Journal of Materials Chemistry B
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2020
·Vol. 8
·期 43
·9921-9932
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IF 5.344
Min Ge,Yaqi Sheng,Shuyue Qi,Lei Cao,Yan Zhang,Jun Yang
Incorporating poly(lactic-co-glycolic) acid (PLGA) microparticles into human mesenchymal stem cells (hMSC) aggregates has shown promising application prospects. However, the acidic degradation products and burst release of PLGA microparticles still need to be ameliorated. In this study, the PLGA/chitosan–heparin (P/C–h) composite microparticles were successfully fabricated by integrating the double emulsion and microfluidic technology through the precise manipulation of the emulsion composition and flow rate of the two-phase in a flow-focusing chip. The P/C–h microparticles were highly monodispersed with a diameter of 23.45 ± 0.25 μm and shell–core structure of the PLGA encapsulated C–h complex, which were suitable for the fabrication of hMSC aggregates. When the mass ratio of PLGA to the C–h complex was optimized to 2 : 1, the pH of the leach liquor of P/C–h microparticles remained neutral. Compared with those of PLGA microparticles, the cytotoxicity and the initial burst release (loaded FGF-2 and VEGF) were both significantly reduced in P/C–h microparticles. Furthermore, the survival, stemness, as well as secretion and migration abilities of cells in hMSC aggregates incorporating P/C–h microparticles were also enhanced. In summary, the P/C–h composite microparticles prepared by the droplet microfluidic technique support the optimal biological and functional profile of the hMSC aggregates, which may facilitate the clinical applications of MSC-based therapy.
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FOOD HYDROCOLLOIDS
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2020
·
IF 7.053
Xinhui Zhang,Yintao Li,Mingming Guo,Tony Z. Jin,Saifanassour Ali Arabi,Qiao He,Balarabe B. Ismail,Yaqin Hu,Donghong Liu
Chitosan has attracted much attention for use in antimicrobial food packaging because of its unique antibacterial properties and excellent film-forming ability. However, its poor barrier properties to UV light and high water-solubility limit its application. In this study, modified cellulose nanofiber was incorporated into chitosan films to improve their UV blocking, physical, and antibacterial properties. Modified cellulose nanofiber was obtained by grafting curcumin to 2, 2, 6, 6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose. Infrared spectroscopy and X-ray photoelectron spectroscopy results indicated that cellulose was successfully modified. Bio-nanocomposite films composed of chitosan (67–100 wt %) and curcumin grafted TEMPO-oxidized cellulose nanofiber (CGTOCNF, 0–33 wt %) were prepared using the casting method. Scanning electron microscopy images and X-ray diffraction analysis showed that the addition of CGTOCNF noticeably affected the morphology of the composite films, with the crystallinity significantly increasing from 21.93% to 87.15%. Moreover, CGTOCNF incorporation improved the oxidation resistance and UV blocking properties of the composite films compared to pure chitosan films. It is also worth mentioning that all of the composite films have excellent antibacterial activity with CGTOCNF partially replacing chitosan. Furthermore, the water solubility of films decreased with the incorporation of CGTOCNF. However, this study demonstrated that incorporation of CGTOCNF at concentrations greater than 10% resulted in a slight decrease in the water vapor barrier properties and mechanical strength of chitosan films. The findings in this work indicate that the addition of 10% CGTOCNF to chitosan films enhances their physical and antibacterial properties, thus increasing their potential for use in food packaging.
