Biopolymers as films are defined as materials prepared from biological molecules with filmogenic morphology that can be versatile uses. The present research aimed to study formulations of natural polymeric composites based on babassu coconut mesocarp (BCM), alginate and glycerol, to verify the effect of these components on moisture, solubility, thickness and water vapor permeability (WVP) parameters for different cross-linking stages. After a second cross-linking was applied, they presented lower thickness, solubility, and WVP values than first cross-linking. Consecutive analyses for selected film formulations showed that the formulation to solutions of 400 mL with 3g of BCM, 7.5g of alginate and 4.0g of glycerol had the most promising results when correlating physical parameters with thermal analyses, chemical and mechanical properties. Films with amount of babassu coconut mesocarp in the proportion established were sturdy to solubility, leaching and thermal degradation, improved by second cross-linking applied.

In this study, three endoglucanases (EGs; Cel7B, Cel5B, and Cel12A), one cellobiohydrolase (CBH), and two auxiliary proteins (swollenin: SWO1 and SWO4) were used to hydrolyze microcrystalline cellulose (MCC) for cellulose nanocrystal (CNC) preparation. The mixture experiment of the three EGs showed that high CNC yield was obtained when the ratio of Cel7B and Cel5B is 1:1.11 (protein weight). Moreover, the addition of CBH (1 mg/g) and SWO1 from Trichoderma reesei effectively increased the yield of CNC. On the basis of the results, the cellulase-producing strain of Penicillium oxalicum M12 was engineered to improve its cellulase system. An engineered strain of cEES performed well in CNC preparation. CNC with a yield of 11.79% and a crystallinity of 83.85% were produced using the crude enzyme from cEES as a means to hydrolyze MCC, and the size and shape of CNC were uniform and fusiform.

Fibrillar gel of pepsin-solubilized collagen from tilapia skin was prepared by self-assembly in neutral phosphate buffer at 28 °C. Then effects of acidic polysaccharides, such as sodium alginate (SA), chondroitin sulfate (CS), and hyaluronic acid (HA), on the formation and properties of self-assembled fibrillar gel were investigated. SA and CS prolonged gelling time, whereas HA had no obvious effect. SA made fibril network denser, while CS and HA induced the presence of larger ordered structures. All the acidic polysaccharides broadened the D-periodicity of fibrils. SA and HA increased the maximum mechanical strength of gel to 39.64 and 34.49 kN/m2, respectively, significantly higher than that of pure collagen gel (14.53 kN/m2), while that only 17.20 kN/m2 after CS introduced. HA had no evident effect on enzymatic resistance, while SA and CS decreased. Therefore, tilapia skin collagen with HA has a higher potential as a biomaterial than that with CS or SA.

In this research, cellulose nanocrystal (CNC) was synthesized from cotton waste using controlled hydrolysis against 64% (w/w) sulfuric acid solution. The produced nanoparticles were then characterized using FTIR, XRD, TGA, and DLS analyses. Biaxial electrospinning technique was used to produce CNC incorporated PCL-PVA/NaAlg nanofibers. The sodium alginate portion was then crosslinked via submerging the samples in calcium chloride aqueous solution. The CNC incorporated and crosslinked sample was characterized using SEM, FTIR, and TGA techniques. Results confirmed the presence of CNC nanoparticles and alginate crosslinking reaction. Mechanical studies showed that CNC incorporation increases the tensile modulus by 65%. Also, the crosslinked samples exhibited an increase in elongation at break. Water contact angle studies suggested that CNC incorporation and crosslinking improves nanofiber hydrophilicity. Cell viability of more than 90% was observed in CNC incorporated PCL-CaAlg nanofibers. Also, SEM images of cells on nanofiber scaffolds showed better cell growth and attachment in PCL-CaAlg-CNC samples.

Cellulose nanocrystals (CNCs) per their twisting structure and high aspect ratio and charged surface property are increasingly receiving great attention in chiral photonic crystal and pigment fabrication. However, the cholesteric mesophases of CNCs is unstable and easily destroyed by the additives with high Mw. In this work, hydroxypropyl cellulose (HPC) and carboxymethyl cellulose (CMC) are incorporated into CNCs for a continuous mesophase transition monitoring. We investigated the effects of HPC and CMC on the properties of CNCs with respect to the morphology, mesophase, rheology, and structure-color properties. Our results showed that the addition of CMC (≥ 1 wt%) prevented the formation of a continuous cholesteric phase but resulting in a fast gelation due to the strong repulsion between CMC and CNCs. Alternatively, the cholesteric phase was well-preserved in the CNC/HPC in which HPC (< 10 wt%) served as an efficient tuner of phase transition, color hue and rheology properties.

