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In this study, the starches were isolated from three botanical sources (i.e., rice, sweet potato, and lotus seed). The size distributions of starch granules and molecules were determined by asymmetrical flow-field flow fractionation (AF4), and compared with those measured from optical microscopy (OM) and dynamic light scattering (DLS). Furthermore, the starches were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). AF4 coupled online with UV–visible, multiangle light scattering (MALS), and differential refractive index (dRI) detectors (AF4-UV-MALS-dRI) was employed for the investigation of the digestion and retrogradation properties of starches. Meanwhile, the relationships between the size of starch at nano- to microscale and its functional properties (i.e., digestibility, retrogradation, and thermal properties) were studied by Pearson correlation analysis. AF4-UV-MALS-dRI was proved to be a rapid and gentle method for the separation and size characterization of starches at both micro- and nano-molecule levels. Moreover, it was demonstrated that AF4-UV-MALS-dRI is a useful tool for the monitoring of the digestion and retrogradation properties of starches. The results suggested that the sizes of starch granules and molecules were to some extent correlated with their thermal properties and digestibility, but not with retrogradation property.

The antibacterial and antioxidant packaging films were fabricated by incorporating licorice residue extracts (LREs) into oxidized starch (OS) films. The bioactive fraction (BF) was firstly obtained from LREs by using bioassay-guided isolation method. The BF showed potent anti-Gram(+) bacteria effects, especially against methicillin-resistant S. aureus (MRSA) with MIC of 32.5 μg/mL. The present results also indicated that the addition of BF could significantly decrease the moisture content, water vapor permeability, light transmittance of OS films. Notably, the antibacterial and antioxidant activities of OS films significantly enhanced with the concentration of BF increasing. Moreover, the films with the highest concentration of BF showed the lowest tensile strength (4.23 MPa) and the highest elongation at break (63.89%). Meanwhile, the bioactive films could release bioactive compounds such as licochalcone A and licochalcone B into the alcoholic and fatty food simulants. Taken together, the active OS films containing LREs have the potential for application in food packaging films, due to its potential against MRSA and antioxidant activity as well as good physicochemical properties.

The poly(lactic acid) (PLA) composites with the silane coupling agent treated basalt fiber (SBF) and basalt fiber powder (SBFP) were prepared. The crystalline morphology, mechanical properties, and heat resistance of PLA/SBF/SBFP composites were investigated. The results indicated that SBF or SBFP not only acted as heterogeneous nucleating agents for PLA crystallization but also improved the mechanical properties and heat resistance of PLA. Morphological analyses showed that SBFP could play nucleating role to reduce the spherulites size of PLA, and SBF could restrict the mobility of PLA chains and construct interface crystallization for PLA during isothermal crystallization process. The composites with higher SBF loading, the “Transcrystalline-network” built in the composites significantly improved the heat resistance properties of PLA. Due to the synergistic effect of SBF and SBFP, the PLA/SBF/SBFP composites showed high heat deformation temperature (HDT), especially after isothermal crystallization, the HDT increased to 150.5 °C for the PLA/SBF/SBFP 50/10/40 composite, much higher (about 190%) than that of pure PLA (71.7 °C).

Algal polysaccharide activates macrophages to alter physiologic biomarkers to drive the immunomodulatory phenotype, but it lacks specific biomarkers involved in the biochemical underpinning process. Here, we undertook an extensive analysis of the RAW 264.7 macrophages induced by an immunostimulating sulfated polysaccharide from Caulerpa racemosa var. peltata (CRVP-1) employing combined transcriptomic, proteomic, and metabolomic analyses to reveal the molecular details occurring in the CRVP-1-induced immunomodulatory process. The omics profiling of CRVP-1-activated macrophage demonstrated a total of 8844 genes (4354 downregulated and 4490 upregulated), 1243 proteins (620 downregulated and 623 upregulated), and 68 metabolites (52 downregulated and16 upregulated). Further, the co-mapped correlation network of omics combined with Western blot and immunofluorescence staining indicated that the cluster of differentiation 14 (CD14) might assist Toll-like receptor 4 (TLR4) involved in nuclear factor kappa-B (NF-κB) signaling pathway to drive the immunomodulatory phenotype. Together, our results discover novel physiologic biomarkers in the immunomodulatory activities of algal polysaccharides.

