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A pH-sensitive food packaging film was prepared based on konjac glucomannan (KGM) and hydroxypropyl methyl cellulose (HPMC) incorporated with mulberry extracts 2 (MBE). FT-IR and XRD analysis revealed that there are good molecular interactions among the three components. The incorporation of MBE into KGM and HPMC (KH) films can significantly improve the mechanical properties and UV resistance. Notably, the KH-MBE-20% film almost completely blocked UV light in the range of 200–600 nm. The best antioxidant and antibacterial properties were obtained when the addition of MBE in the composite film was 20%. In addition, KH-MBE film has good responsiveness to buffers with pH range from 2 to 12. In visual monitoring experiments using the film on fresh fish, the color of the KH-MBE film changed from purple to gray to yellow as the freshness of the fish decreased, and the KH-MBE-20% film had the best color stability. Therefore, intelligent packaging of KH-MBE film has potential applications in real-time monitoring of fish freshness.

Antibacterial films were prepared by incorporating konjac glucomannan (KGM) and gellan gum (GG) as a matrix, glycerin as a plasticizer, CaCl2 as a cross-linking agent, and gallic acid as a natural antibacterial agent. Structure was analyzed by using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Thermal stability of the blends was higher than pure GG, due to Ca2+ crosslinking between GG and KGM. Water contact angle and water vapor permeability were analyzed to determine hydrophobicity of films. Morphological studies revealed that surface compactness and homogeneity of blended films increased with KGM content. The addition of KGM improved the mechanical strength of films significantly. Moreover, KGM improved the release capacity of the blended films, while enhancing antimicrobial activity against Escherichia coli and Staphylococcus aureus. The antioxidant properties of gallic acid embedded in films were measured. Composite films containing 70 wt% KGM (Ca-KG7) displayed the best properties. These findings suggest an alternative method for synthesis of GG-based packaging films with improved properties.

Microspheres play an increasingly important role in the food and medicine industries. In this study, konjac glucomannan (KGM)/sodium alginate (SA)/graphene oxide (GO) solution was injected into CaCl2 solution under high-voltage static electricity assistance to fabricate microspheres. Then, chitosan (CS) was coated on the surface of the microspheres to enhance their stability. SEM images confirmed that increasing voltage decreased the particle size of microspheres obviously. Furthermore, GO was beneficial in maintaining the full structure of freeze-dried microspheres, and the CS membrane improved the surface of the microspheres with no relatively obvious gully. Results indicated that KGM interacted with SA by hydrogen bond, and GO improved this interaction in microspheres. Furthermore, swelling tests showed that the microspheres exhibited different swelling properties in different media, and the CS membrane could improve the stability of microspheres in simulated intestinal fluid and simulated colon fluids. Moreover, GO could greatly improve the ciprofloxacin (CPFX) loading efficiency of microspheres, and achieving a sustained release effect of CPFX. Thus, CS-coated KGM/SA/GO microspheres showed great potential application in drug and/or nutrition factor colon-targeted delivery.

The exploration of high-performance biological scaffolds with antioxidant properties and microstructures is of great scientific and technological interest. Here, we develop a facile and green strategy to construct robust konjac glucomannan/polyvinylpyrrolidone (KGM/PVP) microfiber scaffolds via microfluidic spinning technology. Epigallocatechin-3-gallate (EGCG) as a representative natural antioxidant was then loaded into the microfiber scaffolds. Then characterizations were done by scanning electron microscopy, Fourier transform-infrared spectra, IR images, X-ray diffraction, and thermogravimetric analysis, along with antioxidant characterization. The as-prepared microfiber scaffolds (the average width of the microfibers is 1 ± 0.1 μm) are of high order, transparency, thermostability, and excellent antioxidant activity (43% DPPH radical scavenging activity and 0.61 reducing force), conferring highly potential applications in wound dressing and contact lenses.