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RSC Advances
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2020
·Vol. 10
·期 73
·45171-45179
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IF 3.119
Huimin Liang,Caizhi Lv,Hanjiao Chen,Lan Wu,Xiandeng Hou
Due to the film-forming ability of polymers, a variety of photocatalytic membranes (PMs) based on polymers easily being separated and reused have been constructed for wastewater contaminant treatment. During their construction processes, chitosan (CS) as a bio-polymer with its distinct merits of abundant resources, low-cost and environmental-friendliness, as well as formability and ease of modification, has attracted great attention. However, the role of CS was mostly believed to be just a support or an adsorbent for fixing or dispersing photocatalysts. Whether CS possessed photocatalytic activity or not still remained vague. Herein, in this work, CS membranes (CSM) were facilely prepared for photocatalytic degradation of tetracycline hydrochloride (TC, a model organic pollutant) in aqueous solution, and its photocatalytic performance was investigated and compared with that of CSP (CS powder) and TiO2-P25 (a commercially used photocatalyst). The results showed that the single-phased CSM exhibited a better visible light photocatalytic activity. After visible light irradiation for 60 minutes, the degradation efficiency of TC can reach above 90% when the CSM was used as a photocatalyst, while with the same irradiation time interval, less TC could be degraded over both CSP and TiO2-P25. Through radical scavenging and EPR experiments, ˙O2− and h+ were found to be the main active oxygen species generated in the reaction system for TC degradation. After being washed with 2 wt% NaOH solution, the CSM revealed a good recyclability implying its potential for practical applications. This study would provide a certain theoretical and data basis for the future development of CS-based PMs and photocatalysts.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2020
·Vol. 138
·期 12
·50065
·
IF 2.52
Jingqi Luo,Chuanjie Fan,Xiaodong Zhou
A new type of polydopamine functionalized graphene oxide/carboxymethyl chitosan (DGO/CMC) composite aerogels was synthesized via sol–gel once-forming self-assembly and lyophilization. Polydopamine (PDA) on the surface of GO nanosheets replaced those traditional crosslinking agents to connect CMC chains via hydrogen bonding for the establishment of 3D porous aerogels. With the increasing proportion of CMC, the microstructure of aerogels changed from small pores to large plate-bridge-like pores. In addition, their maximum compressive strengths were 6.767, 11.94, and 16.98 MPa under 90% compressions, respectively, which increased in accordance with CMC content. Furthermore, the adsorption system of the aerogels was simulated well by the pseudo second-order kinetic model and the Langmuir isotherm model, with maximum mass adsorption capacities of 170.3, 186.8, and 312.8 mg/g for Cu 2+ , Ni 2+ , and Pb 2+ ions, respectively. These composite materials have potential applications for water purification because of their simple and efficient synthesis and excellent recyclability and reusability.
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CARBOHYDRATE POLYMERS
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2020
·
IF 7.182
Dong-Wei Wang,Shu-Juan Li,Xue-Ying Tan,Jin-Hui Wang,Ying Hu,Zeng Tan,Jing Liang,Jing-Bo Hu,Yan-Guo Li,Yu-Fen Zhao
Acute kidney injury (AKI) is a common and serious clinical syndrome of acute renal dysfunction in a short period. One of therapeutic interventions for AKI is to reduce ROS massively generated in the mitochondria and then ameliorate cell damage and apoptosis induced by oxidative stress. In this study, stepwise-targeting chitosan oligosaccharide, triphenyl phosphine-low molecular weight chitosan-curcumin (TPP-LMWC-CUR, TLC), was constructed for sepsis-induced AKI via removing excessive ROS in renal tubular epithelial cells. Benefiting from good water solubility and low molecular weight, TLC was rapidly and preferentially distributed in the renal tissues and then specifically internalized by tubular epithelium cells via interaction between Megalin receptor and LMWC. The intracellular TLC could further delivery CUR to mitochondria due to high buffering capacity of LMWC and delocalized positive charges of TPP. Both in vitro and in vivo pharmacodynamic results demonstrated the enhanced therapeutic effect of TLC in the treatment of AKI.
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CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Wenbo Zhang,Henghui Deng,Lijuan Xia,Lan Shen,Chaoqun Zhang,Qiming Lu,Shaolong Sun
A series of vegetable oil-based waterborne polyurethane composites were prepared through construction of novel semi-interpenetrating polymers network using carboxymethyl chitosan (CA) as the secondary polymer phase. The effects of CA contents on storage stability, and particle size distribution of the composite dispersions and thermal stability, mechanical properties and surface wettability of composite films were investigated and discussed. The results showed that the composite dispersions displayed excellent storage stability and the biomass contents of resulting films were high up to 80 %. A significant increase in crosslinking density and glass transition temperature of the composite films were observed as the CA contents increased, which was attributed to the increasing hard segment of films and strong hydrogen bonding interaction between polyurethanes and CA. This work provided a simple method to tailor the performance of environmentally friendly vegetable oil-based waterborne polyurethane, which could find application in the field of coatings, adhesives, ink and so on.
