Biomedical Materials
·
2014
·Vol. 9
·期 1
·015007
·
IF 2.922
Qi Wang,Pei Liu,Peifeng Liu,Tao Gong,Suming Li,Yourong Duan,Zhirong Zhang
Biodegradable chitosan-graft-polylactide (PLA–CS) copolymers were prepared by the grafting of a poly(L-lactide) (PLLA) or poly(D-lactide) (PDLA) precursor to the backbone of chitosan using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC ⋅ HCl) and N-hydroxysuccinimide (NHS) as a coupling agent. The blood and cell compatibility of the graft copolymers were investigated in comparison to PLLA and PDLA homopolymers. The coagulation properties of PLA–CS were evaluated by hemolysis, plasma recalcification, dynamic blood clotting and protein absorption assays. PLA–CS copolymers present similar hemolysis ratio and plasma recalcification time as PLA, but slower dynamic blood clotting and lower protein absorption. The cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), agar diffusion and lactate dehydrogenase (LDH) experiments. All the samples presented no effect on the viability to cells. Inflammatory cytokine analysis using sandwich ELISAs revealed that PLA–CS would not stimulate inflammatory activity.
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高影响因子
MOLECULAR PHARMACEUTICS
·
2013
·
IF 4.57
Yuanyuan Guo,Min Chu,Songwei Tan,Shuang Zhao,Hanxiao Liu,Ben Oketch Otieno,Xiangliang Yang,Chuanrui Xu,Zhiping Zhang
To overcome the P-glycoprotein (P-gp)-induced multidrug resistance (MDR) of cancer cells, a novel copolymer, chitosan-graft-d-α-tocopheryl polyethylene glycol 1000 (TPGS) (CT) was synthesized for doxorubicin (DOX) delivery by the P-gp inhibiting virtue of TPGS. DOX-loaded CT nanoparticles (NPs) were fabricated by a modified solvent extraction/evaporation method combined with ionic cross-linking to form a uniform particle size of 140–180 nm with ∼40% DOX loading efficiency. These drug-loaded CT NPs demonstrated a pH-responsive release behavior, and DOX was released more quickly under low pH values. Significant cell cytotoxicity was observed on the human hepatocarcinoma cells (HepG2 and BEL-7402) and human breast adenocarcinoma cells (MCF-7). The cell cytotoxicity and apoptosis of drug-resistant cells (MCF-7/DOX and BEL-7402/5-Fu), was greatly enhanced as compared to Adriamycin. The IC50 value showed that DOX-loaded CT NPs could be 1.5–199-fold more effective than Adriamycin. This can be attributed to the P-gp blocking and down-regulation of ATP levels by the CT NPs. The potential of these NPs to act as an oral delivery system was also investigated. Both the pharmacokinetic properties and in vivo antitumor activity of DOX-loaded CT NPs were improved compared with Adriamycin.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2014
·
IF 3.096
Rui Zhao,Xiang Li,Bolun Sun,Ying Zhang,Dawei Zhang,Zhaohui Tang,Xuesi Chen,Ce Wang
Chitosan and sericin are natural and low cost biomaterials. Both biomaterials displayed good compatibility to human tissues and antibacterial properties for biomedical application. In this study, we have successfully fabricated chitosan/sericin composite nanofibers by electrospinning. The obtained composite nanofibers were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) studies. The composite nanofibers had good morphology with diameter between 240 nm and 380 nm. In vitro methyl thiazolyl tetrazolium (MTT) assays demonstrated that the chitosan/sericin composite nanofibers were biocompatible and could promote the cell proliferation . Furthermore, the composite nanofibers showed good bactericidal activity against both of Gram-positive and Gram-negative bacteria. Thus, the chitosan/sericin composite nanofibers are promising for wound dressing applications.