Thermosensitive hydrogels are known for their application potential in a wide range of fields. In this study, a novel thermosensitive hydrogel was prepared under specific physical gelling conditions using konjac glucomannan (KGM) and gum tragacanth (GT). The rheology results showed that KGM/GT mixed hydrocolloids are a typical non-Newtonian pseudoplastic fluid. They have significant elastic properties: G′ was higher than G″ at all hydrocolloid ratios. Increasing the GT concentration resulted in decreased tan δ values, with the extreme values occurring at KGM:GT = 3:7. Moreover, the thermosensitive hydrogels showed a sol-gel transformation temperature ranging from 40 to 35 °C. The physicochemical properties of KGM/GT hydrogels were characterized by FTIR, TGA and SEM. The intermolecular interactions were mainly hydrogen bonding. Numerous connected porous structures were found in the hydrogels microstructures. The results of this study indicate that KGM/GT thermosensitive hydrogels might be a potential material for use in food and biomedical areas.

The exploration of strategy to synthesize nanofibril film for functional applications is of great scientific and technological interest. This paper demonstrates that nanofibril film, made of biodegradable konjac glucomannan (KGM) and polyethylene oxide (PEO), performs better physical and chemical properties than solvent casting film. We fabricate a nanofibril film by electrospinning method. To collect consistent and uniform nanofibers, we explore the effect of the proportion of KGM and PEO. At proportion of KGM: PEO = 1:10, the as-prepared nanofibers are consistent in size with an average width of 200 nm. We further characterize the nanofibril film by Fourier transform infrared spectrum (FT-IR) and X-ray diffraction (XRD). The results show physical crosslinked networks between KGM and PEO chains, and modifications of the crystallization of the polymers. In addition, we disperse grape seed extract (GSE) into the electrospinning solutions to prepare bioactive nanofibril film. The as produced nanofibril film demonstrates good water vapor barrier and antioxidation function.

Hybrid organic-inorganic materials are of interest for a wide range of applications in fields of biotechnology, medical science, and green chemistry. In this study, we illustrated the principles of synthesis, the structure, and the functions of a novel konjac glucomannan (KGM) based biopolymer-silica hybrid materials. Nano-silicon dioxide (SiO2) was applied as composites, combined with KGM, to form a highly porous structure by using a simple and versatile route – freeze drying. We systematically varied the Nano-SiO2 concentration and solution pH value, the as-prepared organic-inorganic porous materials are highly ordered and highly strengthened with an average porous diameter of 100 μm, with honeycomb structure, tailored mechanical properties, and excellent support capacity. Activated carbon (AC)-loaded porous materials (CKNSi) exhibited a high Cu(II) adsorption capacity.

Pure agarose (AG) hydrogels have strong rigidity and brittleness, which greatly limit their applications. Therefore, in this study, konjac glucomannan (KGM) was used to improve the properties of AG hydrogels. The effect of KGM on the structure and properties of AG hydrogels was investigated by rotational rheometry, Fourier Transform Infrared Spectroscopy, X-ray Diffraction, and Scanning Electron Microscopy. The results showed that the flexibility of the composite hydrogels increases with KGM concentration, which may be attributed to a synergistic interaction between KGM and AG resulting in a compact network structure. In vitro drug release behavior of composite hydrogels was investigated under different environments using model drug ciprofloxacin. The results showed that the encapsulation, drug loading efficiencies, and sustained release capacity of AG hydrogels were enhanced by the incorporation of KGM. These results suggested that KGM has the potential to enhance the properties and drug release characteristics of AG hydrogels.

In this study, a novel microcapsule was generated by the encapsulation of Lactobacillus acidophilus using konjac glucomannan (KGM) hydrogel. Micropowder of L. acidophilus was mixed with gel particles, which was encapsulated in a microcapsule wall material produced by the combination of konjac oligosaccharides (KO) and sodium alginate (SA). The encapsulation and stability (both storage and digested) along with the microstructure of the capsules were analysed by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The results revealed that the microencapsulation rate was 62.5%, Dialdehyde glucomannan (DAK)/gelatin crosslinked gel formed numerous interconnected pores, and the pore wall was thick and smooth, which could well protect the microorganisms inside. Study of the storage stability showed that microencapsulated L. acidophilus could be stored for longer at both 4 °C and 25 °C. Gastric fluid simulation results confirmed that microencapsulation improved the acid resistance of L. acidophilus . An enteric test revealed that the number of viable bacteria increased with an extension of the digestion time, and no solid particles were observed in the solution after 45 min. In addition, KO was applied as both prebiotic of L. acidophilus and anti-freeze agent. It is illustrated that the survival rates of L. acidophilus (with and without encapsulated) were significantly increased during freeze drying situation. This work contributes a pathway on the construction of advanced L. acidophilus microcapsules by using KGM as a main precursor.

