Polymers

Research

Jump to: Review

14 pages, 4151 KiB

Open AccessEditor’s ChoiceArticle

Antimony Removal from Water by a Chitosan-Iron(III)[ChiFer(III)] Biocomposite

by Byron Lapo, Hary Demey, Tanya Carchi and Ana María Sastre

Polymers 2019, 11(2), 351; https://doi.org/10.3390/polym11020351 - 18 Feb 2019

Cited by 25 | Viewed by 5193

Abstract

The presence of antimony(III) in water represents a worldwide concern, mainly due to its high toxicity and carcinogenicity potential. It can be separated from water by the use of sustainable biopolymers such as chitosan or its derivatives. The present study applied chitosan modified [...] Read more.

The presence of antimony(III) in water represents a worldwide concern, mainly due to its high toxicity and carcinogenicity potential. It can be separated from water by the use of sustainable biopolymers such as chitosan or its derivatives. The present study applied chitosan modified with iron(III) beads to Sb(III) removal from aqueous solutions. The resulting material performed with a high adsorption capacity of 98.68 mg/g. Material characterization consisted of Raman spectroscopy (RS), X-ray diffraction (XRD), scanning electron microscope observations (SEM-EDX), Fourier transform infrared spectroscopy (FTIR) and point of zero charge (pH_pzc). The adsorption study included pH study, effect of initial concentration, kinetics, ion effect, and reusability assessment. The RS, XRD, and FTIR results indicated that the main functional groups in the composite were related to hydroxyl and amino groups, and iron oxyhydroxide species of α-FeO(OH). The pH_pzc was found to be 7.41. The best adsorption efficiency was set at pH 6. The equilibrium isotherms were better fitted with a non-linear Langmuir model, and the kinetics data were fitted with a pseudo-second order rate equation. The incorporation of iron into the chitosan matrix improved the Sb(III) uptake by 47.9%, compared with neat chitosan (CS). The material did not exhibit an impact in its performance in the presence of other ions, and it could be reused for up to three adsorption–desorption cycles. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

18 pages, 2266 KiB

Open AccessEditor’s ChoiceArticle

Sorption and Desorption Studies of Pb(II) and Ni(II) from Aqueous Solutions by a New Composite Based on Alginate and Magadiite Materials

by Keltoum Attar, Hary Demey, Djamila Bouazza and Ana Maria Sastre

Polymers 2019, 11(2), 340; https://doi.org/10.3390/polym11020340 - 15 Feb 2019

Cited by 49 | Viewed by 4951

Abstract

A new composite material based on alginate and magadiite/Di-(2-ethylhexyl) phosphoric acid (CAM-D2EHPA) was successfully prepared by previous impregnation of layered magadiite with D2EHPA extractant, and then immobilized into the alginate matrix. Air dried beads of CAM-D2EHPA were characterized by FTIR and SEM–EDX techniques. [...] Read more.

A new composite material based on alginate and magadiite/Di-(2-ethylhexyl) phosphoric acid (CAM-D2EHPA) was successfully prepared by previous impregnation of layered magadiite with D2EHPA extractant, and then immobilized into the alginate matrix. Air dried beads of CAM-D2EHPA were characterized by FTIR and SEM–EDX techniques. The sorbent was used for the separation of lead and nickel from nitrate solutions; the main parameters of sorption such as contact time, pH of the solution, and initial metal concentration were studied. The beads recovered 94% of Pb(II) and 65% of Ni(II) at pH 4 from dilute solutions containing 10 mg L⁻¹ of metal (sorbent dosage, S.D. 1 g L⁻¹). The equilibrium data gave a better fit using the Langmuir model, and kinetic profiles were fitted using a pseudo-second order rate equation. The maximum sorption capacities obtained (at pH 4) were 197 mg g⁻¹ and 44 mg g⁻¹ for lead and nickel, respectively. The regeneration of the sorbent was efficiently carried out with a dilute solution of HNO₃ (0.5 M). The composite material was reused in 10 sorption–elution cycles with no significant differences on sorption uptake. A study with synthetic effluents containing an equimolar concentration of both metals indicated a better selectivity towards lead ions. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

12 pages, 2101 KiB

Open AccessArticle

Comparisons of Functional Properties of Polysaccharides from Nostoc flagelliforme under Three Culture Conditions

by Shi-Gang Shen, Ya-Hui Lin, Dong-Xue Zhao, Yi-Kai Wu, Rong-Rong Yan, Hua-Bing Zhao, Zhi-Lei Tan, Shi-Ru Jia and Pei-Pei Han

Polymers 2019, 11(2), 263; https://doi.org/10.3390/polym11020263 - 4 Feb 2019

Cited by 23 | Viewed by 4201

Abstract

Nostoc flagelliforme is an edible cyanobacterium with excellent food and herbal values. It has been used as food in China for more than 2000 years. Many studies have been focused on improving the yield and bioactivity of Nostoc flagelliforme polysaccharides although these have [...] Read more.

Nostoc flagelliforme is an edible cyanobacterium with excellent food and herbal values. It has been used as food in China for more than 2000 years. Many studies have been focused on improving the yield and bioactivity of Nostoc flagelliforme polysaccharides although these have ignored the functional properties. In this study, we extracted and purified three polysaccharides (WL-CPS, NaCl-CPS and Glu-CPS) from Nostoc flagelliforme under normal, salt stress and mixotrophic culture conditions, respectively, in order to change the physicochemical properties of polysaccharides with the aim of obtaining better functional properties. Both salt stress and mixotrophic culture conditions increased the specific yield of polysaccharides. Their functional properties were comparatively investigated and the results showed that NaCl-CPS exhibited the highest emulsification activity and flocculation capability, which was also higher than that of some commercial products. In contrast, Glu-CPS exhibited the highest water and oil holding capacities, foaming property, intrinsic viscosity and bile acids binding capacity. Our results indicated that both NaCl-CPS and Glu-CPS could be considered to be functional polysaccharides according to their respective characteristics, which have great potential in numerous applications, such as food, pharmaceutical, cosmetic, chemical and mineral industries. These findings also demonstrated the potential application of the proper regulation of culture conditions in the development of polysaccharides with desired functional properties. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

11 pages, 2273 KiB

Open AccessArticle

Solubility Difference between Pectic Fractions from Creeping Fig Seeds

by Ri-si Wang, Xiao-hong He, Hong Lin, Rui-hong Liang, Lu Liang, Jun Chen and Cheng-mei Liu

Polymers 2019, 11(1), 159; https://doi.org/10.3390/polym11010159 - 17 Jan 2019

Cited by 10 | Viewed by 4895

Abstract

Crude water-extracted pectin (WEP) isolated from creeping fig seeds were mainly fractionated into WEP-0.3 and WEP-0.4 fractions. Fractions were confirmed to be nonstarch, nonreducing sugars, nonpolyphenols and protein-unbounded acidic polysaccharides. Interestingly, a significant difference in solubility was found between WEP-0.3 (higher solubility than [...] Read more.