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VACCINE
·
2014
·
IF 3.485
Qingfeng Liu,Chi Zhang,Xiaoyao Zheng,Xiayan Shao,Xi Zhang,Qizhi Zhang,Xinguo Jiang
The frequent outbreak of respiratory infectious diseases such as influenza and pulmonary tuberculosis calls for new immunization strategies with high effectiveness. Nasal immunization is one of the most potential methods to prevent the diseases infected through the respiratory tract. In this study, we designed a water-soluble system based on antigen/ N -trimethylaminoethylmethacrylate chitosan conjugates for nasal immunization. N -trimethylaminoethylmethacrylate chitosan (TMC) was synthesized by free radical polymerization of chitosan and N -trimethylaminoethylmethacrylate chloride and identified by 1 H NMR and FT-IR. Thiolated ovalbumin (OVA) was covalently conjugated to maleimide modified TMC with high conjugation efficiency. OVA conjugated TMC (OVA–TMC) significantly increased uptake of OVA by Raw 264.7 cells, which was 2.38 times higher than that of OVA/TMC physical mixture (OVA + TMC) at 4 h. After nasal administration, OVA–TMC showed higher transport efficiency to superficial and deep cervical lymph nodes than OVA + TMC or OVA alone. Balb/ C mice were intranasally given with OVA–TMC three times at 2-week internals to evaluate the immunological effect. The serum IgG, IgG1 and IgG2a levels of the OVA–TMC group were 17.9–87.9 times higher than that of the OVA + TMC group and comparable to that of the intramuscular group. The secretory IgA levels in nasal wash and saliva of the OVA–TMC group were 5.2–7.1 times higher than that of the OVA + TMC group while the secretory IgA levels of the intramuscular alum-precipitated OVA group were not increased. After immunofluorescence staining of nasal cavity, IgA antibody secreting cells were mainly observed in the lamina propria regions and glands of nasal mucosa. OVA–TMC showed little toxicity to the nasal epithelia or cilia of rats after nasal administration for three consecutive days. These results demonstrated that antigen conjugated TMC can induce both systemic and mucosal immune responses after nasal administration and may serve as a convenient, safe and effective vaccine for preventing respiratory infectious diseases.
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JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2013
·Vol. 28
·期 3
·617-621
·
IF 0.484
Zeng Rong,Wang Zehu,Wang Hongran,Chen Liqiang,Qiao Renzhong,Hu Liming,Li Zelin
Chitosan-stavudine (d4T) conjugate with a succinic spacer was synthesized via carbodiimide coupling reaction and structurally characterized. In order to nanosize it for improving its therapeutic properties, the chitosan-5′- O -succinyl-d4T conjugate was crosslinked with sodium tripolyphosphate (TPP) to obtain the chitosan-d4T conjugate nano-prodrug. The morphologies of chitosan-d4T conjugate nanoparticles were observed by transmission electron microscopy (TEM), and their zeta potential, particle size, and polydispersity (size distribution) were measured by the dynamic light scattering (DLS) techniques. In vitro drug release studies at pH 1.1 and pH 7.4 indicate that the crosslinked chitosan-d4T conjugate nano-prodrug can prevent the coupled d4T from leaking out before entering the target viral reservoirs and provide a mild sustained release without the burst release. The results reveal that constructing conjugated chitosan nano-prodrugs may be a promising approach for improving the therapy efficacy of drugs in antiviral treatment.
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JOURNAL OF NANOPARTICLE RESEARCH
·
2013
·Vol. 15
·期 12
·1-15
·
IF 2.175
Huang Shengtang,Wan Ying,Wang Zheng,Wu Jiliang
Chitosan was conjugated with folic acid (FA) and the resulting chitosan derivatives with a FA-substitution degree of around 6 % was used to synthesize FA-conjugated chitosan–polylactide (FA–CH–PLA) copolymers to build a drug carrier with active targeting characteristics for the anticancer drug of paclitaxel (PTX). Selected FA–CH–PLAs with various polylactide percentages of about 40 wt% or lower were employed to fabricate nanoparticles using sodium tripolyphosphate as a crosslinker, and different types of nanoparticles were endued with similar average particle-sizes located in a range between 100 and 200 nm. Certain types of PTX-loaded FA–CH–PLA nanoparticles having encapsulation efficiency of around 90 % and initial load of about 12 % were able to release PTX in a controlled manner with significant regulation by polylactide content in FA–CH–PLAs. Targeting characteristic of achieved nanoparticles was confirmed using FA-receptor-expressed MCF-7 breast cancer cells. The uptake of PTX revealed that optimized FA–CH–PLA nanoparticles with an equivalent PTX-dose of around 1 μg/mL could have more than sixfold increasing abilities to facilitate intracellular paclitaxel accumulation in MCF-7 cells after 24 h treatment as compared to free PTX. At a relatively safe equivalent PTX-dose for normal MCF-10A mammary epithelial cells, the obtained results from Hoechst 33342 staining indicated that optimized PTX-loaded FA–CH–PLA nanoparticles had more than threefold increasing abilities to induce MCF-7 cell apoptosis in comparison to free PTX.
