Structural and Physiochemical Properties of Polyvinyl Alcohol-Succinoglycan Biodegradable Films.

Polyvinyl alcohol (PVA)-bacterial succinoglycan (SG) biodegradable films were developed through a solvent-casting method. Effects of the PVA/SG ratio on the thickness, transmittance, water holding capacity, and structural and mechanical properties were investigated by various analytical methods. All the prepared films were transparent and uniform, and XRD and FTIR analyses confirmed that PVA was successfully incorporated into SG.

Drug delivery using reduction-responsive hydrogel based on carboxyethyl-succinoglycan with highly improved rheological, antibacterial, and antioxidant properties.

The development of exopolysaccharide-based polymers is gaining increasing attention in various industrial biotechnology fields for materials such as thickeners, texture modifiers, anti-freeze agents, antioxidants, and antibacterial agents. High-viscosity carboxyethyl-succinoglycan (CE-SG) was directly synthesized from succinoglycan (SG) isolated from Sinorhizobium meliloti Rm 1021, and its structural, rheological, and physiological properties were investigated. The viscosity of CE-SG gradually increased in proportion to the degree of carboxyethylation substitution.

Rhizobial oxidized 3-hydroxylbutanoyl glycan-based gelatin hydrogels with enhanced physiochemical properties for pH-responsive drug delivery.

Rhizobial exopolysaccharide (EPS) is an acidic polysaccharide involved in nitrogen fixation-related signal transduction in the rhizosphere, serving as a structural support for biofilms, and protecting against various external environmental stresses. Rhizobial EPS as a hydrogel biomaterial was used for a pH-responsive drug delivery system combing with gelatins. Pure gelatin (GA) hydrogels have limited practical applications due to their poor mechanical strength and poor thermal stability.

Physicochemical and Rheological Properties of Succinoglycan Overproduced by 1021 Mutant.

Commercial bacterial exopolysaccharide (EPS) applications have been gaining interest; therefore, strains that provide higher yields are required for industrial-scale processes. Succinoglycan (SG) is a type of bacterial anionic exopolysaccharide produced by , , and other soil bacterial species. SG has been widely used as a pharmaceutical, cosmetic, and food additive based on its properties as a thickener, texture enhancer, emulsifier, stabilizer, and gelling agent.

Structural, rheological properties and antioxidant activities analysis of the exopolysaccharide produced by Rhizobium leguminosarum bv. viciae VF39.

Microbial exopolysaccharide is an eco-friendly and non-toxic biopolymeric materials widely used in various industrial fields such as pharmaceutical, food and cosmetics based on its structural, rheological and physiochemical properties. A microbial exopolysaccharide (VF39-EPS) was directly isolated from Rhizobium leguminosarum bv. viciae VF39.

New Polyvinyl Alcohol/Succinoglycan-Based Hydrogels for pH-Responsive Drug Delivery.

We fabricated new hydrogels using polyvinyl alcohol (PVA) and succinoglycan (SG) directly isolated and obtained from Rm 1021 via the freeze-thaw method. Both the composition of the hydrogels and the freeze-thaw cycles were optimized to maximize the swelling ratio for the preparation of the PVA/SG hydrogels. During the optimization process, the morphology and conformational change in the hydrogel were analyzed by scanning electron microscopy, rheological measurements, and compressive tests.

A pH-sensitive drug delivery using biodegradable succinoglycan/chitosan hydrogels with synergistic antibacterial activity.

Since succinoglycan (SG) produced by Sinorhizobium meliloti is an anionic polysaccharide having substituents such as succinate and pyruvate groups, a polyelectrolyte composite hydrogel can be made together with chitosan (CS), a cationic polysaccharide. We fabricated polyelectrolyte SG/CS hydrogels using the semi-dissolving acidified sol-gel transfer (SD-A-SGT) method. The hydrogel showed optimized mechanical strength and thermal stability at an SG:CS weight ratio of 3:1.

Novel succinoglycan dialdehyde/aminoethylcarbamoyl-β-cyclodextrin hydrogels for pH-responsive delivery of hydrophobic drugs.

β-Cyclodextrin cross-linked succinoglycan dialdehyde hydrogels was prepared for hydrophobic drug delivery. Succinoglycan dialdehyde (SGDA) was synthesized from sodium periodate oxidation of succinoglycan isolated from Sinorhizobium meliloti Rm1021. Aminoethylcarbamoyl-β-cyclodextrin (ACD) was crosslinked with SGDA to form a succinoglycan dialdehyde/aminoethylcarbamoyl-β-cyclodextrin (SGDA/ACD) hydrogels.