The exploration of methods to produce a novel wound dressing with sustained drug release properties in ultrasmall scales is of great scientific and technological interest. Herein, we propose konjac glucomannan/polyvinylidene fluoride (KGM/PVDF) hybrid microfibers having hydrophilic and hydrophobic segments based on microfluidic-oriented core–sheath composite microfibers, where the KGM/PVDF hybrid microfibers are wrapped in situ in CH3OH. The morphology of KGM/PVDF microfibers is uniform, smooth, and crack-free. Enrofloxacin (Enro) is loaded onto the microfibers as a representative cargo to test their release performance. The KGM/PVDF/Enro microfibers show sustained drug release performance (13 days), excellent heat resistance, antibacterial activity and promotion of wound healing. This study is an avenue toward the microfluidic design of hydrophilic/hydrophobic hybrid microfibers as wound dressings, and it will guide the development of next-generation wound dressing.

In this study, we synthesized a konjac glucomannan (KGM)/poly dopamine (PDA)/Oxaliplatin nanofiber membrane with efficient and controlled drug release properties by using electrospinning technology. The structure of the polymer network nanofiber membrane was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). KGM/PDA nanofiber membrane showed uniform sizes with an average diameter of 100–120 nm. The results revealed that the association of KGM and PDA to synthesize nanofiber membrane could be attributed to hydrogen bonds. Compared with KGM, the KGM/PDA nanofiber membrane exhibited higher moisture adsorption and drug release ability. Based on superior drug release ability, the KGM/PDA nanofibers provided a potential oxaliplatin carriers in application of drug release. This work contributed to a facile pathway on the construction of biomaterial nanofiber membrane by using polysaccharides. Scheme 1. Schematic presentation of the preparation of KGM/PDA nanofiber membrane and the use for drug release.

Konjac glucomannan (KGM)/galactoglucomannan (GGM) nanofiber membranes were obtained through electrospinning technology. Rheological properties of KGM/GGM solutions were observed by using a rotary rheometer. The apparent morphological, characteristic group and thermal stability of nanofiber membranes were studied through scanning electron microscopy (SEM), Fourier transform infrared spectoscopy (FTIR) and differential scanning calorimeter (DSC) respectively. The physical and mechanical properties were also evaluated. Results revealed that the addition of GGM did not significantly affect the rheological properties of electrospinning solution. Increase in the amount of GGM in the nanofiber membrane resulted in gradual smoothening, uniformity and decrease in the number of nodes. KGM interacts with GGM through hydrogen-bond. Addition of GGM markedly enhanced the thermal stability, physical and mechanical properties of the nanofiber membrane. The study showed that the KGM/GGM nanofiber membrane have good potential for use in developing membrane based materials.

The exploration of methods to produce biocompatible materials in ultrasmall scales is of great scientific and technological interest. We reported a microfluidic spinning technology (MST) for fabrication of microfibers with a novel biocompatible material, konjac glucomannan (KGM) as the main material combined with sodium polyacrylate (PAAS). These as-produced KGM/PAAS microfibers are consistent and uniform in size with an average width of 100 μm. Also, these microfibers can easily arrange to microarrays and microgrids, facilely forming a useful platform for molecules recognition of amines. Moreover, the nontoxicity of KGM developed an ofloxacin loaded KGM microfibers present potential application in wound dressing. This strategy contributes a facile pathway on the construction of biomaterial microfibers by using polysaccharides as the precursors.