Antibacterial dressing can prevent the occurrence of many infections of wounds. Bacterial cellulose (BC) has the ability to carry and transfer the medicine to achieve a wound healing bandage. In this study, Carbon Quantum Dots-Titanium dioxide (CQD-TiO2) nanoparticles (NP) were added to BC as antibacterial agents. FTIR Spectroscopy illuminated that NPs were well-bonded to BC. Interestingly, MIC test proved that BC/CQD-TiO2 nanostructure (NS) has anti-bacterial properties against Staphylococcus aureus. The findings indicated that, CQD-TiO2 NPs have stronger antibacterial properties with better tensile strength compared to CQD NPs, in a concentration-dependent manner. Toxicity of CQD-TiO2 NPs on human L929 fibroblast cells was also evaluated. Most importantly, the results of the scratch test indicated that the NS was effective in wound healing in L929 cells. The approach in this study may provide an alternative to make an antibacterial wound dressing to achieve an effective drug-based bandage.

Wound healing can lead to complex clinical problems, hence finding an efficient approach to enhance the healing process is necessary. An ideal wound dressing should treat wounds at reasonable costs, with minimal inconveniences for the patient. Chitosan is one of the most investigated biopolymers for wound healing applications due to its biocompatibility, biodegradability, non-toxicity, and antimicrobial activity. Moreover, chitosan and its derivative have attracted numerous attentions because of the accelerating wound healing, and easy processability into different forms (gels, foams, membranes, and beads). All these properties make chitosan-based materials particularly versatile and promising for wound dressings. Besides, secondary natural metabolites could potentially act like the antimicrobial and anti-inflammatory agents and accelerate the healing process. This review collected almost all studies regarding natural compounds applications in wound healing by focusing on the chitosan-based bioactive wound dressing systems. An accurate analysis of different chitosan formulations and the influence of bioactive compounds on their wound healing properties are reported.

In this work, we present a solid silicon substrate functionalized with modified β-cyclodextrin monolayers as an optimal surface for organic contaminant uptake. The inclusion and capture of three potential pollutants, 4-chlorophenoxyacetic acid, 4-aminobenzoic acid and phenylethylamine, were studied. 1H-NMR and ROESY studies revealed the complete inclusion and details of the conformational orientation of the three guests in the per-(6-amino-6-deoxy)-β-cyclodextrin matrix, forming three new inclusion complexes that have not yet been reported. Capture assays for the guests were carried out by immersing the substrates in an aqueous pollutant solution and by measuring the UV-vis spectra. This substrate showed a high sorption capacity at equilibrium, between 2.5 × 10-5 and 6.0 × 10-5 mmol/substrate, for the studied pollutants. In addition, this surface can be reused four times with an efficiency equal to the initial use. Therefore, it could be a versatile platform that could be applied for the capture of other organic pollutants from water.

Naked-eye detection pH sensor is becoming a powerful tool in food safety monitoring. In this work, a pH sensor was developed by incorporating cellulose modified with acidochromic dye into polyvinyl alcohol (PVA). The results indicated that the dye (up to 170.4 μmol/g) was successfully anchored to cellulose. It was demonstrated that the addition of acidochromic regenerated cellulose (ARC) resulted in enhancement of tensile strength, elongation at break and maximum decomposition temperature by 44%, 43.6% and 11 °C, respectively. The pH sensor demonstrated that a visible color change from yellow to brick-red and to purple when placed in solutions of pH = 7, 10 and 12. The pH sensor showed excellent resistance to leaching under strong acidic and alkaline conditions. When applied to spoiled shrimp, an evident color change from yellow to brown was observed, suggesting it could serve as an easy-to-use, non-destructive visual indicator system for real-time food monitoring.

Polysaccharides from 14 batches of Polygonatum sibiricum (PS), P. cyrtonema (PC), P. kingianum (PK) and P. odoratum (PO) were compared based on high-performance gel permeation chromatography (HPGPC) saccharide mapping, monosaccharide composition, molecular weight distribution and Fourier transform infrared (FTIR) spectra. Results showed that polysaccharides from PS, PC and PK exhibited two different molecular weight fractions and that one was more than 4.1 × 105 Da (P1) and the other was 2.8-5.4 × 103 Da (P2); while the polysaccharides from PO displayed only one main peak (P2). The analysis of monosaccharide composition and HPGPC saccharide mapping proved that P1 and P2 were composed of pectins and fructans, respectively. The FTIR spectra indicated that these polysaccharides had different degrees of esterification. This study provided a systematic profiling of polysaccharides of Polygonatum spp. and was helpful in understanding the varied functions of different Polygonatum spp., based on chemical composition.

