Activity

Thus, the tensile and compression modulus of the calcium alginate films in the dry and hydrated state increases up to three and six times, respectively, with the addition of 2% w/w CNFs. MER-29 inhibitor In addition, the composites reinforced with the lowest CNFs content have the advantage of possessing more transparency and lower production costs. Hyaluronic acid (HA) is a major glycosaminoglycan, a family of structurally complex, linear, anionic hetero-co-polysaccharides. HA is important in various anatomical structures including the eyes, joints, heart and myriad intricate tissues, and is currently widely used in the therapeutics and cosmetics areas. The synthesis of HA of well-defined and uniform chain lengths is of major interest for the development of safer and more reliable drugs and to gain a better understanding of its structure-activity relationships. However, HA has received less attention from the synthetic carbohydrate community compared with other members of the glycosaminoglycan family. In this review, we examine the remarkable progress that has been made in the chemical and chemoenzymatic synthesis of HA, providing a broad spectrum of options to access HA of well controlled chain lengths. V.Reduced graphene oxide (RGO) has shown tremendous potential as a NIR responsive nanomaterial and has been extensively explored for NIR mediated photothermal therapy and drug delivery. However, the potential of NIR as a stimulus to trigger release of entrapped/complexed DNA from its surface have not been explored. Strong complexation between the loaded cargo and the carrier often leads to no-release or decrease in the release of the therapeutic cargo. Herein, we investigated NIR as a stimulus for inducing DNA release from RGO nanocomposites. A quaternary ammonium modified poly(allylamine hydrochloride) functionalized RGO nanocomposite (RGO-MPAH) was synthesized, which was further tagged with a targeting moiety, folic acid (FA). The structural, optical and chemical properties of the synthesized nanocomposites were characterized which validated successful reduction and functionalization of GO with PAH/MPAH. The nanocomposites were found to be non-toxic and showed excellent DNA binding ability at complexation ratios as low as 31 (w/w). Additionally, the nanocomposites demonstrated NIR responsive release of complexed DNA from their surfaces, with RGO-PAH showing maximum DNA release followed by RGO-MPAH and RGO-MPAH-FA. This study shows the potential of NIR light to act as a stimulus for inducing release of entrapped nucleic acids from the surface of nanocarriers. V.In this study, a new strain suspected to be Aureobasidium pullulans was isolated from trees leaves. The molecular characterization and the resulting phylogenetic tree showed that the isolated strain was A. pullulans. Also, the results of methylation analysis, monosaccharide composition, FTIR, NMR and XRD confirmed that the obtained exo-polysaccharide from the mentioned strain was pullulan. The pullulan production optimization by central composite design (CCD) indicated that the maximum yield obtained under optimum conditions (pH of 6.5, sucrose concentration of 5.5% (w/v) and yeast extract concentration of 0.1% (w/v)) was 51.4 ± 0.50 g/L. The produced pullulan had an average molecular weight (Mw) of 2.07 × 105 g.mol-1 based on gel permeation chromatography results. The decomposition temperature (Td) of the produced pullulan was ~300 °C and also, the resulting pullulan had a Newtonian flow behavior in a wide range of concentrations. In the present study, a polysaccharide fraction (PTP) was isolated and purified from the tubers of Pinellia ternata. We researched its structure and anti-tumor activity, and further studied its molecular mechanism of inducing apoptosis of Hep G2 cells. The results indicated that PTP was an acid heteropolysaccharide and the average molecular weight of PTP identified by HPGPC was 3.06 × 106 Da. Ion chromatography (IC) determined that PTP was mainly composed of AraGalGluManGlcAGalA in a molar ratio of 6.9816.567.252.0414.16. Combined with the results of FT-IR and NMR spectroscopy, it was found that PTP is a pyranose containing α-configuration and β-configuration, mainly consist of β-D-Gal, α-D-Glu, α-D-Ara and β-D-Man. By analyzing the results of MTT, cell cycle, Annexin V-FITC/PI double staining and cell morphology observation, we concluded that PTP induced dose-dependent apoptosis of Hep G2 cells via S phase arrest. In addition, mitochondrial membrane potential detection and Western blot further indicated that PTP was capable of inducing apoptosis in Hep G2 cells through an endogenous mitochondria-mediated apoptotic pathway. Oxidized starch (oxStarch) is a major derivative of starch. In present study, 4-acetamide-TEMPO system was firstly applied to prepare specifically oxidized starch, homogeneous 1,4-linked α-D-glucuronan. The impact of oxidant amount, 4-acetamide-TEMPO amount and reaction temperature on the properties of products were investigated. The product structures were characterized with 1H NMR for degree of oxidation (DO), SEC-MALS for MW, MS for analysis of oxidized oligosaccharides, and in-source fragmented MS for analysis of oxidized polysaccharides. The results showed that the DO of oxStarches increased, but their MWs decreased with the raise of oxidant amount; higher 4-acetamide-TEMPO amount provided higher efficiency of specific oxidation of starch, in which the product has higher DO and MW; no significant difference have been observed between the oxStarches oxidized at 4 and 25 °C, but significant degradation was observed at 50 °C. In each product, having a MW distribution, the portion with smaller size has higher DO. While some unspecific oxidation was still observed observed on the second hydroxyl groups of sugar ring in the following order of priority, position 3 > 2 > 1 > 0. Trichoderma asperellum ZZY had good tolerance to Pb2+. The polysaccharide contains a functional group which can be effectively combined with metal ions. So in this manuscript, the function and mechanism of polysaccharide on enhancing tolerance of Trichoderma asperellum were further explored. The results indicated that the polysaccharide plays vital role in Pb2+ tolerance of Trichoderma asperellum. Most lead ions adsorbed on and transferred into mycelia were accumulated in the pure polysaccharide. The proportion of uronic acid and the ratio of main chain in pure polysaccharide were increased when the strain under Pb2+ stress. These changes increase the contact area of polysaccharides with Pb2+ and the ratio of carboxyl groups to provide more binding sites for Pb2+, which is beneficial to reduce the amount of free Pb2+ and slow down the toxicity. The response changes in surface morphology and advanced structure of polysaccharide also support the conclusion. The manuscript provided theoretical basis for the application on the remediation of lead pollution.