Angelica sinensis polysaccharide (ASP) is one of the main active components of Angelica sinensis (AS) that is widely used in traditional Chinese medicine. ASP is water-soluble polysaccharides, and it is mainly composed of glucose (Glc), galactose (Gal), arabinose (Ara), rhamnose (Rha), fucose (Fuc), xylose (Xyl) and galacturonic acid (GalUA). The extraction methods of ASP include hot water extraction and ultrasonic wave extraction, and different extraction methods can affect the yield of ASP. ASP has a variety of pharmacological activities, including hematopoietic activity, promoting immunity, antitumor, anti-inflammatory, antioxidant, anti-aging, anti-virus, liver protection, and so on. As a kind of natural polysaccharide, ASP has potential application as drug carriers. This review provides a comprehensive summary of the latest extraction and purification methods of ASP, the strategies used for monosaccharide compositional analysis plus polysaccharide structural characterization, pharmacological activities and drug carrier applications, and it can provide a basis for further study on ASP.

In the work, the poly(lactic acid) (PLA)/poly (ethylene-butylacrylate-glycidyl methacrylate) (PTW) blends were prepared by melt compounding. PTW as a toughening agent for PLA, the PLA/PTW blends had good compatibility due to the chemical reaction between the epoxy groups of PTW and the end group of PLA during the blending process. With increasing PTW content from 0 to 20%, the impact strength of PLA/PTW blends was enhanced from 4.6 to 54.1 kJ/m2 and the elongation at break was increased from 5.6% to 270%. The scanning electron microscopy (SEM) images of the impact fracture surfaces showed a large amount of cavities and plastic deformation, which caused by the elastomer and the interfacial adhesion enhanced through the interaction of the terminal functional groups. That was the reason that the toughness of PLA was increased. Finally, proteinase K-catalyzed degradation tests shown that the addition of PTW was beneficial to the biodegradation of PLA and reduced environmental pollution.

A novel water-soluble polysaccharide (named CRVP-1) was successfully obtained from Caulerpa racemosa var peltata by hot-water extraction, ethanol precipitation, and column chromatography. The structure of CRVP-1 was characterized by HPGPC, HPAEC-PAD, FT-IR, GC-MS and NMR. The structural analysis indicated that CRVP-1 possessed a sulfate content of 25.8%±0.7% and was a heteropolysaccharide with an average molecular weight of 29.68kDa, and composed of mannose, galactose, glucose, galacturonic acid, and glucuronic acid with rates of 92.1%, 2.9%, 1.8%, 1.7% and 1.2%, respectively, owning a backbone structure of (1→6)-linked α-D-Manp residues with (1→4)-linked α-D-Manp and (1→2)-linked α-D-Manp residues and side chain that was consisted of (1→4)-linked β-D-Galp residues. The immunostimulatory assay revealed that CRVP-1 had significant effects on the proliferation of macrophage, production of NO and secretion of cytokines (TNF-α, IL-1β and IL-6). These findings provide a scientific basis for further utilization of polysaccharides from C. racemosa var peltata.

The proliferative activity of oyster polysaccharides in intestine epithelial cells (IEC-6) alleviated 5-fluorouracil-induced intestinal inflammation. In this study, we aimed to measure the ability of oyster polysaccharides to promote IEC-6 cell migration and antioxidant activity and further describe their cytoprotective effect on H2O2-challenged IEC-6 cells. The C30–60% fraction of polysaccharides (CHP2) showed rapid stimulation of IEC-6 cell migration after wounding. Then, CHP2 was fractionated into four fractions, namely, CHP2-1, CHP2-2, CHP2-3 and CHP2-4. The CHP2-3 fraction possessed high scavenging activities against 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and oxygen radical absorbance capacity (ORAC), in comparison with other fractions. And CHP2-3 was heteropolysaccharide with sulfuric esters, and it was mainly composed of glucose, galactose and arabinose and had an average molecular weight of 41.81 kDa. Pretreatment with CHP2 and CHP2-3 significantly improved the survival rate of H2O2-treated IEC-6 cells, and reduced intracellular reactive oxygen species (ROS) levels. Moreover, CHP2-3 also significantly decreased H2O2-mediated increases in the secretion of interleukin-1β (IL-1β) and interleukin-6 (IL-6), and attenuated nuclear factor-κB (NF-κB) p65 activation. These results indicate that CHP2-3 may play a vital role in reducing oxidative damage in IEC-6 cells via radical scavenging, decreasing proinflammatory factors secretion, inhibiting the NF-κB pathway, and thus, reducing cell apoptosis.