In this study, TiO2 nanocrystals were synthesized in the scaffold of cellulose nanocrystal (CNC) using in situ hydrolysis, where the morphology and size of TiO2 was controlled by CNC’s functional groups and surface charge. The resulting TiO2/CNC nanocomposites showed a superior photocatalytic activity for Cr(VI) reduction under visible light (λ > 420 nm) due to the combined effects of small TiO2 size and ligand-to-metal charge transfer (LMCT) complex between CNC and TiO2. It was found that the charge-enriched CNC not only acted as a template to direct the crystal growth of TiO2, but also played essential roles on light harvesting and charge transfer thereby promoting the photoreduction of Cr(VI). The demonstrated system represents a unique pathway to develop a lower cost and efficient purification material for remediation of Cr(VI).

A glycosaminoglycan was isolated from the sea cucumber Holothuria coluber (HcFG). A series of oligosaccharide fragments (dp range 3–11) were prepared from its β-eliminative depolymerized product (dHcFG). Extensive NMR characterization of the oligosaccharides indicated the D-GlcA-β1,3-D-GalNAc4S6S repeating disaccharide backbone was substituted by monosaccharide branches comprising of Fuc2S4S, Fuc3S4S and Fuc4S, linked to O-3 of D-GlcA. For the prevailing Fuc3S4S at nonreducing end of dHcFG, the β-eliminative depolymerization process of HcFG was compared with those of the FGs from Actinopyga miliaris (AmFG, branched with Fuc3S4S) and Stichopus variegatus (SvFG, branched with Fuc2S4S). The result suggested that D-GlcA substituted with Fuc3S4S was more susceptible to depolymerization than that with Fuc2S4S. It might be due to the larger steric hindrance effects from Fuc2S4S on the esterification of GlcA. Biological assays confirmed that the minimum chain length (dp8), regardless of the Fuc branch types, was required for the potent anti-iXase and anticoagulant activities in FG fragments.

The standard chemotherapy is facing the challenges of lack of cancer selectivity and development of drug resistance. Currently, with the application of nanotechnology, the rationally designed nanocarriers of chondroitin sulfate (CS) have been fabricated and their unique features of low toxicity, biocompatibility, and active and passive targeting made them drug delivery vehicles of the choice for cancer therapy. The hydrophilic and anionic CS could be incorporated as a building block into- or decorated on the surface of nanoformulations. Micellar nanoparticles (NPs) self-assembled from amphiphilic CS-drug conjugates and CS-polymer conjugates, polyelectrolyte complexes (PECs) and nanogels of CS have been widely implicated in cancer directed therapy. The surface modulation of organic, inorganic, lipid and metallic NPs with CS promotes the receptor-mediated internalization of NPs to the tumor cells. The potential contribution of CS and CS-proteoglycans (CSPGs) in the pathogenesis of various cancer types, and CS nanocarriers in immunotherapy, radiotherapy, sonodynamic therapy (SDT) and photodynamic therapy (PDT) of cancer are summarized in this review paper.

Glycoscience is an interdisciplinary field, which leads to different industrial applications derived from physicochemical and/or biological properties of carbohydrates. This study aims to evaluate how glycoscience may act as a driving force to make research innovative and sustainable in industrial and/or commercial areas. To this end, we rationalized the two main properties of carbohydrate molecules into three main value chains. The regional biomass (sugar, starch, wood) value-chain exploits the physicochemical properties of carbohydrates; the glycomics explores the biological functions of carbohydrates and the non-regional biomass (microbial, pectin, chitin) value-chain exploits the two properties. Each value-chain harbors one or more niches prone to or at an emerging stage of development, and all these niches share a techno-scientific push approach aimed at developing high value-added products with new functionalities, new bioactive glycans, and new enabling technologies that will lead to new applications and possible novel therapies and diagnostics tools.

Prosopis juliflora is an invasive plant distributed throughout the world and presents metabolites of interest for cosmetology. The aim of this work was to develop a new polysaccharide-based ingredient from P. juliflora and analyze its application in a solid core formulation that upon contact with water instantly forms a gel to improve moisturizing and anti-aging skin properties. Purified extracts by gel chromatography were characterized by NMR and LC-DAD-MS-MS. The in vitro and in vivo safety, antioxidant activity, formulation development and clinical evaluation were performed. The extract was characterized as containing an α-glucan and phenolics. It was non-cytotoxic, non-phototoxic and no skin reactions were observed in vivo. Antioxidant activity were present through different mechanisms. Clinical evaluation reinforced the potential of P. juliflora in skin hydration and microrelief improvement. This innovative form proved to be a prototype of a new product and the first study of an α-glucan as a cosmetic ingredient.