Crude water-extracted pectin (WEP) isolated from creeping fig seeds were mainly fractionated into WEP-0.3 and WEP-0.4 fractions. Fractions were confirmed to be nonstarch, nonreducing sugars, nonpolyphenols and protein-unbounded acidic polysaccharides. Interestingly, a significant difference in solubility was found between WEP-0.3 (higher solubility than WEP) and WEP-0.4 (remarkably insoluble), which was consistent with the amorphous and porous sponge-like structure of WEP-0.3 as well as the crystalline and dense rod-like state of WEP-0.4. However, the result of the FT-IR spectra was contradicted by the solubility of WEP-0.4, which possessed the lowest degree of methoxylation and ought to possess the highest solubility. Through mineral analysis, a considerably high content of Ca²⁺ was found in WEP-0.4, suggesting that the low solubility of WEP-0.4 was probably attributable to the formation of microgels during dialysis. Therefore, metal divalent cations in the dialysate were suggested to be depleted for the dialysis of low methoxyl pectin. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

17 pages, 3312 KiB

Open AccessArticle

Long Term and Large-Scale Continuous Studies on Zinc(II) Sorption and Desorption on Hybrid Pectin-Guar Gum Biosorbent

by Agata Jakóbik-Kolon, Joanna Bok-Badura, Andrzej Milewski and Krzysztof Karoń

Polymers 2019, 11(1), 96; https://doi.org/10.3390/polym11010096 - 8 Jan 2019

Cited by 14 | Viewed by 3246

Abstract

Pectin-guar gum biosorbent was tested for zinc(II) ions removal in column process. Sorption–desorption experiments were performed in laboratory and at larger scale. The breakthrough and elution curves were obtained for various conditions. The Bed Depth Service Time model was tested for utility in [...] Read more.

Pectin-guar gum biosorbent was tested for zinc(II) ions removal in column process. Sorption–desorption experiments were performed in laboratory and at larger scale. The breakthrough and elution curves were obtained for various conditions. The Bed Depth Service Time model was tested for utility in data estimation. Possibility of sorbent reuse and its lifetime was examined in 20 repeated sorption–desorption cycles. Finally, tests were repeated for real wastewater from galvanizing plant, giving satisfactory results. The effectiveness of Zn(II) sorption happened to be dependent on process parameters; tests have proved that it increased with increasing bed height and with decreasing flow rate or grain size. For an initial zinc concentration of 30 mg/L, even 2096 mL of zinc solution could be purified in small scale experiment (2 g of fine grain sorbent and flow rate 60 mL/h) or 5900 L in large-scale (16 kg of large grain sorbent and flow rate 45 L/h). This allowed for 40-fold or 49-fold zinc increases in concentration in one sorption–desorption cycle. The most successful results are meant that at least 20 sorption–desorption cycles could be performed on one portion of biosorbent without loss of its effectiveness, large-scale tests for real wastewater from galvanizing plant gave satisfactory results, and that the form and mechanical stability of our sorbent is suitable for column usage with flow rates applicable in industry. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

14 pages, 3246 KiB

Open AccessArticle

The First Synthesis of Periodic and Alternating Glycopolymers by RAFT Polymerization: A Novel Synthetic Pathway for Glycosaminoglycan Mimics

by Masahiko Minoda, Tomomi Otsubo, Yohei Yamamoto, Jianxin Zhao, Yoshitomo Honda, Tomonari Tanaka and Jin Motoyanagi

Polymers 2019, 11(1), 70; https://doi.org/10.3390/polym11010070 - 5 Jan 2019

Cited by 9 | Viewed by 4756

Abstract

This study concerned the controlled synthesis of periodic glycopolymers by reversible addition-fragmentation chain transfer (RAFT) copolymerization. To this end, maltose- and lactose-substituted vinyl ethers (MalVE and LacVE, respectively) and maltose-substituted maleimide (MalMI) were newly synthesized. RAFT copolymerization of MalVE and ethyl maleimide (EtMI) [...] Read more.

This study concerned the controlled synthesis of periodic glycopolymers by reversible addition-fragmentation chain transfer (RAFT) copolymerization. To this end, maltose- and lactose-substituted vinyl ethers (MalVE and LacVE, respectively) and maltose-substituted maleimide (MalMI) were newly synthesized. RAFT copolymerization of MalVE and ethyl maleimide (EtMI) (monomer feed ratio: MalVE:EtMI = 1:1) afforded periodic glycopolymers (poly(MalVE-co-EtMI)) consisting of major parts of alternating structure (-(MalVE-EtMI)_n-) and a small part of consecutive sequences of EtMI (–EtMI-EtMI-). Occurrence of the latter sequences was caused by the homopolymerizability of maleimide under the present polymerization condition, and the formation of the consecutive sequences of EtMI was successfully suppressed by varying the monomer feed ratio. RAFT copolymerization of LacVE and EtMI was also found to proceed and similarly yielded periodic glycopolymers (poly(LacVE-co-EtMI)). Moreover, RAFT copolymerization of LacVE and MalMI (monomer feed ratio: LacVE:MalMI = 1:1) was performed to give copolymers (poly(LacVE-co-MalMI)) having composition ratio of LacVE/MalMI ≈ 36/64. The resultant periodic glycopolymers poly(MalVE-co-EtMI) and poly(LacVE-co-EtMI) were subjected to lectin binding assay using concanavalin A and peanut agglutinin, exhibiting the glycocluster effect. Moreover, these glycopolymers obtained from the copolymerization of VE and MI were found to be non-cytotoxic. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

18 pages, 2924 KiB

Open AccessArticle

Molecular Mechanism of Xylogenesis in Moso Bamboo (Phyllostachys edulis) Shoots during Cold Storage

by Changtao Li, Lingling Xuan, Yuming He, Jie Wang, Hui Zhang, Yeqing Ying, Aimin Wu, Antony Bacic, Wei Zeng and Lili Song

Polymers 2019, 11(1), 38; https://doi.org/10.3390/polym11010038 - 27 Dec 2018

Cited by 11 | Viewed by 4964

Abstract

A bamboo shoot is the immature stem of the woody grass and a nutritious and popular vegetable in East Asia. However, it undergoes a rapid xylogenesis process right after harvest, even being stored in a cold chamber. To investigate the molecular regulation mechanisms [...] Read more.