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Soft Matter
·
2013
·Vol. 9
·期 46
·11136-11142
·
IF 3.909
Jingjun Wu,Qian Zhao,Chengzhen Liang,Tao Xie
Enzyme-degradable hydrogels with aligned pores were prepared via unidirectional freezing of a mixed solution of oxidized dextran (oxDex) and chitosan (CHI) followed by cryo-gelation. At the frozen state, imine bonds as the crosslinking points of the hydrogels were formed as a result of the reaction between the aldehyde groups on the oxDex and the amino groups on the CHI. The morphologies of the obtained hydrogels were studied by confocal laser scanning microscopy (CLSM). Microtubular pores aligned along the freezing direction were obtained in the swollen state of the hydrogels. The pore size was adjustable ranging from 20 to 100 μm by controlling the freezing temperature in the unidirectional freezing step. Upon exposure of the hydrogels to chitosanase solution, chitosan can be hydrolyzed into short oligosaccharide fragments leading to collapse and degradation of the gel network. The degradation rate can be tuned by adjusting the gel composition and enzyme concentration.
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RSC Advances
·
2017
·Vol. 7
·期 20
·12247-12254
·
IF 3.108
Xuan Zhou,Xinshuo Zhang,Jianjun Zhou,Lin Li
6-Deoxy-6-(2-aminoethyl) amino chitosan (CS-AEA) and aminoethyl modified CS-AEA (CS-AEA-AEM) were synthesized and characterized using FTIR, NMR and elemental analysis. The results showed that the expected CS derivatives were obtained, and the amine group content increased successively in CS, CS-AEA and CS-AEA-AEM. The red blood cell (RBC) agglutination behaviors in solutions of CS and its derivatives were studied using optical microscopy (OM) and ultraviolet-visible (UV-Vis) spectrophotometry. The results demonstrated that the agglutination of RBCs became more evident upon decreasing the pH value and increasing the concentration. Although CS-AEA-AEM had the highest content of amine groups, CS-AEA exhibited the best agglutination performance under the pH and concentration range studied. Potentiometric titration and ionization degree calculations showed that the agglutination behavior of RBCs was determined by the number of protonated amines in CS or its derivatives. Hemocompatibility tests showed that the hemolysis of CS derivatives increased after modification, and the CS derivatives could be classified as a slightly hemolytic material. We have sucessfully developed a CS derivative (CS-AEA) with very good RBC agglutination performance under neutral conditions.