Glycosaminoglycans (GAGs) are large, complex carbohydrate molecules that interact with a wide range of proteins involved in physiological and pathological processes. Several naturally derived GAGs have emerged as potentially useful therapeutics in clinical applications. Natural polysaccharides, however, generally have high molecular weights with a degree of polydispersity, making it difficult to investigate their structural properties. In this study, we establish a free-radical–mediated micro-reaction system and use hydrophilic interaction chromatography (HILIC)–Fourier transform mass spectrometry (FTMS) to profile the degraded products of various types of GAGs, heparin, chondroitin sulfate A, NS-heparosan, and oversulfated chondroitin sulfate (OSCS), to reveal the free-radical degradation mechanism of GAGs. The results show that the bulk fragments of GAGs generated by free-radical degradation can maintain their basic structural units and sulfate substituents. In addition, an abundance of oligomers modified with oxidation at their reducing ends or by dehydration also appeared. We discovered that these modifications were related in terms of the degree of sulfation and the α- or β-linkage of HexNY (Y = SO3- or Ac), and especially that the different linkage of the disaccharide unit is the main factor in modification. In addition, the method based on micro-free-radical reaction and HILIC-FTMS is both effective and sensitive, thus suggesting its broad practical value for the structural characterization and in the biological structure-function studies of GAGs.

Various nanoparticles have been developed for tumor-targeted drug delivery. However, nanoparticles with effective targeting and intelligent release capacity are still deficient. Herein, we present new pH-responsive and neutral charged nanoparticles for tumor-targeted anticancer drug delivery. Oxidized starch was synthesized and simultaneously modified by cholesterol and imidazole to obtain amphiphilic cholesterol/imidazole modified oxidized-starch (Cho-Imi-OS). Cho-Imi-OS easily self-assembled into nanoparticles by dialysis. Curcumin was selected as model drug to be encapsulated into the hydrophobic core of nanoparticles. The results showed that curcumin would effectively accumulate in cancer cells by encapsulating into the nanoparticles owing to the nano-sized structure and near neutral charged property of nanoparticles. Curcumin was released faster at pH 5.5 than that at pH 7.4 from the curcumin-loaded nanoparticles (Cur-NPs), indicating the pH-triggered release capacity of Cur-NPs after endocytosis by endosomes since the pH is low to 5.0∼6.0 in endosomes. Naturally, Cur-NPs showed significantly strong inhibitory effect on cancer cells.

A new water-soluble polysaccharide UPP was obtained from Ulva Pertusa and its structure was studied. The structural analysis results showed that UPP was composed of eight residues. The bone structure of UPP was →4)-β-D-Xylp-(1→4)-α-L-Rhap3S(1→3,4)-β-L-Arap(1→3)-α-L-Rhap(1→2,4)-α-L-Rhap(1→4)-α-D-Galp(1→ and there were two main branches. The branch structure at the 3-position of 1,3,4-β-L-Arap was →3,4)-β-L-Arap(1→4)-β-D-Glcp3Me(1→4)- β-D-GlcpA(1→ and the branch structure at 2-position of 1,2,4-α-L-Rhap was →4)-β-D-GlcpA(1→4)-β-D-Xylp(1→. In addition, the physicochemical property analysis showed that UPP was a semi-crystalline polymer and there was no triple-helical structure. This structure analysis of UPP will be beneficial for future research on the algal polysaccharides.

Spent coffee grounds are wastes generated annually worldwide in significantly large amounts in the soluble coffee industry and in household and commercial beverage preparation. Although spent coffee grounds are rich in several classes of compounds, predominantly polysaccharides, profitable applications have not yet been effectively implemented for such wastes. Thus, it was the aim of this study to verify the feasibility of producing biopolymeric films from the polysaccharide-rich fraction of spent coffee grounds, obtained by alkaline hydrogen peroxide treatment of the coffee waste. Produced films were characterized for their physicochemical, barrier and mechanical properties and these properties were comparable to those of similar polysaccharides films from the literature.

In this study, the impact of drug and hydroxypropyl methylcellulose acetate succinate (HPMCAS) grades physicochemical properties on extrusion process, dissolution and stability of the hot melt extruded amorphous solid dispersions (ASDs) of nifedipine and efavirenz was investigated. Incorporation of drugs affected the extrusion temperature required for solid dispersion preparation. Differential scanning calorimetry and powder X-ray diffraction studies confirmed the amorphous conversion of the drugs in the prepared formulations. The amorphous nature of ASDs was unchanged after 3 months of stability testing at 40 °C and 75% relative humidity. The dissolution efficiency of the ASDs was dependent on the log P of the drug. The inhibitory effect of HPMCAS on drug precipitation was dependent on the hydrophobic interactions between drug and polymer, polymer grade, and dose of the drug. The dissolution rates were dependent on the solubility and hydrophilicity of the polymer grade.