A bamboo shoot is the immature stem of the woody grass and a nutritious and popular vegetable in East Asia. However, it undergoes a rapid xylogenesis process right after harvest, even being stored in a cold chamber. To investigate the molecular regulation mechanisms of xylogenesis in Moso bamboo (Phyllostachys edulis) shoots (MBSes) during cold storage, the measurement of cell wall polymers (cellulose, hemicellulose, and lignin) and related enzyme activities (phenylalanine ammonia lyase (PAL), cinnamyl alcohol dehydrogenase (CAD), peroxidase (POD), and xylan xylosyltransferase (XylT)) and transcriptomic analysis were performed during cold storage. It was noticed that cellulose and lignin contents increased, while hemicellulose content exhibited a downward trend. PAL, CAD, and POD activity presented an upward trend generally in MBS when stored at 4 °C for 16 days. XylT activity showed a descending trend during the stages of storage, but slightly increased during the 8th to 12th days after harvest at 4 °C. Transcriptomic analysis identified 72, 28, 44, and 31 functional unigenes encoding lignin, cellulose, xylan biosynthesis enzymes, and transcription factors (TFs), respectively. Many of these secondary cell wall (SCW)-related genes showed higher expression levels in the later period of cold storage. Quantitative RT-PCR analysis of the selected genes conformed to the expression pattern. Our study provides a comprehensive analysis of MBS secondary wall biosynthesis at the molecular level during the cold storage process. The results give insight into the xylogenesis process of this economically important vegetable and shed light on solving this problem of the post-harvest industry. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

13 pages, 2485 KiB

Open AccessArticle

Dynamic High-Pressure Microfluidization-Treated Pectin under Different Ethanol Concentrations

by Cheng-Mei Liu, Lu Liang, Xi-Xiang Shuai, Rui-Hong Liang and Jun Chen

Polymers 2018, 10(12), 1410; https://doi.org/10.3390/polym10121410 - 19 Dec 2018

Cited by 17 | Viewed by 4795

Abstract

We previously reported that dynamic high-pressure microfluidization (DHPM) can degrade pectin in aqueous solution. In this study, we further investigated the effect of DHPM on pectin in water-ethanol systems. In the absence of DHPM treatment, it was found that pectin exhibited increased average [...] Read more.

We previously reported that dynamic high-pressure microfluidization (DHPM) can degrade pectin in aqueous solution. In this study, we further investigated the effect of DHPM on pectin in water-ethanol systems. In the absence of DHPM treatment, it was found that pectin exhibited increased average particle size and unchanged average molecular weight, but a decline in reducing-sugar-ends content with the increase of ethanol concentrations (0–10% v/v). These results indicated that the addition of ethanol induced aggregation of pectin. During DHPM treatment, pectin underwent disaggregation and degradation under all measured ethanol concentrations. Disaggregation was enhanced but degradation was weakened with the increase of ethanol concentration. FT-IR and UV spectra indicated that demethylation but no β-elimination occurred in the water-ethanol system during DHPM. Finally, the mechanism of DHPM-induced disaggregation and degradation of pectin under a water-ethanol system was updated. This work may help us to find a suitable condition for reducing the degradation of pectin during the process of homogenization. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

9 pages, 22801 KiB

Open AccessArticle

Difference in Macroscopic Morphologies of Amylosic Supramolecular Networks Depending on Guest Polymers in Vine-Twining Polymerization

by Saya Orio, Takuya Shoji, Kazuya Yamamoto and Jun-ichi Kadokawa

Polymers 2018, 10(11), 1277; https://doi.org/10.3390/polym10111277 - 16 Nov 2018

Cited by 8 | Viewed by 3922

Abstract

Amylose, a natural polysaccharide, acts as a host molecule to form supramolecular inclusion complexes in its enzymatically formation process, that is, phosphorylase-catalyzed enzymatic polymerization using the α-d-glucose 1-phosphate monomer and the maltooligosaccharide primer, in the presence of appropriate guest polymers (vine-twining [...] Read more.

Amylose, a natural polysaccharide, acts as a host molecule to form supramolecular inclusion complexes in its enzymatically formation process, that is, phosphorylase-catalyzed enzymatic polymerization using the α-d-glucose 1-phosphate monomer and the maltooligosaccharide primer, in the presence of appropriate guest polymers (vine-twining polymerization). Furthermore, in the vine-twining polymerization using maltooligosaccharide primer-grafted polymers, such as maltoheptaose (G₇)-grafted poly(γ-glutamic acid) (PGA), in the presence of poly(ε-caprolactone) (PCL), the enzymatically elongated amylose graft chains have formed inclusion complexes with PCL among the PGA main-chains to construct supramolecular networks. Either hydrogelation or aggregation as a macroscopic morphology from the products was observed in accordance with PCL/primer feed ratios. In this study, we evaluated macroscopic morphologies from such amylosic supramolecular networks with different guest polymers in the vine-twining polymerization using G₇-grafted PGA in the presence of polytetrahydrofuran (PTHF), PCL, and poly(l-lactide) (PLLA). Consequently, we found that the reaction mixture using PTHF totally turned into a hydrogel form, whereas the products using PCL and PLLA were aggregated in the reaction mixtures. The produced networks were characterized by powder X-ray diffraction and scanning electron microscopic measurements. The difference in the macroscopic morphologies was reasonably explained by stabilities of the complexes depending on the guest polymers. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Figure 1

18 pages, 3859 KiB

Open AccessArticle

Therapeutic Effect and Metabolic Mechanism of A Selenium-Polysaccharide from Ziyang Green Tea on Chronic Fatigue Syndrome

by Changzhuan Shao, Jing Song, Shanguang Zhao, Hongke Jiang, Baoping Wang and Aiping Chi

Polymers 2018, 10(11), 1269; https://doi.org/10.3390/polym10111269 - 15 Nov 2018

Cited by 18 | Viewed by 4810

Abstract

Ziyang green tea was considered a medicine food homology plant to improve chronic fatigue Ssyndrome (CFS) in China. The aim of this research was to study the therapeutic effect of selenium-polysaccharides (Se-TP) from Ziyang green tea on CFS and explore its metabolic mechanism. [...] Read more.

Ziyang green tea was considered a medicine food homology plant to improve chronic fatigue Ssyndrome (CFS) in China. The aim of this research was to study the therapeutic effect of selenium-polysaccharides (Se-TP) from Ziyang green tea on CFS and explore its metabolic mechanism. A CFS-rats model was established in the present research and Se-TP was administrated to evaluate the therapeutic effect on CFS. Some serum metabolites including blood urea nitrogen (BUN), blood lactate acid (BLA), corticosterone (CORT), and aldosterone (ALD) were checked. Urine metabolites were analyzed via gas chromatography-mass spectrometry (GC-MS). Multivariate statistical analysis was also used to check the data. The results selected biomarkers that were entered into the MetPA database to analyze their corresponding metabolic pathways. The results demonstrated that Se-TP markedly improved the level of BUN and CORT in CFS rats. A total of eight differential metabolites were detected in GC-MS analysis, which were benzoic acid, itaconic acid, glutaric acid, 4-acetamidobutyric acid, creatine, 2-hydroxy-3-isopropylbutanedioic acid, l-dopa, and 21-hydroxypregnenolone. These differential metabolites were entered into the MetPA database to search for the corresponding metabolic pathways and three related metabolic pathways were screened out. The first pathway was steroid hormone biosynthesis. The second was tyrosine metabolism, and the third was arginine-proline metabolism. The 21-hydroxypregnenolone level of rats in the CFS group markedly increased after the Se-TP administration. In conclusion, Se-TP treatments on CFS rats improved their condition. Its metabolic mechanism was closely related to that which regulates the steroid hormone biosynthesis. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

15 pages, 3325 KiB

Open AccessArticle

Effects of Achyranthes bidentata Polysaccharides on Intestinal Morphology, Immune Response, and Gut Microbiome in Yellow Broiler Chickens Challenged with Escherichia coli K88

by Zhuying Liu, Xiaolong Wang, Shuqi Ou, Muhammed Adebayo Arowolo, De-Xing Hou and Jianhua He

Polymers 2018, 10(11), 1233; https://doi.org/10.3390/polym10111233 - 7 Nov 2018

Cited by 40 | Viewed by 5981

Abstract

The present study was conducted to investigate the effects of dietary Achyranthes bidentata polysaccharide (ABPS) supplementation on performance, immune response, intestinal mucosal morphology, and gut microbiome in yellow-feathered broilers challenged with Escherichia coli K88. A 2 × 2 factorial design was used for [...] Read more.