Considering the high biocompatibility of regenerated silk fibroin (RSF) and the good enhancement effect of graphene oxide (GO), various RSF/GO composite materials have been previously investigated, and found that GO plays a vital role in the fabrication of high-performance RSF/GO materials. However, its effects on the structure of RSF solution are unclear. Therefore, in this work, we studied the rheological and optical properties, as well as the aggregation behavior of concentrated RSF/GO solution in response to applied shear. The results demonstrated that the presence of GO sheets in RSF solution increased the shear resistance, while delayed the sol-gel transition. Moreover, GO sheets were not favorable to the formation of the ordered structures of RSF. The results from small angle X-ray scattering (SAXS) of RSF/GO solution also showed that the shear process promoted the formation of RSF/GO interface. The data also provided insights into the structural evolution within the mixture solutions, which can be beneficial to the future design and fabrication of nanofiller-reinforced high-performance materials.

Porphyran sulfated galactan extracted from red algae Porphyra haitanensis is a sulfated polysaccharide, which possesses excellent activities. In the present study, WI-38 cells were treated with H2O2 to induce premature senescence and then the protection of porphyran against aging in vitro and associated molecular mechanisms were investigated. The protection occurred in a dose-dependent manner, offering an optimal efficacy starting at 10μg/mL. The proportion of SA-β-gal positive cells in porphyran group decreases from 53% to 23% in the cultures at 30 PDs. Porphyran has been detected specifically reducing SAHF-like foci formation in senescent cells. In addition, porphyran significantly affected the p53-p21 pathways in H2O2-treated WI-38 cells. Our data suggest the promising role of porphyran as an attractive and bio-safe agent with the potential to retard senescence and attenuate senescence-related diseases.

A comparative study on interfacial crystallization of poly( l -lactic acid) (PLLA) with different stereoregularity (PLLA2003D 96.0%, PLLA4032D 98.5%, and PLLA290 99.2%) surrounding macroscopic basalt fibers (BF) has been carried out in polymer composites. The effect of stereoregularity on the interface crystallization was systemically studied by microstructure. From polarized optical microscopy (POM) analysis, it was found that the transcrystallinity of PLLA was influenced by temperature. Moreover, stereoregularity significantly affects the crystallization kinetics. It was also found that increased molecular mobility providing faster orientation with high stereoregularity and low molecular weight. It might be the reason for the observation that the PLLA290 samples crystallized more rapidly than the PLLA4032D samples. Appropriate molecular stereoregularity exhibits a clear increase in extensional stress that is directly correlated with the crystalline orientation of the crystallization samples. The mechanism of formation of transcrystallinity underwent the process of “a mismatch in thermal expansion coefficients” with the extensional stress.

A novel polysaccharide (PFP1) with an average molecular weight of 2.02 × 105 g/mol was isolated from Passiflora foetida fruits through hot water extraction, ethanol precipitation and column chromatography. The structure of PFP1 was determined by GPC-MALS-RI, IC, FT-IR, GC–MS and NMR. The structural analysis showed that PFP1 was a heteropolysaccharide and composed of mannose (48.83%), galactose (32.46%), glucose (6.21%), arabinose (5.88%), fructose (2.24%), galacturonic acid (2.20%), xylose (1.17%), fucose (0.17%), ribose (0.05%), and glucuronic acid (0.78%), with a backbone structure of →1)-α-D-Manp→1,2)-β-D-Manp-linked 1,2,6)-β-D-Manp residues and side chains consisted of →1)-β-D-Galp, →1,4)-α-D-Manp, →1, 4)-β-D-Glcp, →1,3)-α-D-Galp, →1,6)-β-D-Manp, →1,6)-β-D-Galp, →1,2,3)-β-D-Manp and →1,3,6)-β-D-Galp residues. The results of immune-enhancing assays revealed that PFP1 could obviously promote the production of NO and secretion of cytokines (TNF-α and IL-6) of macrophage RAW264.7. These findings demonstrate that P. foetida fruit polysaccharides can be utilized as a potential immune-enhancing functional food.

