstrated by conducting several postmodification reactions together with hydrogel formation utilizing thiolā€“ene and thiol-Michael addition ā€œclickā€ reactions. The one-pot synthesis of thiolated AcGGM is a straightforward approach that can expand the applications of hemicelluloses derived from biomass by employing ā€œclickā€ chemistry

    Innovative Approaches for Converting a Wood Hydrolysate to High-Quality Barrier Coatings

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    An advanced approach for the efficient and controllable production of softwood hydrolysate-based coatings with excellent oxygen-barrier performance is presented. An innovative conversion of the spray-drying technique into a coating applicator process allowed for a fast and efficient coating process requiring solely aqueous solutions of softwood hydrolysate, even without additives. Compared to analogous coatings prepared by manual application, the spray-drying produced coatings were more homogeneous and smooth, and they adhered more strongly to the substrate. The addition of glyoxal to the aqueous softwood hydrolysate solutions prior to coating formation allowed for hemicellulose cross-linking, which improved both the mechanical integrity and the oxygen-barrier performance of the coatings. A real-time scanning electron microscopy imaging assessment of the tensile deformation of the coatings allowed for a deeper understanding of the ability of the coating layer itself to withstand stress as well as the coating-to-substrate adhesion

    Innovative Approaches for Converting a Wood Hydrolysate to High-Quality Barrier Coatings

    No full text
    An advanced approach for the efficient and controllable production of softwood hydrolysate-based coatings with excellent oxygen-barrier performance is presented. An innovative conversion of the spray-drying technique into a coating applicator process allowed for a fast and efficient coating process requiring solely aqueous solutions of softwood hydrolysate, even without additives. Compared to analogous coatings prepared by manual application, the spray-drying produced coatings were more homogeneous and smooth, and they adhered more strongly to the substrate. The addition of glyoxal to the aqueous softwood hydrolysate solutions prior to coating formation allowed for hemicellulose cross-linking, which improved both the mechanical integrity and the oxygen-barrier performance of the coatings. A real-time scanning electron microscopy imaging assessment of the tensile deformation of the coatings allowed for a deeper understanding of the ability of the coating layer itself to withstand stress as well as the coating-to-substrate adhesion

    A Strategy for the Sequential Recovery of Biomacromolecules from Red Macroalgae Porphyra umbilicalis KuĢˆtzing

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    A nondestructive, multicomponent fractionation strategy has been developed to extract proteins and polysaccharides from the red macroalgae Porphyra umbilicalis collected along the west coast of Sweden and cultivated indoors under controlled conditions. First, a protein-rich fraction was extracted in an ice-cold alkaline solution. The overall protein content in Porphyra umbilicalis was estimated to be 30.6% of the dry weight, and out of that, 15.0% could be recovered. Water-soluble polysaccharides were then extracted from the insoluble residual fraction using sequential alkaline and acidic treatments at 90 Ā°C for 4 h. Spectroscopic and chromatographic analyses of the polysaccharide fractions show that high-molecular-weight carrageenans were obtained from the alkaline extraction and a galactose-rich pectin substance was obtained from the acidic extraction. The insoluble fraction remaining after all extraction steps was rich in cellulose. An elemental analysis of Porphyra umbilicalis via scanning electron microscopy with energy-dispersive X-ray spectrometry (SEM-EDS) showed the presence of C, O, Na, Ca, Mg, Al, Cl, and S. However, no heavy metals or other toxic elements, such as Pb, Hg, and As, were found

    In Situ Synthesis of Magnetic Field-Responsive Hemicellulose Hydrogels for Drug Delivery

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    A one-pot synthetic methodology for fabricating stimuli-responsive hemicellulose-based hydrogels was developed that consists of the in situ formation of magnetic iron oxide (Fe<sub>3</sub>O<sub>4</sub>) nanoparticles during the covalent cross-linking of O-acetyl-galactoglucomannan (AcGGM). The Fe<sub>3</sub>O<sub>4</sub> nanoparticle content controlled the thermal stability, macrostructure, swelling behavior, and magnetization of the hybrid hydrogels. In addition, the magnetic field-responsive hemicellulose hydrogels (MFRHHs) exhibited excellent adsorption and controlled release profiles with bovine serum albumin (BSA) as the model drug. Therefore, the MFRHHs have great potential to be utilized in the biomedical field for tissue engineering applications, controlled drug delivery, and magnetically assisted bioseparation. Magnetic field-responsive hemicellulose hydrogels, prepared using a straightforward one-step process, expand the applications of biomass-derived polysaccharides by combining the renewability of hemicellulose and the magnetism of Fe<sub>3</sub>O<sub>4</sub> nanoparticles

    Facile and Green Approach towards Electrically Conductive Hemicellulose Hydrogels with Tunable Conductivity and Swelling Behavior

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    A one-pot reaction to synthesize electrically conductive hemicellulose hydrogels (ECHHs) is developed via a facile and green approach in water and at ambient temperature. ECHHs were achieved by cross-linking <i>O</i>-acetyl-galactoglucomannan (AcGGM) with epichlorohydrin in the presence of conductive aniline pentamer (AP) and were confirmed by infrared spectroscopy (IR) and elemental analysis. All hydrogels had macro-porous structures, and the thermal stability of ECHHs was improved by the addition of AP. Hydrogel equilibrium swelling ratios (ESRs) varied from 13.7 to 11.4 and were regulated by cross-linker concentration. The ESRs can also be tuned from 9.6 to 6.0 by changing the AP content level from 10 to 40% (w/w) while simultaneously altering conductivity from 9.05 Ɨ 10<sup>ā€“9</sup> to 1.58 Ɨ 10<sup>ā€“6</sup> S/cm. ECHHs with controllable conductivity, tunable swelling behavior, and acceptable mechanical properties have great potential for biomedical applications, such as biosensors, electronic devices, and tissue engineering

    Prehydrolysis in Softwood Pulping Produces a Valuable Biorefinery Fraction for Material Utilization

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    A scaled-up prehydrolysis process was elaborated to demonstrate an industrially feasible operation step in a pulping process that generates a valuable side product in addition to the cellulose pulp. The valuable side product is aqueous process liquor, a softwood hydrolysate (SWH) herein produced in 60 L batches, and its components were recovered and utilized as materials. The process parameters were shown to influence the yield, composition, and quality of the obtained hydrolysates. Furthermore, the process conditions were shown to influence the ability of SWHs to form free-standing, foldable films in blends with either microfibrillated cellulose (MFC) or carboxymethyl cellulose (CMC). Films with oxygen permeabilities (OP) as low as 0.35 cm<sup>3</sup> Ī¼m day<sup>ā€“1</sup> m<sup>ā€“2</sup> kPa<sup>ā€“1</sup> at 50% relative humidity, were produced from aqueous solutions providing a viable and green alternative to petroleum-based packaging barriers. The OPs were very low regardless of SWH film composition and upgrading conditions, whereas the filmsā€™ tensile performance was directly controlled by the ratio of SWH to cocomponent
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