The present study was conducted to investigate the effects of dietary Achyranthes bidentata polysaccharide (ABPS) supplementation on performance, immune response, intestinal mucosal morphology, and gut microbiome in yellow-feathered broilers challenged with Escherichia coli K88. A 2 × 2 factorial design was used for the trial. Two hundred and forty one-day-old female broilers were randomly assigned to four treatments: (1) negative-control broilers were fed by a basal diet and saline (NG); (2) positive-control broilers were fed by a basal diet and orally challenged with 10⁸ CFU E. coli K88 (CNG); (3) ABP group broilers were fed by a basal diet containing ABPS (500 mg/kg of feed) and saline; (4) CABP group broilers were fed by a basal diet containing ABPS (500 mg/kg of feed) and orally challenged with 10⁸ CFU E. coli K88. Growth performance, serum biochemical indexes, immune responses, intestinal mucosal morphology, and cecal microbial community structure were evaluated. The ABP group had greatest body weight (BW), average daily body weight gain (ADG), and intestinal villus height compared to other treatments (p < 0.05). The CABP group had a higher villus height/crypt depth ratio (V/C) compared with other treatments (p < 0.05). The expression levels of NF-κB were lower in the ABP group. The CNG group had higher Escherichia coli and Enterococcus contents in cecal samples compared to other treatments (p < 0.05). Serum glucose, uric acid, TNF-α, and Secretory Immunoglobulin A (S-IgA) levels were higher in broilers challenged with E. coli (p < 0.001) than that with saline. Broilers challenged with E. coli had reduced taxa richness in the cecal samples. Sequencing of 16S rRNA genes in cecal samples revealed that a lower proportion of Firmicutes and a higher proportion of Proteobacteria were detected in the broilers challenged with E. coli. Compared with the controls, dietary ABPS supplementation increased serum total protein, albumin, and S-IgA levels, but decreased serum glucose, uric acid, and TNF-α levels in broilers (p < 0.05). Diet supplemented with ABPS increased the Firmicutes/Bacteroidetes ratio and the abundance of Ruminococcaceae and Lachnospiraceae, and altered cecal microbiota community structure. These results suggest that ABPS can promote growth performance and improve intestinal morphology and microbiota community structure in broilers challenged with E. coli K88. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

13 pages, 2488 KiB

Open AccessArticle

Effects of Calcium Alginate Submicroparticles on Seed Germination and Seedling Growth of Wheat (Triticum aestivum L.)

by Jinxia He, Ruixin Li, Xue Sun, Wenxia Wang, Jianen Hu, Hongguo Xie and Heng Yin

Polymers 2018, 10(10), 1154; https://doi.org/10.3390/polym10101154 - 16 Oct 2018

Cited by 16 | Viewed by 4336

Abstract

Calcium alginate (CaAlg) submicroparticles have a potential application in agricultural delivery systems. This study investigated the effects of CaAlg submicroparticles on seed germination and seedling growth of wheat. CaAlg submicroparticles with a Z-average diameter of around 250.4 nm and a measured zeta potential [...] Read more.

Calcium alginate (CaAlg) submicroparticles have a potential application in agricultural delivery systems. This study investigated the effects of CaAlg submicroparticles on seed germination and seedling growth of wheat. CaAlg submicroparticles with a Z-average diameter of around 250.4 nm and a measured zeta potential value of about −25.4 mV were prepared and characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDS). After this, the effects of the concentration of CaAlg submicroparticles (10–500 μg/mL) on germination percentage, seedling length, the number of adventitious roots, chlorophyll content and soluble protein content were evaluated. The results demonstrated a significant increase in the level of germination percentage (9.0%), seedling index (50.3%), adventitious roots (27.5%), seedling length (17.0%), chlorophyll (8.7%) and soluble protein contents (4.5%) at a concentration of 100 μg/mL. However, an inhibitory effect was observed at a concentration of 500 μg/mL. The SEM examination showed that CaAlg submicroparticles could be successfully adsorbed onto the surface of the wheat seed. Further studies proved that CaAlg submicroparticles at a concentration of 100 μg/mL promoted the expression of indole-3-acetic acid (IAA)-related genes (YUCCA9, AUX1, ARF and UGT) in wheat, which resulted in an increase of 69% and 21% in IAA concentration in wheat roots and shoots, respectively. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Figure 1

10 pages, 1699 KiB

Open AccessArticle

Structural Properties and Macrophage Activation of Cell Wall Polysaccharides from the Fruiting Bodies of Hericium erinaceus

by Di Wu, Shan Yang, Chuan Tang, Yanfang Liu, Qiaozhen Li, Henan Zhang, Fengjie Cui and Yan Yang

Polymers 2018, 10(8), 850; https://doi.org/10.3390/polym10080850 - 1 Aug 2018

Cited by 5 | Viewed by 10539

Abstract

In this study, water-soluble and alkali-soluble cell wall polysaccharides were obtained from fruiting body extracted residual micropowders of Hericium erinaceus, harvested at seven different growing stages. The structural properties and in vitro immunity activities of cell wall polysaccharides extracted successively by hot [...] Read more.

In this study, water-soluble and alkali-soluble cell wall polysaccharides were obtained from fruiting body extracted residual micropowders of Hericium erinaceus, harvested at seven different growing stages. The structural properties and in vitro immunity activities of cell wall polysaccharides extracted successively by hot water and sodium hydroxide solution were studied, and the results indicated that the yield and content of polysaccharides increased during the reproductive growth stage and decreased with the maturity of the fruiting body. Water-soluble cell wall polysaccharides mainly composed of glucose and galactose at a molar ratio of 3.4–14:1.0, and also contained a small ratio of glucuronic acid. The alkali-soluble cell wall polysaccharides were glucans with lower molecular weight and higher macrophage activation activity in vitro than water-soluble ones. Our findings suggest that the growth stages (H4 and H5) are suitable for harvesting H. erinaceus fruiting bodies with higher cell wall polysaccharide yield and functional benefits. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

13 pages, 2482 KiB

Open AccessArticle

Wound Dressings Based on Chitosan-Dialdehyde Cellulose Nanocrystals-Silver Nanoparticles: Mechanical Strength, Antibacterial Activity and Cytotoxicity

by Feng Dong and Shujun Li

Polymers 2018, 10(6), 673; https://doi.org/10.3390/polym10060673 - 16 Jun 2018

Cited by 50 | Viewed by 6546

Abstract

The present work envisages a simple approach to synthesize a new wound dressing based on chitosan-dialdehyde cellulose nanocrystal-silver nanoparticles (CS-DCNC-AgNPs). Silver nanoparticles (AgNPs) were generated in-situ by periodate oxidation of cellulose nanocrystals to generate aldehyde functions, which were used to reduce Ag⁺ [...] Read more.