The proliferative activity of oyster polysaccharides in intestine epithelial cells (IEC-6) alleviated 5-fluorouracil-induced intestinal inflammation. In this study, we aimed to measure the ability of oyster polysaccharides to promote IEC-6 cell migration and antioxidant activity and further describe their cytoprotective effect on H

Porphyran sulfated galactan extracted from red algae Porphyra haitanensis is a sulfated polysaccharide, which possesses excellent activities. In the present study, WI-38 cells were treated with H

Microfluidic chips with single channel were built to mimic the shear and elongation conditions in the spinning apparatus of spider and silkworm. Silk fibers dry-spun from regenerated silk fibroin (RSF) aqueous solution using the chip could be tougher than degummed natural silk. The artificial silk exhibited a breaking strength up to 614 MPa, a breaking elongation up to 27% and a breaking energy of 101 kJ/kg.

In this paper, a simple and effective method was applied to enhance regenerated silk fibroin (RSF) mats electrospun from aqueous solution. The mats were first mechanically drawn in 90 vol.% ethanol aqueous solution and then immersed in the same solution for 30 min. The morphology, structure, thermal and mechanical properties of the RSF mats with different draw rates and draw ratios were investigated by scanning electron microscope (SEM), Raman spectroscopy, wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and tensile test. Results revealed that the content of β-sheet conformation, the crystallinity and the number of fibers aligned to the drawing direction increased evidently with the draw ratio. The breaking strength and breaking energy of the post-treated mats at 1.4× draw ratio and 0.1mm/s draw rate were 8.6 MPa and 172.2 J/kg, respectively. However, those of the as-spun mats were only 1.8 MPa and 93.2 J/kg, respectively. The enhanced RSF mats prepared from entirely aqueous solutions may have extensive applications for tissue engineering.

The coaxial electrospinning using the regenerated silk fibroin (SF) and silk sericin (SS) aqueous solutions as the core and shell spinning dopes, respectively, was carried out to prepare regenerated SF/SS composite fibers with components and core-shell structure similar to the natural silkworm silks. It was found from the scanning electron microscope (SEM) and transmission electron microscope (TEM) results that the core dope (SF aqueous solution) flow rate (Q(c)) and the applied voltage (V) had some effects on the morphology of the composite fiber. With an increase in Q(c), the diameter nonuniformity and eccentricity of the core fiber became serious, while the increasing V played an inverse role. In this work, the suitable Q(c) for the fiber formation with better electrospinnability was about 6 μL/min, and the corresponding optimum V was 40 kV. Moreover, the results from Raman spectra analysis, modulated differential scanning calorimetry (MDSC), thermogravimetry (TG) measurement and mechanical property test showed that, compared with the pure SF fiber, the coaxially electrospun SF/SS fiber had more β-sheet conformation, better thermostability and mechanical properties. This was probably because that SS played significant roles in dehydrating SF molecules and inducing the conformational transition of SF to β-sheet structure.

The preparation and characterization of nitric oxide (NO)-releasing chitosan-folate conjugates were reported. The secondary amine chitosan-folate conjugates exhibited a high storage capacity for NO (up to 84.3 nmol NO/mg) (when the graft rate of folate was 12.5%), greatly increasing the "payload" of released NO with the graft rate of folate increasing. The NO release durations (12h) observed for secondary amine the chitosan-folate conjugates with the high graft rate (12.5%) were largerly shorter compared to O2-protected diazeniumliolates with BrCH2CH3 (24 h), thus illustrating a macromolecular effect on NO release kinetics.