15 research outputs found
Spheronized drug microcarrier system from canola straw lignin
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 (Ć > 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
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>ā²-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 āgel pointā (the <i>G</i>ā²-<i>G</i>ā³ crossover) was determined by
in situ rheological measurements. Semi-IPN hydrogels with various
swelling ratios (<i>Q</i> = 20ā225) were obtained
within 2.8ā20 min of a cross-linking reaction
Thiolated Hemicellulose As a Versatile Platform for One-Pot Click-Type Hydrogel Synthesis
A one-pot synthetic methodology for
the thiolation of <i>O</i>-acetyl-galactoglucomannan (AcGGM)
was developed to merge hemicellulose
chemistry with āclickā 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 Ellmanās 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 thiolāene and thiol-Michael
addition āclickā reactions. The one-pot synthesis of
thiolated AcGGM is a straightforward approach that can expand the
applications of hemicelluloses derived from biomass by employing āclickā
chemistry
Innovative Approaches for Converting a Wood Hydrolysate to High-Quality Barrier Coatings
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
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 KuĢtzing
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
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
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 Ć 10<sup>ā9</sup> to 1.58 Ć
10<sup>ā6</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
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>ā1</sup> m<sup>ā2</sup> kPa<sup>ā1</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