The cell wall polysaccharide ulvan was isolated from two species of the seaweed Ulva collected along the Swedish west coast. Acidic extraction was benchmarked against hot water extraction with enzymatic purification and against commercial ulvan. Extracted ulvan contained 11-18% g/g of ash, some protein (up to 1.3% g N/g) but minimal colored impurities. The ulvans had high molecular weights (660,000-760,000 g/mol) and were composed of 77-79% g/g carbohydrates, mainly rhamnose, xylose, glucose, glucuronic acid, and iduronic acid. The extraction protocol and the ulvan source strongly impact the molecular weight and the chemical composition. Acidic extraction caused almost complete desulfation of the isolated ulvan while the other method preserved a significant degree of SO3 substituents. Elemental analysis of ash remaining after thermal degradation showed presence of common mineral elements such as Na, Ca, Mg, Al, and K, but none of the heavy metals Pb, Hg, or As.

The objective of this study was to demonstrate the validity of dynamic semi-dry heat reaction (SDHR) by investigating the effects of static and dynamic SDHR on the characteristics of starch citrates. The starch (normal and waxy corn)-citric acid (CA) mixture was heated in a convection oven (static mode) or a twin-screw extruder without a die (dynamic mode). The ester bonds of starch citrates were confirmed by FT-IR, and their molar degree of substitution did not differ between the reaction modes for the tested starch genotypes. Starch citrates by dynamic SDHR exhibited higher relative crystallinity, resistant starch content, solubility, swelling power, and gelatinization compared to those by static SDHR. Although static SDHR did not show a viscosity development during pasting, dynamic SDHR increased their pasting viscosities. Overall, these results suggest that dynamic SDHR could improve the defects (i.e., lack of solubility, swelling, and pasting attributes) of the traditional starch citrates.

Blending two biodegradable aliphatic polyesters with complementary bulk properties is an easy way of tuning their final properties. In this work, the ductile poly(butylene succinate) was mixed with polylactide, and as expectable, the blends show improved toughness with sharply reduced strengths. The pristine cellulose nanofibers were then used as the reinforcement for the blends. It is found that most nanofibers are dispersed in the polylactide phase because polylactide has better affinity to nanofibers, and the lower viscosity level of polylactide also favors driving nanofibers into the continuous polylactide phase during melting mixing. In this case, the strength and rigidity losses resulted from the presence of soft poly(butylene succinate) phase are compensated to some extent. To further improve mechanical properties, a two-step approach (reactive processing of blends, followed by the incorporation with nanofibers) was developed. This work provides an interesting way of fabricating fully biodegradable composites with well-balanced mechanical performance.

A novel bio-based flame retardant, ammonium phosphate starch carbamates (APSC) was synthesized from starch, phosphoric acid and urea to achieve better thermal stability and char formation. Flame retardant expandable polystyrene foams (EPS) were prepared by coating method with APSC. The fire resistance evaluation of EPS composites by limiting oxygen index (LOI), vertical burning (UL-94) and cone calorimeter tests indicated that the addition of 47 wt.% of APSC enhanced the LOI from 17.6% to 35.2%, with V-0 rating in UL-94, and decreased the peak heat release rate from 666 kW/m2 to 316 kW/m2. Moreover, the total smoke production was also sharply decreased from 70 m2 of pure EPS to 17 m2. By the presence of APSC, the substantial char formation prevented the heat and oxygen transfer, and interrupted the releasing of flammable products, thus protecting the EPS foam from burning.

The study investigated chitosan coated nanostructured lipid carriers (NLCs) for oral delivery of albendazole in treatment of trichinellosis. NLCs comprised precirol and oleic acid with Tween and Span 80. Dicetylphosphate was used as charging agent to allow chitosan coating. Trichinella spiralis infected mice were used and albendazole suspension, coated or uncoated NLCs were orally administered at different stages of infection. NLCs were spherical with size of 188 and 200 nm for coated and uncoated NLC, respectively. Treatment during intestinal phase reduced worm count with NLCs showing better rank. This was reflected further by reduced larvae count and improved histopathological features. Starting treatment in the migrating phase reduced larval count by 62.9, 99.6 and 89.5% after administration of suspension, coated and uncoated NLCs, respectively. The same rank was recorded for the encysted phase. NLCs enhanced the efficacy of albendazole against Trichinella spiralis compared with suspension with chitosan coated NLCs being superior.

In the present study, a type of bioconjugate was synthesized by post modification of alginate by conjugating temperature-responsive poly(ε-caprolactone-co-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-lactide) and O-phosphorylethanolamine as phosphorylation functional groups. Freely flowing bioconjugate sols at low temperature can transform to stable viscoelastic gels at the physiological temperature (37 °C). Subcutaneous administration of temperature-responsive bioconjugate sols into the dorsal region of Sprague-Dawley rats formed in situ hydrogel. In situ formation of bioconjugate gels in stimulated body fluids at 37 °C showed nucleation and hydroxyapatite mineral growth. Furthermore, hydroxyapatite growth was also found in in vivo gels, which suggested the potential of alginate-based bioconjugate gels as a scaffold for bone engineering. Bone morphogenetic protein 2 (BMP-2)-loaded bioconjugate formed stable gel in vivo, and demonstrated sustained release. BMP-2-loaded bioconjugates exhibited in situ biomineralization in vivo. These results imply that the in situ formation of injectable biomimetic materials has potential for bone tissue engineering applications.