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ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Yinying Sheng,Junjie Yang,Xueyang Zhao,Hui Liu,Shaogang Cui,Lianxi Chen,Rong Zeng,Xiaojian Wang,Chi-Hsien Huang,Wei Li
Zinc (Zn) alloys are promising alternatives to magnesium (Mg)- and iron (Fe)-based alloys because of their moderate corrosion rate and superior biocompatibility. To reduce the mass release of Zn2+ and improve the biocompatibility of Zn implants, the biomimetic zwitterionic polymer layer (phosphorylcholine chitosan—PCCs) was immobilized on the plasma-treated Zn1Mg surface. It is the chemical bonds between the −NH2 groups of the PCCs chain and O–C═O (C═O) groups on the plasma-treated Zn1Mg (Zn1Mg-PP) that contributes to the strong bonding strength between the film and the substrate, by which the PCCs (approx. 200 nm thick) layer can bear a 5.93 N normal load. The electrochemical impedance spectroscopy (EIS) results showed that the PCCs layer remarkably increased the resistance against corrosion attack, protecting substrates from over-quick degradation, and the protective effect of the layer with a thickness of 200 nm lasts for about 24 h. The corrosion products of Zn1Mg-PP-PCC in NaCl solution were determined as Zn5(OH)8Cl2·H2O and Zn3(PO4)2. Besides, the bulk Zn1Mg can trigger more aggressive macrophage activity, while the surface of Zn1Mg-PP and Zn1Mg-PP-PCC and their corrosion products (Zn3(PO4)2) tend to promote the differentiation of macrophages into the M2 phenotype, which is beneficial for implant applications.
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JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 56
·期 1
·706-717
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IF 3.553
Wen Jing,Liao Jianguo,Ying Qiwei,Li Hang,Mao Yanrui,Han Suyan,Zhu Yu
Ideal inorganic bone cement used for bone repair should have high strength, and the speed of degradation should match the formation rate of new bone tissue. Magnesium oxychloride cement has excellent mechanical properties and non-toxicity to bone marrow stromal cells; however, its application has been hindered by its poor water resistance. In this study, the high-degradation material chitosan (CS) was added to magnesium oxychloride cement (MOC). The compressive strength, mass loss, ion release, and pH value of the composite MOC were analyzed and scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy were conducted. The compressive strength was 45.4 ± 5.3 MPa in cements with 0.5-wt% CS and 2-wt% KH 2 PO 4 soaked in SBF for 28 d, and the degradation rate reached 12.67 ± 0.5%. SEM observations showed good apatite formation of the surfaces of the MOC with 2-wt% KH 2 PO 4 and with 0.5-wt% CS and 2-wt% KH 2 PO 4 . The results indicate that the modified MOC possesses good mechanical properties, degradation rate and biological properties. Therefore, it is a promising material for degradable bone filling.
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CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Chao Xu,Shui Guan,Jianqiang Xu,Weitao Gong,Tianqing Liu,Xuehu Ma,Changkai Sun
In this study, protocatechuic acid (PCA) was grafted onto carboxymethyl chitosan (CMCS) via EDC/NHS to improve the antioxidant effect. The grafting ratio of PCA-g-CMCS conjugates could be controlled by adjusting the pH value and feed ratio of raw materials. The conjugates exhibited similar pH sensitivity to CMCS and showed dramatic enhancements of DPPH and ABTS radicals scavenging activities, total antioxidant capacity, reducing power, and Fe 2+ -chelating activity. Three-dimensional porous PCA-g-CMCS hydrogel was prepared by lyophilization and secondary cross-linking. The shaped hydrogel preserved its antioxidant activity, and the sustained release of PCA-containing degraded fragment from biodegradable hydrogel could be achieved with the aid of lysozyme in vitro (15 days). PCA-g-CMCS hydrogel also showed excellent biocompatibility and protective effect on H 2 O 2 -induced oxidative damage in SH-SY5Y cells. These results suggested that PCA-g-CMCS conjugates and its hydrogel would appear to be a promising oxidation-resistant material for applications such as drug release and tissue engineering.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2020
·
IF 5.162
Zichao Yin,Xiaojun Sun,Mutai Bao,Yang Li