Multifunctional Oxidized Succinoglycan/Poly(N-isopropylacrylamide-co-acrylamide) Hydrogels for Drug Delivery.

We prepared the self-healing and temperature/pH-responsive hydrogels using oxidized succinoglycan (OSG) and a poly (N-isopropyl acrylamide-co-acrylamide) [P(NIPAM-AM)] copolymer. OSG was synthesized by periodate oxidation of succinoglycan (SG) isolated directly from soil microorganisms, Rm1021. The OSG/P(NIPAM-AM) hydrogels were obtained by introducing OSG into P(NIPAM-AM) networks.

Mechanism of cyclic β-glucan export by ABC transporter Cgt of Brucella.

Polysaccharides play critical roles in bacteria, including the formation of protective capsules and biofilms and establishing specific host cell interactions. Their transport across membranes is often mediated by ATP-binding cassette (ABC) transporters, which utilize ATP to translocate diverse molecules. Cyclic β-glucans (CβGs) are critical for host interaction of the Rhizobiales, including the zoonotic pathogen Brucella.

Injectable, self-healable and adhesive hydrogels using oxidized Succinoglycan/chitosan for pH-responsive drug delivery.

We prepared chitosan (CS) based multifunctional hydrogels using oxidized succinoglycan (OSG) with a semi-dissolving acidified sol-gel transition method. OSG cross-linked CS hydrogels (OSG/CS) was prepared by aldehyde-amine Schiff-base reaction. OSG/CS increased not only thermal stability but also improved mechanical strength by 5.

Bacterial Succinoglycans: Structure, Physical Properties, and Applications.

Succinoglycan is a type of bacterial anionic exopolysaccharide produced from , , and other soil bacteria. The exact structure of succinoglycan depends in part on the type of bacterial strain, and the final production yield also depends on the medium composition, culture conditions, and genotype of each strain. Various bacterial polysaccharides, such as cellulose, xanthan, gellan, and pullulan, that can be mass-produced for biotechnology are being actively studied.

pH-Responsive Succinoglycan-Carboxymethyl Cellulose Hydrogels with Highly Improved Mechanical Strength for Controlled Drug Delivery Systems.

Carboxymethyl cellulose (CMC)-based hydrogels are generally superabsorbent and biocompatible, but their low mechanical strength limits their application. To overcome these drawbacks, we used bacterial succinoglycan (SG), a biocompatible natural polysaccharide, as a double crosslinking strategy to produce novel interpenetrating polymer network (IPN) hydrogels in a non-bead form. These new SG/CMC-based IPN hydrogels significantly increased the mechanical strength while maintaining the characteristic superabsorbent property of CMC-based hydrogels.

Synthesis and Application of Silica-Coated Quantum Dots in Biomedicine.

Quantum dots (QDs) are semiconductor nanoparticles with outstanding optoelectronic properties. More specifically, QDs are highly bright and exhibit wide absorption spectra, narrow light bands, and excellent photovoltaic stability, which make them useful in bioscience and medicine, particularly for sensing, optical imaging, cell separation, and diagnosis. In general, QDs are stabilized using a hydrophobic ligand during synthesis, and thus their hydrophobic surfaces must undergo hydrophilic modification if the QDs are to be used in bioapplications.

Fabrication of Flexible pH-Responsive Agarose/Succinoglycan Hydrogels for Controlled Drug Release.

Agarose/succinoglycan hydrogels were prepared as pH-responsive drug delivery systems with significantly improved flexibility, thermostability, and porosity compared to agarose gels alone. Agarose/succinoglycan hydrogels were made using agarose and succinoglycan, a polysaccharide directly isolated from . Mechanical and physical properties of agarose/succinoglycan hydrogels were investigated using various instrumental methods such as rheological measurements, attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopic analysis, X-ray diffraction (XRD), and field-emission scanning electron microscopy (FE-SEM).

Biomacromolecules, Biobased and Biodegradable Polymers: 2018-2019.

This editorial introduces the most cited papers published in the years 2018-2019 in the section "Biomacromolecules, Biobased and Biodegradable Polymers" of the journal Polymers [...

Fabrication and Characterization of Polysaccharide Metallohydrogel Obtained from Succinoglycan and Trivalent Chromium.

In the present study, a polysaccharide metallohydrogel was successfully fabricated using succinoglycan and trivalent chromium and was verified via Fourier transform infrared spectroscopy, differential scanning calorimetry analysis, thermogravimetric analysis (TGA), field emission scanning electron microscopy, and rheological measurements. Thermal behavior analysis via TGA indicated that the final mass loss of pure succinoglycan was 87.8% although it was reduced to 65.