In this study, an injectable and self-healing hydrogel based on the boronic ester dynamic covalent bond between phenylboronic acid modified hyaluronic acid (HA-PBA) and the commercially available poly (vinyl alcohol) (PVA) is prepared and should have multi-functions for biomedical applications. The hydrogels were rapidly formed under mild conditions, and the rheological properties and in vitro degradation were systematically characterized. The HA-based hydrogels possessed good injectability and self-healing properties because of the dynamic bond. Moreover, due to the sensitivity of boronic ester to the biologically relevant concentration of hydrogen peroxide (H2O2), a major reactive oxygen species (ROS), the injectable hydrogel could be used as a H2O2/ROS responsive drug delivery system. The hydrogels supported good viability of encapsulated neural progenitor cells (NPC) and protected NPC from ROS induced damage in vitro when H2O2 was present in the media. The dynamic hydrogels were further applied as bio-inks for 3D printing/bioprinting. Overall, this facilely prepared dynamic hydrogel based on HA-PBA and PVA may have many potential biomedical applications, including drug delivery, 3D culture of cells, and 3D bioprinting.

Polyelectrolyte nanocomposite hydrogels (NHGs) were synthesized. NHGs were formed from a polymer matrix composed of a cationic, anionic, and alkylated chitosan polymer modified with vinyl groups (ChAV) to achieve greater crosslinking. Cationic and anionic clays montmorillonite and hydrotalcite, respectively were used as nanofillers to introduce electrostatic interaction with the matrix. NHGs were obtained via in situ polymerization. The ChAV and NHGs were then characterized. Based on X-ray diffraction and transmission electron microscopy results, the morphology of the nanocomposite was generally intercalated with some nanocomposites showing exfoliation. Rheological studies revealed improvements in shear modulus of NHGs with respect to hydrogel without clay. Lower relaxation times were noted as the clay content increased and it was attributed to the interactions between the clay sheets and the polymer. In conclusion the rheological properties of the material are improved with the addition of clay and the interactions present with the polymer matrix.

The aim of this study was to develop novel nanofibrous membranes based on the quaternary ammonium N-halamine chitosan (CSENDMH) and polyvinyl alcohol (PVA) for antibacterial and hemostasis wound dressing. To improve the antimicrobial properties of nanofibrous membranes, a new chitosan-quaternary ammonium N-halamine derivative was successfully synthesized, and the structure was analyzed by 1H NMR and 13C NMR, fourier transform infrared (FTIR) spectroscopy, and elemental analysis. The morphological and water absorption ability studies showed that the membrane had a uniform bead-free network and high porosity structure like natural extracellular matrix as well as high hydrophilicity. For in vitro evaluation of the hemostatic effect, the membranes showed excellent blood clotting capacity, especially the PVA/CSENDMH membranes. The antimicrobial assay demonstrated excellent antibacterial activity of nanofibrous membranes against both gram-negative and gram-positive bacteria. Furthermore, the cytocompatibility assay results indicated that human fibroblasts could adhere and proliferate on the membranes, thus corroborating their biocompatibility.

We previously reported that waxy potato and corn starch amylopectin pastes undergo a shear-thickening behavior that occurs at a low shear rate range of 5 to 25 s-1, and that the effect did not occur for waxy rice starch. Here, we show that the same gelatinized potato amylopectin subjected to a prolonged shear rate of 20 s-1 for 24 h at 5 °C forms a highly viscous gel having a 4-fold higher number of double-helices than without shear. Shear-induced starch retrograded aggregates began forming within 20 min of treatment. Amylopectin double-helices melted between 40 to 75 °C resulting in a steep decrease in the storage modulus, indicating that gel formation was caused by intermolecular double-helices. Thus, a new phenomenon is reported whereby a waxy potato amylopectin paste, in the presence of long-term low shear, forms double-helical aggregated structures that considerably affects the material’s rheological properties.