Hydrophobic/oleophilic absorbents have been largely studied and used in recovering spilled oil. However, they still suffer from several drawbacks and two of them are poor biocompatibility and hard to thoroughly rinse. In order to address these problems, here a hydrophobic magnetic chitosan-based aerogel is fabricated via electrostatic interactions between chitosan (CS), itaconic acid (IA) and Fe 3 O 4 nanoparticles and dip-coating in ethanol solution of Candelilla wax (CW). Due to the interconnected porous structure of chitosan-based aerogel, the magnetism of Fe 3 O 4 nanoparticles and the hydrophobicity of CW, the prepared aerogel exhibits high absorption capacities (from 17.7 to 43.8 g/g) towards various types of organic liquids, excellent magnetic controllability with saturation magnetization of 15.93 emu/g and good water repellency with water contact angle (WCA) of 147.9°. In addition, the aerogel can also continuously separate immiscible oil/water mixtures and water-in-oil emulsions as the form of filter. More significantly, the absorbed organic liquids can be completely recovered by simply placing the aerogel in water solution of IA at 75 °C, which can avoid cleaning agent consumption. As a consequence, this renewable, biodegradable and eco-friendly oil scavenger presents a bright prospect in practical applications.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Xingwei Wang,Fangyuan Cheng,Xuejiao Wang,Tingting Feng,Shuqin Xia,Xiaoming Zhang
In this work, cinnamaldehyde-loaded liposomes decorated with different concentrations of chitosan (0, 0.25, 0.5, 1, 2, 3, and 4 mg/mL) were prepared and their physical and antibacterial properties were evaluated. The results showed that the physical decoration of chitosan improved the encapsulation efficiency and storage stability of the liposomes. Liposomes decorated with chitosan at the concentration of 0.25 to 4 mg/mL were able to achieve an obvious antibacterial efficiency against Staphylococcus aureus after only 10 min of incubation. The antibacterial efficiency of chitosan-decorated liposomes was still higher than 90% after being stored for 28 d when the chitosan concentration was greater than 1 mg/mL. Besides, increasing the chitosan concentration significantly decreased the minimum inhibitory concentration of the liposomes. The comparison of the antibacterial activities and mechanisms of cinnamaldehyde-loaded liposomes decorated with chitosan at a concentration of 4 mg/mL (CH-CL), cinnamaldehyde-loaded liposomes (CL), cinnamaldehyde, and chitosan revealed that chitosan and cinnamaldehyde exerted a cumulative and synergistic bacteriostatic effect in the liposomes. This led to damage to the cell membrane integrity, causing cell death by inducing leakage of intracellular components. These results can potentially provide guidance for the preparation and application of natural preservatives with rapid and long-term bacteriostatic effects.
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Polymers
·
2020
·Vol. 12
·期 10
·2268
·
IF 3.426
Song Feng,Junqin Wang,Lihua Zhang,Qin Chen,Wang Yue,Ni Ke,Haibo Xie
Currently, controlled release formulations (CRFs) of pesticides in response to biotic and/or abiotic stimuli have shown great potential for providing “on-demand” smart release of loaded active ingredients. In this study, amphiphilic biopolymers were prepared by introducing hydrophobic (7-diethylaminocoumarin-4-yl)methyl succinate (DEACMS) onto the main chain of hydrophilic carboxymethylchitosan (CMCS) via the formation of amide bonds which were able to self-assemble into spherical micelles in aqueous media and were utilized as light-responsive nanocarriers for the controlled release of pesticides. FTIR and NMR characterizations confirmed the successful synthesis of the CMCS-DEACMS conjugate. The critical micelle concentration (CMC) decreased with the increase in the substitution of DEACMS on CMCS, which ranged from 0.013 to 0.042 mg/mL. Upon irradiation under simulated sunlight, the hydrodynamic diameter, morphology, photophysical properties and photolysis were researched by means of dynamic light scattering (DLS), transmission electron microscopy (TEM), UV-vis absorption spectroscopy and fluorescence spectroscopy. Moreover, 2,4-dichlorophenoxyacetic acid (2,4-D) was used as a model pesticide and encapsulated into the CMCS-DEACMS micelles. In these micelle formulations, the release of 2,4-D was promoted upon simulated sunlight irradiation, during which the coumarin moieties were cleaved from the CMCS backbone, resulting in a shift of the hydrophilic–hydrophobic balance and destabilization of the micelles. Additionally, bioassay studies suggested that this 2,4-D contained which micelles showed good bioactivity on the target plant without harming the nontarget plant. Thereby, the light-responsive CMCS-DEACMS micelles bearing photocleavable coumarin moieties provide a smart delivery platform for agrochemicals.Keywords:carboxymethyl chitosan micelles;light-responsive;coumarin;2,4-D;controlled release;pesticide
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