Pearcebroch8523

The present review focus on the potential of chitosan-based membranes to be employed in the separation of terpenes by pervaporation; the pervaporation is also addressed as an emerging process for the separation of essential oil components. Essential oils and their components are important feedstocks for several branches of industry, also having potential to be used in active packaging and to combat agricultural pests. Industrially, the fractionation of essential oils is carried out by fractional distillation under vacuum, a method that is economically and energetically costly. Several kinds of chitosan-based membranes for pervaporation separations are also presented. Additionally, it is presented a brief discussion about the challenges of using this kind of material, and conventional polymers, to separate organic compounds by pervaporation. Although most of chitosan-based pervaporation membranes are aimed to hydrophilic pervaporation, there are works which employed this biopolymer in target-organophilic pervaporation, with successful results. Along with the well-established use of pervaporation in the food industry, mainly in the obtainment of aroma compounds, the development and application of chitosan-based membranes may help to overcome the current difficulties of the target-organophilic pervaporation, especially regarding the separation of essential oils and essential oil components.Effects of repeated annealing treatments (8 cycles, 12 h each) or continuous annealing treatments (12-96 h) at 50 °C on structural, physicochemical, and digestive properties of normal and waxy wheat starches were investigated. Wheat starches retained the original crystalline structure of A-type after annealing. Annealing treatments increased crystallinity, short chain of amylopectin, viscosity, and gelatinization temperatures of starch. However, molecular weight, long chain of amylopectin, solubility, and swelling power of starch decreased after annealing. Additionally, annealing reduced the in vitro digestibility of wheat starches. The changes in properties of starch varied depending on starch type, normal or waxy, and annealing methods, repeated or continuous. The repeated annealing was found to be more effective in modification of normal wheat starch properties. However, continuous annealing efficiently modified properties of the waxy wheat starch. The obtained results may help in choosing appropriate applications of annealed wheat starches in the food industry.Starch granule-associated proteins (SGAPs) include granule-surface proteins (SGSPs) and granule-channel proteins (SGCPs). To investigate impacts of SGAPs on amyloglucosidase (AMG) hydrolysis, waxy and non-waxy rice starches had their SGCPs or SGAPs removed. Removal of SGAPs or SGCPs did not affect morphology and amylopectin chain distribution but decreased relative crystallinity. Removal of SGAPs increased the digestion rate, AMG binding ability and pore diameter of hydrolyzed granules, and accelerated changes in relative crystallinity and destruction of crystalline region on hydrolysis. However, after removing SGCPs, AMG only bound to surface and attacked of the fingerprint of protein bodies on granules, with decreased hydrolysis rate. The degree of change in hydrolysis rate was not determined by SGCPs content of rice starch. These results implied that SGCPs had a more dominant role in AMG hydrolysis of rice starch than did SGSPs. This study provides novel information about the role of SGAPs in AMG hydrolysis mechanisms.Microencapsulation of polysaccharidic nanoparticles is met with nanoscale and biological performance changes. This study designs soft agglomerates as nanoparticle vehicle without nanoparticles undergoing physical processes that alter their geometry. The nanoparticles were made of high molecular weight chitosan/pectin with covalent 5-fluorouracil/folate. Nanoparticle aggregation vehicle was prepared from low molecular weight chitosan. The nanoparticles and aggregation vehicle were blended in specific weight ratios to produce soft agglomerates. Nanoparticles alone are unable to agglomerate. Adding aggregation vehicle ( less then 2 μm) promoted soft agglomeration with nanoparticles deposited onto its surfaces with minimal binary coalescence. selleck chemicals The large and rough-surfaced aggregation vehicle promoted nanoparticles deposition and agglomeration. A rounder vehicle allowed assembly of nanoparticles-on-aggregation vehicle into agglomerates through interspersing smaller between larger populations. Soft agglomeration reduced early drug release, and was responsive to intracapsular sodium alginate coat to further sustain drug release. The soft agglomerates can serve as a primary oral colon-specific vehicle.Nanocomposites as "stevedores" for co-delivery of multidrugs hold great promise in addressing the drawbacks of traditional cancer chemotherapy. In this work, our strategy presents a new avenue for the stepwise release of two co-delivered agents into the tumor cells. The hybrid nanocomposite consists of a pH-responsive chitosan (CS), a thermosensitive poly(N-vinylcaprolactam) (PNVCL) and a functionalized cell-penetrating peptide (H6R6). Doxorubicin (DOX) and oleanolic acid (OA) are loaded into the nanocomposite (H6R6-CS-g-PNVCL). The system displayed a suitable size (∼190 nm), a high DOX loading (13.2 %) and OA loading efficiency (7.3 %). The tumor microenvironment triggered the nanocomposite to be selectively retained in tumor cells, then releasing the drugs. Both in vitro and in vivo studies showed a significant enhancement in antitumor activity of the co-delivered system in comparison to mono-delivery. This approach which relies on redox, pH and temperature effects utilizing co-delivery nanosystems may be beneficial for future applications in cancer chemotherapy.Heparin was immobilized on magnetic chitosan particles to be used as a tool for human plasma protein identification. Chitosan was magnetized by co-precipitation with Fe2+/Fe3+ (MAG-CH). Heparin was functionalized with carbodiimide and N-hydroxysuccinimide and covalently linked to MAG-CH (MAG-CH-hep). X-ray diffraction confirmed the presence of chitosan and Fe3O4 in MAG-CH. This particle exhibited superparamagnetism and size between 100-300 μm. Human plasma diluted with 10 mM phosphate buffer (pH 5.5) or 50 mM Tris-HCl buffer (pH 8.5) was incubated with MAG-CH-hep, and the proteins fixed were eluted with the same buffers containing increasing concentrations of NaCl. The proteins obtained were investigated by SDS-PAGE, LC/MS, and biological activity tests (PT, aPTT, and enzymatic chromogenic assay). Inhibitors of the serpin family, prothrombin, and human albumin were identified in this study. Therefore, MAG-CH-hep can be used to purify these proteins and presents the following advantages low-cost synthesis, magnetic separation, ion-exchange purification, and reusability.