In mice, porphyran extracted from Pyropia yezoensis exerts anti-inflammatory effects and suppresses lipopolysaccharide (LPS)-induced immune activation and sepsis. Here, we investigated inhibition of LPS-induced activation of human immune cells by porphyran and the underlying mechanisms. We demonstrated that porphyran may inhibit LPS-induced proinflammatory cytokine production in peripheral blood mononuclear cells, monocyte-derived dendritic cells, and peripheral blood dendritic cells. We also observed that porphyran-mediated LPS-induced activation of DC suppressed syngeneic T cell proliferation, resulting in reduced production of interferon-γ. The mechanism of LPS-induced immune cell activation requires the activation of toll like receptor 4 following binding of LPS to myeloid differentiation factor 2 (MD2). Additionally, we show that porphyran competes with LPS for binding to MD2 and thereby suppresses immune cell activation. Porphyran may, therefore, be a promising therapeutic candidate for the treatment of endotoxin-mediated septic shock and inflammation in humans.

The binary nanocomposites blended by carboxymethyl cellulose (CMC) and SiO2 nanoparticles were constructed to prepare the films with superior thermal stability and flame retardant properties. The incorporation of cellulose nanofibers(CNFs) and SiO2 nanoparticles were followed to prepare ternary nanocomposite films exhibiting excellent mechanical properties. The mechanism and chemical reaction of the thermal decomposition for the CMC/SiO2 composite membrane were proposed, which showed that the mass residuals were Na2CO3, SiO2 and Na2SiO3, Na2CO3 when the content of the SiO2 nanoparticles was lowered and higher than 9.6%, respectively. Compared with the pure CMC, micro combustion calorimeter (MCC) showed that the total heat release (THR) and the peak heat release rate (PHRR) both decreased from 6.4 kJ/g to 5.8 kJ/g, 134 w/g to 27 w/g, respectively. Moreover, mechanical properties of CMC/CNFs/SiO2 membrane showed that the toughness and rigidity of the nanocomposites increased by 56.0% and 63.0% on the basis of CMC, respectively.

Chondroitin sulfate is a linear glycosaminoglycan widely distributed as an important extracellular matrix component of mammalian cells. It participates in numerous pathological processes, however, illustration of its diverse biological roles is hampered by the unavailability of structurally defined chondroitin polymers and their derivatives. Herein, we report a novel homogeneous chondroitin polymers synthetic strategy which combines stepwise oligosaccharides synthesis with one-pot homogeneous chondroitin chain polymerization. Exogenous trisaccharide was proved to be the necessary acceptor for PmCS-catalyzed homogeneous chondroitin polymers synthetic reactions. The strategy exhibited a well-controlled relationship between the final sugar chain length and the molar ratios of reaction substrates that could synthesize homogenous chondroitin polymers with unprecedented narrow molecular weight distribution. More importantly, the strategy was further expanded to synthesis of unnatural zwitterionic and N-sulfonated chondroitin polymers by incorporation of sugar nucleotide derivatives into the synthetic approach.

Glioblastoma (GBM), the most common and extremely lethal type of brain tumor, is resistant to treatment and shows high recurrence rates. In the last decades, it is indicated that standard two-dimensional (2D) cell culture is inadequate to improve new therapeutic strategies and drug development. Hence, well-mimicked three-dimensional (3D) tumor platforms are needed to bridge the gap between in vitro and in vivo cancer models. In this study, bacterial cellulose nano-crystal (BCNC) containing polycaprolactone (PCL) /gelatin (Gel) nanofibrous composite scaffolds were successfully fabricated by electrospinning for mimicking the extracellular matrix of GBM tumor. The fiber diameters in the nanofibrous matrix were increased with an increased concentration of BCNC. Moreover, fiber morphology changed from the smooth formation to the beaded formation by increasing the concentration of the BCNC suspension. In-vitro biocompatibilities of nanofibrous scaffolds were tested with U251 MG glioblastoma cells and improved cell adhesion and proliferation was compared with PCL/Gel. PCL/Gel/BCNC were found suitable for enhancing axon growth and elongation supporting communication between tumor cells and the microenvironment, triggering the process of tumor recurrence. Based on these results, PCL/Gel/BCNC composite scaffolds are a good candidate for biomimetic GBM tumor platform.

The synergistic plasticization/compatibilization effect of poly(ethylene glycol)/glycerol is reported for poly(vinyl alcohol) (PVA)/chitosan blends. The optimum concentration of PEG was first determined by preparation and characterization of PVA/PEG blends at different ratios (9:1, 6:1 and 3:1). The PVA/chitosan blends, plasticized with PEG, glycerol, and their combination, were also prepared and characterized. Fourier transform infrared results suggested that PEG enhances the compatibility of PVA/chitosan blends. This claim was further confirmed by the morphological results. However, PEG had a detrimental effect on the crystallinity of PVA/chitosan blends. The combination of glycerol and PEG caused a five-time enhancement in the elongation at break values as compared with the blend plasticized with glycerol. The antibacterial properties against E. coli were also evaluated. All in all, the high antibacterial properties of the blend films along with good mechanical and morphological properties could be beneficial in wound dressing and food packaging applications which need further investigation.