In this study, a facile marine bioinspired surface modification approach for carboxyl-functionalized multiwalled carbon nanotube (CCNT) and enhanced interfacial adhesion with the konjac glucomannan (KGM) matrix were illustrated to develop aerogels. Combined with FT-IR, XRD, Raman, TGA, XPS and SEM results, it was indicated that functionalized CCNT (PCCNT) is a reinforcer through hydrogen bond interactions in the aerogel formation process, which could be the main reason for the enhancement. The swelling and vitro release behavior of KGM/PCCNT aerogels were studied under two conditions using the drug 5-fluorouracil (5-FU). The release amount of 5-FU incorporated into KGM/PCCNT4 aerogel was about 48% at pH 1.2 and 62% at pH 6.8 after11 h, respectively. The results showed that the release rate of 5-FU from the KGM/PCCNT4 aerogel using PCCNT could be effectively controlled, suggesting potential applications for it as a drug carrier in targeted delivery in the biomedical filed.

The development of konjac glucomannan (KGM) based films for use in food packaging has aroused increasing attention due to biodegradability, compatibility, and availability. Epigallocatechin gallate (EGCG) loaded dialdehyde glucomannan (DG) was incorporated into a gelatin (G) solution to improve the functional properties of DGG film. Rutin functionalized cellulose nanocrystal (RCNC) was incorporated into a DG/G matrix (DGG). The influences of RCNC addition on the structural, mechanical properties, barrier and optical properties were investigated. The RCNC@DGG films were prepared by the solvent casting method. The surface morphology of the RCNC@DGG films were analyzed by SEM and AFM. The crystal structure and thermal ability of the film were investigated by XRD and TGA-DTG. Elemental and characteristic peak changes were evaluated by FT-IR. The microstructure of the films showed that the introduced RCNC appeared to be dispersed within the DGG matrix, thereby decreasing the free volume, and enhancing RCNC@DGG films' mechanical and barrier properties. Compared with DGG film, RCNC@DGG nanocomposite films showed excellent antibacterial activity against food-borne pathogens, due to the antibacterial property of the EGCG. Therefore, RCNC@DGG nanocomposite films showed the potential for applications in active food packaging materials.

A novel EGCG-loaded DCKGM-CCKGM-Fe3+hydrogel was prepared by Dopamine-carboxymethyl konjac glucomannan (DCKGM) and an l-Cysteine-carboxymethyl konjac glucomannan (CCKGM) with Fe3+ as a cross-linking agent. Due to the dynamic property of Fe3+-phenolic hydroxyl coordination bond and intermolecular hydrogen bonding, the resultant hydrogel featured injectable, adhesive, temperature and pH-sensitive properties. The mechanisms were characterized using Rheological analysis, Fourier transform infrared spectroscopy, X-ray diffraction patterns, and scanning electron microscopy. Furthermore, the weak alkaline condition (pH 7.4) can trigger the release of EGCG, there was a cumulative release of 54.71 % of the loaded EGCG within 12 h in PBS at pH 1.2. When the pH of PBS was increased to 7.4, the cumulative release of EGCG increased to 68.54 %. Consequently, the EGCG-loaded DCKGM-CCKGM-Fe3+hydrogel (Fe3+Hydrogel) is a good candidate for the carrier for drug delivery. This paper provided a novel way for the preparation of hydrogel.

The exploration of methods to produce biomaterials with antibacterial properties in ultra-small scales is of great scientific and technological interest. Here, we reported a microfluidic spinning approach to prepare a novel film combined with konjac glucomannan (KGM), polyvinylpyrrolidone (PVP), and epigallocatechin gallate (EGCG). The film was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis. This film was transparent, orderly, thermally stable, and uniform in size, with an average width less than 1 μm. Also, the film exhibited excellent antibacterial efficiency (97.1% against E. coli, 99.7% against S. aureus, 97.3% against S. enterica and 99.9% against B. subtilis) in our antibacterial test. In addition, the film promoted wound healing with the advanced development of neovascularization and hair follicles. This strategy provides a facile and green pathway for the construction of biomaterial films for medical applications.

Three-dimensional nanofibers cryogels (NFCs) with both thermally-tolerant and mechanically-robust properties have potential for wide application in biomedical or food areas; however, creating such NFCs has proven to be extremely challenging. In this study, konjac glucomannan (KGM)/poly (lactic acid) (PLA)-based novel NFCs were prepared by the incorporation of the mussel-inspired protein polydopamine (PDA) via a facile and environmentally-friendly electrospinning and freeze-shaping technique. The obtained KGM/PLA/PDA (KPP) NFCs were characterized by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and compressive and tensile test. The results showed that the hierarchical cellular structure and physicochemical properties of KPP NFCs were dependent on the incorporation of PDA content. Moreover, the strong intermolecular hydrogen bond interactions among KGM, PLA and PDA also gave KPP NFCs high thermostability and mechanically-robust properties. Thus, this study developed a simple approach to fabricate multifunctional NFCs with significant potential for biomedical or food application.