The present work envisages a simple approach to synthesize a new wound dressing based on chitosan-dialdehyde cellulose nanocrystal-silver nanoparticles (CS-DCNC-AgNPs). Silver nanoparticles (AgNPs) were generated in-situ by periodate oxidation of cellulose nanocrystals to generate aldehyde functions, which were used to reduce Ag⁺ into Ag⁰ in mild alkaline conditions. Subsequently, the dialdehyde cellulose nanocrystal-silver nanoparticles (DCNC-AgNPs) were added to chitosan (CS) to form the wound dressings by solution casting method. The aim was to enhance the antibacterial effect of CS by incorporation of AgNPs and to improve the mechanical strength and hydrophobicity of CS by incorporation of DCNC that cross-linked by hydrogen bonds. The antibacterial activities were evaluated against five gram-negative bacteria, one gram-positive bacteria, and three fungi. The in vitro cytotoxicity assay was performed using the NIH3T3 cell lines by Sulforhodamine B assay. Research outputs signified that CS-DCNC-AgNPs possessed good mechanical strength and hydrophobicity, high antibacterial activity and less cytotoxicity. Our results propose that CS-DCNC-AgNPs can be a promising, safe antibacterial to be incorporated in wound dressings. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

16 pages, 7212 KiB

Open AccessArticle

Preparation and Characterization of Superabsorbent Polymers Based on Starch Aldehydes and Carboxymethyl Cellulose

by Jungmin Lee, Soohee Park, Hyun-gyoo Roh, Seungtaek Oh, Sunghoon Kim, Myounguk Kim, Donghyun Kim and Jongshin Park

Polymers 2018, 10(6), 605; https://doi.org/10.3390/polym10060605 - 2 Jun 2018

Cited by 52 | Viewed by 10991

Abstract

Superabsorbent polymers (SAPs) are crosslinked hydrophilic polymers that are capable of absorbing large amounts of water. Commercial SAPs are mostly produced with acrylic acid that cannot be easily biodegraded. Therefore, in this study, polysaccharide-based SAPs using carboxymethyl cellulose as a major component were [...] Read more.

Superabsorbent polymers (SAPs) are crosslinked hydrophilic polymers that are capable of absorbing large amounts of water. Commercial SAPs are mostly produced with acrylic acid that cannot be easily biodegraded. Therefore, in this study, polysaccharide-based SAPs using carboxymethyl cellulose as a major component were prepared. Starch aldehydes and citric acid were selected due to their environment-friendly, non-toxic, and biodegradable properties compared to conventional crosslinking agents. Starch aldehydes were prepared by periodate oxidation, which forms aldehyde groups by taking the places of C–OH groups at C-2 and C-3. Furthermore, starch aldehydes were analyzed through the change in FT-IR spectra, the aldehyde quantitation, and the morphology in FE-SEM images. In the crosslinking of polysaccharide-based SAPs, the acetal bridges from starch aldehydes led to a large amount of water entering the network structure of the SAPs. However, the ester bridges from citric acid interfered with the water penetration. In addition, the swelling behavior of the SAPs was analyzed by the Fickian diffusion model and the Schott’s pseudo second order kinetics model. The relationship between swelling behavior and morphology of the SAPs was analyzed by FE-SEM images. In conclusion, polysaccharide-based SAPs were well prepared and the highest equilibrium swelling ratio was 87.0 g/g. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

11 pages, 2547 KiB

Open AccessArticle

Lipid-Lowering Effect of the Pleurotus eryngii (King Oyster Mushroom) Polysaccharide from Solid-State Fermentation on Both Macrophage-Derived Foam Cells and Zebrafish Models

by Hua Wei, Shang Yue, Shizhu Zhang and Ling Lu

Polymers 2018, 10(5), 492; https://doi.org/10.3390/polym10050492 - 3 May 2018

Cited by 26 | Viewed by 5637

Abstract

Hyperlipidemia is a key risk factor in inducing fatty liver, hypertension, atherosclerosis and cerebrovascular diseases. Previous studies have verified that polysaccharides from fruiting bodies (PEPE) of Pleurotus eryngii (king oyster mushroom) are capable of decreasing the lipid content. In this study, the P. [...] Read more.

Hyperlipidemia is a key risk factor in inducing fatty liver, hypertension, atherosclerosis and cerebrovascular diseases. Previous studies have verified that polysaccharides from fruiting bodies (PEPE) of Pleurotus eryngii (king oyster mushroom) are capable of decreasing the lipid content. In this study, the P. eryngii polysaccharide is obtained by solid-state fermentation (PESF) using lignocellulosic wastes, corn-cobs and wheat bran. The high-performance liquid chromatography (HPLC) assays indicate that PESF has a similar composition to that of PEPE. Meanwhile, PESF has no detectable toxicity and is able to significantly inhibit foam-cell formation in murine macrophage cells (RAW264.7) induced by oxidized low-density lipoprotein. Further verification indicates that PESF has lipid-lowering effects during the lipid absorption phase in a zebrafish hyperlipidemia model. Our findings suggest that the P. eryngii polysaccharide from solid-state fermentation (PESF) can be used as a valuable lipid-lowering food additive or raw materials for producing lipid-lowering drugs. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

10 pages, 20156 KiB

Open AccessArticle

Study on the Use of Microbial Cellulose as a Biocarrier for 1,3-Dihydroxy-2-Propanone and Its Potential Application in Industry

by Lidia Stasiak-Różańska and Justyna Płoska

Polymers 2018, 10(4), 438; https://doi.org/10.3390/polym10040438 - 14 Apr 2018

Cited by 29 | Viewed by 6830

Abstract

Can microbial cellulose (MC) be used as a bio-carrier for 1,3-dihydroxy-2-propanone (DHA)? The aim of this study was to examine the possibility of using MC as a biomaterial for DHA transferring into the stratum corneum and inducing changes in skin color. The MC [...] Read more.

Can microbial cellulose (MC) be used as a bio-carrier for 1,3-dihydroxy-2-propanone (DHA)? The aim of this study was to examine the possibility of using MC as a biomaterial for DHA transferring into the stratum corneum and inducing changes in skin color. The MC patches were obtained from Gluconacetobacter xylinus strain and incubated in solutions with various concentrations of DHA (g·L⁻¹: 20; 50; 80; 110) at 22 °C for 24 h. Afterwards; the patches were applied onto the skin for 15, 30, or 60 min. Skin color changes were assessed visually compared to a control patches without DHA. The intensity of skin color was increasing with the increase of DHA concentration and time of patches application. Application of MC patches with DHA (50 g·L⁻¹) for 30 min ensured the color which was considered the closest to the desired natural tan effect. MC patches containing DHA can be biocarriers enabling DHA transport into the stratum corneum and causing skin color changes. Study results indicate a new possibility for industrial applications of MC; e.g., as a biocarrier in masking the symptoms of vitiligo or production of self-tanning agents in the form of masks. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

11 pages, 2801 KiB

Open AccessArticle

Fluorescent Labeling of Polysaccharides from Masson Pine Pollen and Its Effect on RAW264.7 Macrophages

by Mengmeng Sun, Fangchen Su, Jinxin Yang, Zheng Gao and Yue Geng

Polymers 2018, 10(4), 372; https://doi.org/10.3390/polym10040372 - 26 Mar 2018

Cited by 19 | Viewed by 8022

Abstract

In order to explore the immediate effect of polysaccharides and macrophages, polysaccharides from masson pine pollen (PPM60) were labeled with fluorescein isothiocyanate (FITC) by using a chemical-derived method, and the reactant was named PPM60-Tyr-FITC. Direct interaction of PPM60-Tyr-FITC and RAW264.7 macrophages could be [...] Read more.