In this study, the reinforced ZnONPs/ rosemary essential oil-incorporated zein nanofibers with κ-carrageenan (Z/KC/ZnONPs/RE) were fabricated using the electrospinning technique for application in food packaging. The SEM images of Z/KC/ZnONPs/RE nanofiber displayed bead-free homogeneous morphology that its average fiber diameter was 672 ± 240 nm. The formation of new hydrogen bonds by addition of κ-carrageenan and active agents was approved by FT-IR and DSC structural conformations. The Z/KC/ZnONPs/RE nanofiber exhibited satisfactory thermal and mechanical properties, as well as high surface hydrophobicity. In addition, the Z/KC/ZnONPs/RE sample showed inhibition activity against S. aureus (18.5 ± 1.9 mm) and E. coli (14.7 ± 1.5 mm) bacteria. The DPPH scavenging activity of Z/KC/ZnONPs/RE nanofiber was 54.5 ± 3.6%. Additionally, the fabricated nanofibers showed no cell cytotoxicity, indicating their good biocompatibility. Thus, we believe that the fabricated Z/KC/ZnONPs/RE electrospun nanofiber is a potential candidate for using as an active layer in food packaging system.

Novel nanomaterials have been developed for antimicrobial and wound healing applications. Here, we report the preparation of a polyvinyl alcohol/chitosan (PVA/CS) nanofiber with carboxymethyl chitosan nanoparticles (CMCS-OH30 NPs) encapsulating the antibacterial peptide OH-CATH30 (OH-30). The PVA/CS nanofibers containing OH-30 NPs (NP-30-NFs) obtained via electrospinning could achieve a secondary embedded OH-30. The effect of NP-30-NFs on the release of OH-30 was investigated through high-performance liquid chromatography. The antibacterial activities of NP-30-NFs against Escherichia coli and Staphylococcus aureus were studied by bacterial plate counting. NP-30-NFs containing different concentrations of NPs were applied to mouse skin wounds to determine their effectiveness in promoting wound healing. Results showed that NP-30-NFs exhibited antibacterial properties and promoted skin wound healing.

Complex permittivity spectra were obtained herein by performing broadband terahertz (THz) spectroscopy on cellulose, paramylon, and paramylon ester. Absorption peaks observed for cellulose and paramylon at approximately 3 THz are attributed to hydrogen bonds. In addition, a broad absorption peak around 2 THz was observed for all the polymers, demonstrating a general feature of polymer glasses derived from weak interatomic van der Waals forces. The boson peak was observed for cellulose and paramylon ester. The boson peak frequency for cellulose nearly equaled that for glassy glucose—a unit structure of the cellulose polymer. Additionally, the insensitivity of cellulose to the polymerization degree was consistent with recent results obtained via molecular dynamics simulations. In contrast, the boson peak frequency of paramylon ester was markedly smaller than that of cellulose. These results demonstrate the importance of hydrogen bonds as determinants of the boson peak frequency.

A series of biocompatible and non- toxic polysaccharide molecules have been successfully fabricated and explored their potential application for scavenging the carbonyl species in vitro. These macromolecules were dextrans with different hydrazide substitution ratios determined by TNBS assay, NMR and FTIR characterization. The colorimetric assay had demonstrated that these macromolecules could effectively scavenge acrolein, oxidized bovine serum albumin (BSA) in buffer solutions as well as carbonyl proteins from serum. The scavengers could achieve twice more scavenging effects for modified dextrans with high molecular weight (Mw = 100000) than those of low ones (Mw = 40000) with the same substitution ratio. Protein gel electrophoresis confirmed that the formation of the complex between carbonyls and modified dextrans resulted in appearance of slower bands. It also revealed that such macromolecules could protect cultured cells against the toxicity of acrolein or its derivatives. The proposed macromolecules indicated a very promising capability as scavengers for oxidative stress plus its derivatives without side effects.

The aim of this study was to use of bacterial cellulose/polypyrrole/TiO2-Ag (BC/PPy/TiO2-Ag) nanocomposite film to detect and measure the growth of 5 pathogenic bacteria. For this purpose, at first, 13 BC/PPy/TiO2-Ag films were fabricated, then bacterial suspensions were prepared according to McFarland standard. The results showed that by increasing the bacterial concentration, the electrical resistance of sensors was decreased and there was a relation between bacterial concentration and bacterial type with electrical resistance change of sensors. The obtained data showed that the sensitivity of the sensors was increased with increasing the concentration of polypyrrole and TiO2-Ag. FT-IR and SEM tests were performed to investigate the interaction between nanoparticles and determine the size of nanoparticles. The BC/PPy/TiO2-Ag biosensors are portable and the response time of these sensors is very short for target analysis. Therefore, these sensors have the potential to improve biological safety as diagnostic tools.