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Journal of Materials Chemistry B
·
2015
·Vol. 4
·期 5
·893-901
·
IF 4.726
Fu-xing Lin,Jie-lin Rong,Mo-zhen Wang,Dan-dan Bao,Yun Wang,Zhen-xing Gong,Yu-fang Gu,Yu Zhao,Xue-wu Ge
A core–shell structured chitosan (CS)-based gene vector with a sustainable gene transfection effect was designed and successfully prepared in this study. The pEGFP was first combined with the thiolated and N-alkylated chitosan (TACS). Then, hydroxybutyl chitosan grafted with poly(ethylene glycol) (EG–HBC) was coated on the pEGFP-loaded TACS particles. The prepared pEGFP-loaded TACS@EG–HBC particles have a size of about 200 nm and little cytotoxicity. The in vitro and in vivo gene transfection experiments indicate that the pEGFP-loaded TACS@EG–HBC particles possess a better sustainable gene transfection capacity and a high transfection efficiency, which should be attributed to the biodegradation of the CS-based shell, the thiolation and N-alkylation modification on CS cores, and the grafted PEG chains with better biocompatibility. The in vivo gene expression of the loaded pEGFP can persist up to 60 days. This novel gene vector has a theoretical and practical significance for gene therapy with sustained transfection effect.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 134
·期 29
·45104
·
IF 1.86
Guangyu Wu,Jianguo Huang,Weidong Li
In this study, we proposed an alternative way to produce graphene nanosheet (GNS)/chitosan (CS) composites. Graphite-intercalating compounds (GICs) were prepared by graphite and m -chloroperbenzion acid (M-CPBA) as starting materials. The GNS–CS composites were produced through the mixing of the GICs into CS and the removal of impurities in the final step. X-ray diffraction, atomic force microscopy, and transmission and scanning electron microscopy analyses showed that graphite could be effectively exfoliated by an intercalating agent (M-CPBA) and the GNSs were homogeneously dispersed into the CS matrix. Furthermore, we demonstrated that the electrochemical behavior and mechanical properties of the GNS–CS composites were significantly improved with a low level of GNSs in CS. The redox peak current increased 509%, and the modulus and hardness of the GNS–CS composites increased by 2.7 and 0.15 GPa, respectively, when the GNSs addition was 0.6 wt %. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45104.
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JOURNAL OF POWER SOURCES
·
2025
·
IF 7.9
Huiying Cheng,Jingchang Sun,Siwen Liu,Furong Cao,Liuting Shan,Zijiang Yang,Xiaofan Cui,Jiaxu Zhao,Zhen Qiao,Qiuju Feng
Low-grade heat (<100 °C) is abundant and ubiquitous in the environment, and the recovery of low-grade heat energy will be of great significance for the energy supply and the improvement of the environment. Low-cost and effective technologies for transforming low-grade heat into electricity are urgently needed. Thermocell (TEC) based on REDOX couples has become a promising technology for low-grade heat harvesting due to its advantages of low cost, scalability, and intrinsic high thermopower. To enhance its performance, different types of TECs need to incorporate various additives into the REDOX couples. However, there is currently no identical additive that effectively enhances the performance of both P-type and N-type TECs. In this paper, carboxylated chitosan is used as an identical additive, resulting in an increase in the Seebeck coefficient of P-type and N-type TECs by 115.33 % and 53.25 %, respectively. Furthermore, we introduce a novel sandwich-structured packing technique featuring a configuration of Metal/PET film/Carbon felt (MPC) for TEC. This approach effectively reduces both the cost and weight of the TEC, while the MPC structure further enhances their performance. The TEC can be scaled up to power electrical devices. Our achievement provides an effective strategy for harvesting low-grade heat energy.
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MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Yasi Wang,Jingyuan Deng,Hongjia Liu,Ruilong Ran,Tonghua Zhang,Zhi Li
Developing enzymatic glucose sensors with high stability and excellent sensing performance is beneficial for the diagnosis and real-time monitoring of diabetes. In this study, we developed an enzymatic glucose sensor with the RGO (Reduced Graphene Oxide) /SF (Silk Fibroin) composite membrane as a flexible and conductive substrate, and then PB (Prussian Blue) was deposited on the surface of RGO/SF. To enhance the stability of GOD (Glucose Oxidase) and enzymatic glucose sensor, enzyme-chitosan hydrogel electropolymerized on the PB/RGO/SF electrode surface and at last a Nafion layer was coated on the hydrogel to prevent hydrogel detachment and mitigate the effects of interferent. This developed GOD/PB/RGO/SF sensor exhibits good sensing performance in glucose detection, with a response time of less than 10 s, a sensitivity as high as 230.96 μA mM −1 cm −2 at low concentration, and a linear range of 65.57 μM–10 mM, and it also shows good anti-interference feature and reproducibility, providing the reliable sensing performance for detecting glucose levels in human organisms and drinks. In conclusion, the GOD/PB/RGO/SF flexible sensor developed in this study has good prospects for application in glucose real-time monitoring and flexible sensing device.
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