In order to explore the immediate effect of polysaccharides and macrophages, polysaccharides from masson pine pollen (PPM60) were labeled with fluorescein isothiocyanate (FITC) by using a chemical-derived method, and the reactant was named PPM60-Tyr-FITC. Direct interaction of PPM60-Tyr-FITC and RAW264.7 macrophages could be detected by flow cytometer (FCM), and this interaction could be inhibited by Pitstop 2 (clathrin inhibitor) and TAK-242 (Toll-like receptor 4 inhibitor). The results of confocal laser scanning microscopy (CLSM) also revealed that there was a co-localization phenomenon between PPM60-Tyr-FITC and RAW264.7 macrophage receptors, and it could be suppressed by Pitstop 2 and TAK-242. It was confirmed that PPM60 enters into RAW264.7 macrophages mainly through endocytosis, rather than the phagocytosis, and TLR4 played a mediating role. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

18 pages, 4042 KiB

Open AccessArticle

Extraction Optimization, Purification, Antioxidant Activity, and Preliminary Structural Characterization of Crude Polysaccharide from an Arctic Chlorella sp.

by Hong Song, Meilin He, Chuankun Gu, Dong Wei, Yuqi Liang, Junmei Yan and Changhai Wang

Polymers 2018, 10(3), 292; https://doi.org/10.3390/polym10030292 - 9 Mar 2018

Cited by 71 | Viewed by 8750

Abstract

The arctic strain of Chlorella sp. (Chlorella-Arc) exists in the coldest and driest arctic ecosystems, and it is a new resource of active polysaccharides. The extraction of crude polysaccharide from Chlorella-Arc was optimized using the response surface methodology. A crude [...] Read more.

The arctic strain of Chlorella sp. (Chlorella-Arc) exists in the coldest and driest arctic ecosystems, and it is a new resource of active polysaccharides. The extraction of crude polysaccharide from Chlorella-Arc was optimized using the response surface methodology. A crude polysaccharide yield of approximately 9.62 ± 0.11% dry weight was obtained under these optimized conditions. Three fractions (P-I, P-II, and P-III) were present after purification by 2-diethylaminoethanol Sepharose Fast Flow and Sephadex G-100 chromatography. The P-IIa fraction demonstrated significant antioxidant activities. Moreover, P-IIa was an α- and β-type heteropolysaccharide with a pyran group and contained variable amounts of rhamnose, arabinose, glucose, and galactose based on fourier-transform infrared spectroscopy, high-performance liquid chromatography, and ¹H and ¹³C nuclear magnetic resonance imaging. Production of high amounts of polysaccharide may allow further exploration of the microalgae Chlorella-Arc as a natural antioxidant. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Figure 1

14 pages, 1688 KiB

Open AccessArticle

Exopolysaccharide Gellan Gum and Derived Oligo-Gellan Enhance Growth and Antimicrobial Activity in Eucomis Plants

by Piotr Salachna, Małgorzata Mizielińska and Marcin Soból

Polymers 2018, 10(3), 242; https://doi.org/10.3390/polym10030242 - 27 Feb 2018

Cited by 41 | Viewed by 6356

Abstract

One of the visible trends in the cultivation of plants, particularly of medicinal ones, is the increasing interest of researchers in polysaccharides and their derivatives that show biostimulatory properties and are also safe to use. In the current study, we evaluated the effects [...] Read more.

One of the visible trends in the cultivation of plants, particularly of medicinal ones, is the increasing interest of researchers in polysaccharides and their derivatives that show biostimulatory properties and are also safe to use. In the current study, we evaluated the effects of gellan gum and its depolymerized form oligo-gellan, on growth and antimicrobial activity of two ornamental species Eucomis bicolor and Eucomis comosa used in natural medicine. The biopolymers were applied in the form of bulb coating prepared by using polyelectrolyte complexes. In both species investigated, gellan gum and oligo-gellan enhanced the fresh weight of leaves and bulbs, the performance of the photosynthetic apparatus, and the leaf content of basic macronutrients. In comparison with the control, the plants treated with oligo-gellan accumulated more biomass, were first to flower, and had the highest leaf content of potassium. The extracts from the bulbs treated with gellan gum and oligo-gellan showed higher effectiveness in reducing the count of Bacillus atrophaeus, Escherichia coli, and Staphylococcus aureus than those from the bulbs not treated with the polysaccharides. The research described here largely expands our current knowledge on the effects of gellan gum derivatives and has a huge practical potential in agriculture production. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

12 pages, 4483 KiB

Open AccessArticle

Enhanced Solubilization of Fluoranthene by Hydroxypropyl β-Cyclodextrin Oligomer for Bioremediation

by Kyeong Hui Park, Jae Min Choi, Eunae Cho and Seunho Jung

Polymers 2018, 10(2), 111; https://doi.org/10.3390/polym10020111 - 24 Jan 2018

Cited by 10 | Viewed by 5735

Abstract

Fluoranthene (FT) is a polycyclic aromatic hydrocarbon (PAH), consisting of naphthalene and benzene rings connected by a five-member ring. It is widespread in the environment. The hydrophobicity of FT limits its availability for biological uptake and degradation. In this study, hydroxypropyl β-cyclodextrin oligomers [...] Read more.

Fluoranthene (FT) is a polycyclic aromatic hydrocarbon (PAH), consisting of naphthalene and benzene rings connected by a five-member ring. It is widespread in the environment. The hydrophobicity of FT limits its availability for biological uptake and degradation. In this study, hydroxypropyl β-cyclodextrin oligomers (HP-β-CD-ol) were synthesized with epichlorohydrin (EP), while the solubility enhancement of FT by HP-β-CD-ol was investigated in water. The synthesized HP-β-CD-ol was characterized by MALDI-TOF mass spectrometry (MS), ¹H NMR, and ¹³C NMR spectroscopy. The solubility of FT increased 178-fold due to the complex formation with HP-β-CD oligomers. The inclusion complexes of FT/HP-β-CD-ol were analyzed using Fourier-Transform Infrared (FT-IR), Differential Scanning Calorimetry (DSC), Scanning Electron Microscope (SEM), and Nuclear Overhauser Effect Spectroscopy Nuclear magnetic resonance (NOESY NMR) spectroscopy. On the basis of these results, HP-β-CD-ol is recommended as a potential solubilizer for the development of PAH removal systems. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

1537 KiB

Open AccessArticle

Microencapsulation of Lactobacillus Acidophilus by Xanthan-Chitosan and Its Stability in Yoghurt

by Guowei Shu, Yunxia He, Li Chen, Yajuan Song, Jiangpeng Meng and He Chen

Polymers 2017, 9(12), 733; https://doi.org/10.3390/polym9120733 - 20 Dec 2017

Cited by 18 | Viewed by 6474

Abstract

Microencapsulations of Lactobacillus acidophilus in xanthan-chitosan (XC) and xanthan-chitosan-xanthan (XCX) polyelectrolyte complex (PEC) gels were prepared in this study. The process of encapsulation was optimized with the aid of response surface methodology (RSM). The optimum condition was chitosan of 0.68%, xanthan of 0.76%, [...] Read more.