Biocompatible and self-recoverable succinoglycan dialdehyde-crosslinked alginate hydrogels for pH-controlled drug delivery.

We fabricated polysaccharide-based hydrogels, which are biocompatible, self-recoverable and pH-sensitive. Succinoglycan dialdehyde (SGDA) was first synthesized from bacterial succinoglycan directly isolated from Sinorhizobium meliloti and then hydrazine-functionalized alginate (HZ-Alg) was prepared to form SGDA-crosslinked alginate hydrogels (SGDA/HZ-Alg) without any catalyst. Due to structural characteristics of SGDA, SGDA/HZ-Alg were effectively obtained in a short time even at low concentrations (0.

Structural Characterization of Glycerophosphorylated and Succinylated Cyclic β-(1→2)-d-Glucan Produced by 1021.

produces different types of surface polysaccharides. Among them, cyclic β-(1→2)-d-glucan is located in the periplasmic space of rhizobia and plays an important role in the adaptation of bacteria to osmotic adaptation. Cyclic β-(1→2)-d-glucan (CG), synthesized from 1021, has a neutral and anionic form.

Azobenzene-grafted carboxymethyl cellulose hydrogels with photo-switchable, reduction-responsive and self-healing properties for a controlled drug release system.

In this study, multifunctional hydrogels containing host-guest complex formation between azobenzene-grafted carboxymethyl cellulose (CMC-Azo) and β-cyclodextrin (CD) dimers connected by disulfide bonds with agarose for structural support were prepared. The obtained hydrogels exhibited self-healing properties by host-guest complexation as well as gel-sol phase transition in response to ultraviolet (UV) light and reducing agents. Photo-switchable properties of the hydrogels depend on changes in the complex formation of CD-dimers through the trans(450 nm) to cis(365 nm) photo-isomerization of azobenzene.

Preparation of Succinoglycan Hydrogel Coordinated With Fe Ions for Controlled Drug Delivery.

Hydrogel materials with a gel-sol conversion due to external environmental changes have potential applications in a wide range of fields, including controlled drug delivery. Succinoglycans are anionic extracellular polysaccharides produced by various bacteria, including species, which have diverse applications. In this study, the rheological analysis confirmed that succinoglycan produced by Rm 1021 binds weakly to various metal ions, including Fe cations, to maintain a sol form, and binds strongly to Fe cations to maintain a gel form.

Utilization of Water-Soluble Aminoethylamino-β-Cyclodextrin in the Pfitzinger Reaction-Catalyzed to the Synthesis of Diversely Functionalized Quinaldine.

In this study we describe the use of an aminoethylamino-β-cyclodextrin (AEA-β-CD) as a supramolecular homogeneous catalyst for the synthesis of a series of diversely substituted quinaldine derivatives which are medicinally important, via Pfitzinger reaction. This supramolecular catalyst exhibited remarkable catalytic activity with high substrate scope to achieve the synthetic targets in good to excellent yield, 69-92%. The structural and morphological properties of the synthesized AEA-β-CD were determined through MALDI-TOF mass spectrometry, NMR, FT-IR, and SEM analysis.

Succinoglycan dialdehyde-reinforced gelatin hydrogels with toughness and thermal stability.

Pure gelatin hydrogel (PG) has limited practical applications due to their thermal instability and unfavorable mechanical properties. To overcome these limitations, dually crosslinked hydrogels were developed by imparting chemical crosslinking to existing physically crosslinked gelatin hydrogel networks using succinoglycan dialdehyde (SGDA) as a macromolecular crosslinker. SGDA-reinforced gelatin hydrogels (SGDA/Gels) displayed an 11 times higher compressive stress under identical deformation strain and a 1040% improvement in storage modulus (G') than PG.

Mono-6-Deoxy-6-Aminopropylamino--Cyclodextrin on Ag-Embedded SiO Nanoparticle as a Selectively Capturing Ligand to Flavonoids.

It has been increasingly important to develop a highly sensitive and selective technique that is easy to handle in detecting levels of beneficial or hazardous analytes in trace quantity. In this study, mono-6-deoxy-6-aminopropylamino--cyclodextrin (pr--CD)-functionalized silver-assembled silica nanoparticles (SiO@Ag@pr--CD) for flavonoid detection were successfully prepared. The presence of pr--CD on the surface of SiO@Ag enhanced the selectivity in capturing quercetin and myricetin among other similar materials (naringenin and apigenin).