Intelligent hydrogels are attractive biomaterials for various applications, however, fabricating a hydrogel with both adequate self-healing ability and mechanical properties remains a challenge. Herein, a series of novel intelligent konjac glucomannan (KGM)/microcrystalline cellulose (MCC) hydrogels were prepared vis the mussel-inspired chemistry. MCC was firstly functionalized by the oxidative polymerization of dopamine, and the intelligent hydrogels were obtained by mixing aqueous solutions of KGM and functionalized MCC (PDMCC). By introducing PDMCC, a more compact interconnected porous structure formed for the resulting hydrogels. The self-healing ability and mechanical properties of intelligent hydrogels were dependence on the PDMCC content. Compared with KGM hydrogels, KGM/PDMCC hydrogels exhibited a more distinct pH sensitivity and a lower initial burst release, which was attributed to the compact structure and strong intermolecular hydrogen bond interaction between PDMCC and KGM. These results suggest that the KGM/PDMCC intelligent hydrogels may be promising carriers for controlled drug delivery.

Konjac glucomannan (KGM) has attracted extensive attention because of its biodegradable, non-toxic, harmless, and biocompatible features. Its gelation performance is one of its most significant characteristics and enables wide applications of KGM gels in food, chemical, pharmaceutical, materials, and other fields. Herein, different preparation methods of KGM gels and their microstructures were reviewed. In addition, KGM applications have been theoretically modeled for future uses.

The exploration of methods to produce biodegradable and bioactive nanofibril films is of great scientific and technological interests. We reported a strategy to constructing of nanofibril films by using konjac glucomannan (KGM) and zein via electrospinning technology. The characterization of the nanofibril films was conducted via Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and water contact angle measurements. The interactions of hydrogen bonds between KGM and zein were confirmed, and the addition of zein caused an increase of thermal properties and hydrophobicity. The morphology and size of nanofibers significantly depended on zein contents. We further loaded curcumin (Cur), a natural polyphenolic compound, within the KGM/Zein/Cur nanofibril films to investigate the antibacterial and antioxidating properties for the novel nanofibril films. In comparison with a pure KGM and zein film, KGM/Zein/Cur nanofibril films indicated an excellent antibacterial activity against food-borne pathogens. Our work suggested that the KGM/Zein/Cur nanofibril films had a potential application in food packaging, which opens a facile pathway to the modification of KGM-based biopolymer to form nanofilms.

Konjac glucomannan (KGM) hydrogel has good potential application in food and medical science, although to achieve this, the physical and mechanical properties need further improvement. In this study, graphene oxide (GO) was used to improve the functionality of KGM hydrogel. KGM/GO hydrogels were prepared by freezing the alkaline KGM/GO sols. Rotational rheometer was used to study the rheological properties of different alkaline KGM/GO sols. Fourier transform infrared, Raman, differential scanning calorimetry, thermogravimetric analyses, and scanning electron microscopy were used to evaluate the structure and properties of the hydrogels. In addition, different pH solutions and an in vitro assay were used to study the swelling property and the release behavior of KGM/GO hydrogels, respectively. The result revealed strong hydrogen-bond interaction between KGM and GO. The incorporation of GO highly improved the gel properties of KGM/GO sol, higher thermal stability, and more compact structure of KGM/GO hydrogels. KGM/GO hydrogels showed better swelling properties in deionized-distilled water and pH 7.2 PBS. The release of 5-aminosalicylic acid (5-ASA) from KGM/GO (KG4) hydrogel was different in various pH media, but the initial burst release effect was very severe. Therefore, incorporation of GO have a good potential in enhancing the properties of KGM hydrogel, but KGM/GO hydrogel is not an ideal carrier for 5-ASA release. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45327.