Microencapsulations of Lactobacillus acidophilus in xanthan-chitosan (XC) and xanthan-chitosan-xanthan (XCX) polyelectrolyte complex (PEC) gels were prepared in this study. The process of encapsulation was optimized with the aid of response surface methodology (RSM). The optimum condition was chitosan of 0.68%, xanthan of 0.76%, xanthan-L. acidophilus mixture (XLM)/chitosan of 1:2.56 corresponding to a high viable count (1.31 ± 0.14) × 10¹⁰ CFU·g⁻¹, and encapsulation yield 86 ± 0.99%, respectively. Additionally, the application of a new encapsulation system (XC and XCX) in yoghurt achieved great success in bacterial survival during the storage of 21 d at 4 °C and 25 °C, respectively. Specially, pH and acidity in yogurt were significantly influenced by the new encapsulation system in comparison to free suspension during 21 d storage. Our study provided a potential encapsulation system for probiotic application in dairy product which paving a new way for functional food development. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

18551 KiB

Open AccessArticle

Extraction and Characterization of Cellulose Nanocrystals from Tea Leaf Waste Fibers

by Nur Hayati Abdul Rahman, Buong Woei Chieng, Nor Azowa Ibrahim and Norizah Abdul Rahman

Polymers 2017, 9(11), 588; https://doi.org/10.3390/polym9110588 - 7 Nov 2017

Cited by 104 | Viewed by 12095

Abstract

The aim was to explore the utilization of tea leaf waste fibers (TLWF) as a source for the production of cellulose nanocrystals (CNC). TLWF was first treated with alkaline, followed by bleaching before being hydrolyzed with concentrated sulfuric acid. The materials attained after [...] Read more.

The aim was to explore the utilization of tea leaf waste fibers (TLWF) as a source for the production of cellulose nanocrystals (CNC). TLWF was first treated with alkaline, followed by bleaching before being hydrolyzed with concentrated sulfuric acid. The materials attained after each step of chemical treatments were characterized and their chemical compositions were studied. The structure analysis was examined by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). From FTIR analysis, two peaks at 1716 and 1207 cm⁻¹—which represent C=O stretchingand C–O stretching, respectively—disappeared in the spectra after the alkaline and bleaching treatments indicated that hemicellulose and lignin were almost entirely discarded from the fiber. The surface morphology of TLWF before and after chemical treatments was investigated by scanning electron microscopy (SEM) while the dimension of CNC was determined by transmission electron microscopy (TEM). The extraction of CNC increased the surface roughness and the crystallinity index of fiber from 41.5% to 83.1%. Morphological characterization from TEM revealed the appearance of needle-like shaped CNCs with average diameter of 7.97 nm. The promising results from all the analyses justify TLWF as a principal source of natural materials which can produce CNC. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

1325 KiB

Open AccessArticle

A Concise Synthesis of Three Branches Derived from Polysaccharide RN1 and Anti-Pancreatic Cancer Activity Study

by Deqin Cai, Yanli Yao, Yubo Tang, Zheng Wang, Wei Shi, Wei Huang and Kan Ding

Polymers 2017, 9(10), 536; https://doi.org/10.3390/polym9100536 - 21 Oct 2017

Cited by 5 | Viewed by 5333

Abstract

RN1, a polysaccharide from flowers of Panax pseudo-ginsieng Wall. Var. notoginseng (Burkill) Hoo & Tseng, is a potential multi-targeting drug candidate for pancreatic cancer treatment. However, the active targeting domain of RN1 is still unknown. Herein, three RN1 derived branches were synthesized via [...] Read more.

RN1, a polysaccharide from flowers of Panax pseudo-ginsieng Wall. Var. notoginseng (Burkill) Hoo & Tseng, is a potential multi-targeting drug candidate for pancreatic cancer treatment. However, the active targeting domain of RN1 is still unknown. Herein, three RN1 derived branches were synthesized via [3+2] or [2+2] strategies, efficiently. Two pentasaccharides, 18 and 27, showed similar inhibition effect on pancreatic cancer BxPC-3 cells to that of RN1 at same concentration. Interestingly, tetrasaccharide 21 potently inhibited gemcitabineresistant cell line Panc-1 at high concentration. These suggest that the branches of RN1 might be the active targeting domain and tetrasaccharide 21 might be a potential leading compound for pancreatic cancer with gemcitabine resistance. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

3526 KiB

Open AccessArticle

Isolation and Characterization of Cellulose from Different Fruit and Vegetable Pomaces

by Monika Szymańska-Chargot, Monika Chylińska, Karolina Gdula, Arkadiusz Kozioł and Artur Zdunek

Polymers 2017, 9(10), 495; https://doi.org/10.3390/polym9100495 - 9 Oct 2017

Cited by 223 | Viewed by 18340

Abstract

A new fractionation process was developed to achieve valorization of fruit and vegetable pomaces. The importance of the residues from fruits and vegetables is still growing; therefore; the study presents the novel route of a fractioning process for the conversion of agro-industrial biomasses, [...] Read more.

A new fractionation process was developed to achieve valorization of fruit and vegetable pomaces. The importance of the residues from fruits and vegetables is still growing; therefore; the study presents the novel route of a fractioning process for the conversion of agro-industrial biomasses, such as pomaces, into useful feedstocks with potential application in the fields of fuels, chemicals, and polymers. Hence, the biorefinery process is expected to convert them into various by-products offering a great diversity of low-cost materials. The final product of the process is the cellulose of the biofuel importance. The study presents the novel route of the fractioning process for the conversion of agro-industrial biomasses, such as pomaces, into useful feedstocks with a potential application in the fields of fuels, chemicals, and polymers. Therefore the aim of this paper was to present the novel route of the pomaces fraction and the characterization of residuals. Pomaces from apple, cucumber, carrot, and tomato were treated sequentially with water, acidic solution, alkali solution, and oxidative reagent in order to obtain fractions reach in sugars, pectic polysaccharides, hemicellulose, cellulose, and lignin. Pomaces were characterized by dry matter content, neutral detergent solubles, hemicellulose, cellulose, and lignin. Obtained fractions were characterized by the content of pectins expressed as galacturonic acid equivalent and hemicelluloses expressed as a xyloglucan equivalent. The last fraction and residue was cellulose characterized by crystallinity degree by X-ray diffractometer (XRD), microfibril diameter by atomic force microscope (AFM), and overall morphology by scanning electron microscope (SEM). The hemicelluloses content was similar in all pomaces. Moreover, all the materials were characterized by the high pectins level in extracts evaluated as galacturonic acid content. The lignins content compared with other plant biomasses was on a very low level. The cellulose fraction was the highest in cucumber pomace. The cellulose fraction was characterized by crystallinity degree, microfibril diameter, and overall morphology. Isolated cellulose had a very fine structure with relatively high crystalline index but small crystallites. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

Review

Jump to: Research

9 pages, 1994 KiB

Open AccessReview

Xylans of Red and Green Algae: What Is Known about Their Structures and How They Are Synthesised?

by Yves S.Y. Hsieh and Philip J. Harris

Polymers 2019, 11(2), 354; https://doi.org/10.3390/polym11020354 - 18 Feb 2019

Cited by 55 | Viewed by 6159

Abstract

Xylans with a variety of structures have been characterised in green algae, including chlorophytes (Chlorophyta) and charophytes (in the Streptophyta), and red algae (Rhodophyta). Substituted 1,4-β-d-xylans, similar to those in land plants (embryophytes), occur in the cell wall matrix of advanced [...] Read more.

Xylans with a variety of structures have been characterised in green algae, including chlorophytes (Chlorophyta) and charophytes (in the Streptophyta), and red algae (Rhodophyta). Substituted 1,4-β-d-xylans, similar to those in land plants (embryophytes), occur in the cell wall matrix of advanced orders of charophyte green algae. Small proportions of 1,4-β-d-xylans have also been found in the cell walls of some chlorophyte green algae and red algae but have not been well characterised. 1,3-β-d-Xylans occur as triple helices in microfibrils in the cell walls of chlorophyte algae in the order Bryopsidales and of red algae in the order Bangiales. 1,3;1,4-β-d-Xylans occur in the cell wall matrix of red algae in the orders Palmariales and Nemaliales. In the angiosperm Arabidopsis thaliana, the gene IRX10 encodes a xylan 1,4-β-d-xylosyltranferase (xylan synthase), and, when heterologously expressed, this protein catalysed the production of the backbone of 1,4-β-d-xylans. An orthologous gene from the charophyte green alga Klebsormidium flaccidum, when heterologously expressed, produced a similar protein that was also able to catalyse the production of the backbone of 1,4-β-d-xylans. Indeed, it is considered that land plant xylans evolved from xylans in ancestral charophyte green algae. However, nothing is known about the biosynthesis of the different xylans found in chlorophyte green algae and red algae. There is, thus, an urgent need to identify the genes and enzymes involved. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Figure 1

23 pages, 3429 KiB

Open AccessReview

Polysaccharide Based Scaffolds for Soft Tissue Engineering Applications

by Sanjay Tiwari, Rahul Patil and Pratap Bahadur

Polymers 2019, 11(1), 1; https://doi.org/10.3390/polym11010001 - 20 Dec 2018

Cited by 113 | Viewed by 9164

Abstract

Soft tissue reconstructs require materials that form three-dimensional (3-D) structures supportive to cell proliferation and regenerative processes. Polysaccharides, due to their hydrophilicity, biocompatibility, biodegradability, abundance, and presence of derivatizable functional groups, are distinctive scaffold materials. Superior mechanical properties, physiological signaling, and tunable tissue [...] Read more.

Soft tissue reconstructs require materials that form three-dimensional (3-D) structures supportive to cell proliferation and regenerative processes. Polysaccharides, due to their hydrophilicity, biocompatibility, biodegradability, abundance, and presence of derivatizable functional groups, are distinctive scaffold materials. Superior mechanical properties, physiological signaling, and tunable tissue response have been achieved through chemical modification of polysaccharides. Moreover, an appropriate formulation strategy enables spatial placement of the scaffold to a targeted site. With the advent of newer technologies, these preparations can be tailor-made for responding to alterations in temperature, pH, or other physiological stimuli. In this review, we discuss the developmental and biological aspects of scaffolds prepared from four polysaccharides, viz. alginic acid (ALG), chitosan (CHI), hyaluronic acid (HA), and dextran (DEX). Clinical studies on these scaffolds are also discussed. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Figure 1

31 pages, 726 KiB

Open AccessReview

Biological Activity and Pharmacological Application of Pectic Polysaccharides: A Review

by Salima T. Minzanova, Vladimir F. Mironov, Daria M. Arkhipova, Anna V. Khabibullina, Lubov G. Mironova, Yulia M. Zakirova and Vasili A. Milyukov

Polymers 2018, 10(12), 1407; https://doi.org/10.3390/polym10121407 - 19 Dec 2018

Cited by 215 | Viewed by 13231

Abstract

Pectin is a polymer with a core of alternating α-1,4-linked d-galacturonic acid and α-1,2-l-rhamnose units, as well as a variety of neutral sugars such as arabinose, galactose, and lesser amounts of other sugars. Currently, native pectins have been compared [...] Read more.

Pectin is a polymer with a core of alternating α-1,4-linked d-galacturonic acid and α-1,2-l-rhamnose units, as well as a variety of neutral sugars such as arabinose, galactose, and lesser amounts of other sugars. Currently, native pectins have been compared to modified ones due to the development of natural medicines and health products. In this review, the results of a study of the bioactivity of pectic polysaccharides, including its various pharmacological applications, such as its immunoregulatory, anti-inflammatory, hypoglycemic, antibacterial, antioxidant and antitumor activities, have been summarized. The potential of pectins to contribute to the enhancement of drug delivery systems has been observed. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

667 KiB

Open AccessReview

Exploiting Microbial Polysaccharides for Biosorption of Trace Elements in Aqueous Environments—Scope for Expansion via Nanomaterial Intervention

by Manikandan Muthu, Hui-Fen Wu, Judy Gopal, Iyyakkannu Sivanesan and Sechul Chun

Polymers 2017, 9(12), 721; https://doi.org/10.3390/polym9120721 - 16 Dec 2017

Cited by 31 | Viewed by 7103

Abstract

With pollution sounding high alarms all around us, there is an immediate necessity for remediation. In most cases, the remediation measures require further remediation—the anti-pollutants themselves cause pollution. In this correspondence, the search deepens towards natural biogenic components that can be used for [...] Read more.

With pollution sounding high alarms all around us, there is an immediate necessity for remediation. In most cases, the remediation measures require further remediation—the anti-pollutants themselves cause pollution. In this correspondence, the search deepens towards natural biogenic components that can be used for bioremediation. Polysaccharide and biosorption have been themes in discussion for quite some time, where a slow decline in the enthusiasm in this area has been observed. This review revisits the importance of using polysaccharide based materials for biosorption. The need for polysaccharide-based nanocomposites, which hold better promise for greater deliverables, is emphasized as a means of rejuvenating the future perspectives in this area of application. Full article

(This article belongs to the Special Issue Polysaccharides)

► Show Figures

Graphical abstract

Journal Menu

Journal Browser

Polysaccharides

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Related Special Issue

Published Papers (29 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI