Antibacterial activity and cytocompatibility of chitooligosaccharide-modified polyurethane membrane via polydopamine adhesive layer

Published Date
Received 25 June 2016, Revised 4 September 2016, Accepted 13 September 2016, Available online 13 September 2016

Author

• Chuang Luo^a, b, 
• Wenjun Liu^a, b, 
• Binghong Luo^a, , , 
• Jinhuan Tian^a, b, 
• Wei Wen^a, b, 
• Mingxian Liu^a, b,
• Changren Zhou^b, , 

• ^a Department of Material Science and Engineering, Jinan University, Guangzhou 510632, PR China
• ^b Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510632, PR China

Highlights

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A unique surface design was developed for PU membrane in this study.

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The hydrophilicity of PU membrane improved when modified with PDOPA and COS.

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COS-modified PU membrane favors NIH-3T3 cells adhesion and proliferation.

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Antibacterial activity of PU membrane increased by modification with COS.

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This study reveals the potential of the COS-coated PU membrane as wound dressings.

Abstract
The aim of this study was to provide a convenient surface modification method for polyurethane (PU) membrane and evaluate its influence on hydrophilicity, antibacterial activity and cell functions, which are the most important factors for wound dressings. For this purpose, chitooligosaccharide (COS) was modified onto the surface of PU membrane based on the self-polymerization of dopamine (DOPA). Surface composition, morphology, hydrophilicity and surface energy of the original and modified PU membranes were characterized. Surface roughness and hydrophilicity of the PU membrane were obviously increased by modified with polydopamine (PDOPA) and COS. Antibacterial experiment against Escherichia coli and Staphylococcus aureus indicated that antibacterial activity of PU membrane increased only slightly by modified with PDOPA, but increased significantly by further modified with COS. Cells culture results revealed that COS-functionalized PU membrane is more beneficial to the adhesion and proliferation of NIH-3T3 cells compared to the original and PDOPA-modified PU membranes.

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Bupleurum chinense polysaccharide inhibit adhesion of human melanoma cells via blocking β1 integrin function

Published Date
Received 4 February 2016, Revised 12 September 2016, Accepted 12 September 2016, Available online 13 September 2016

Author

• Haibin Tong^a, b, 1, , 
• Guiquan Jiang^b, 1, 
• Dake Qi^c, 1, 
• Jingfeng Bi^d, 
• Dan Tian^a, 
• Xingang Guan^a, 
• Sheng Zheng^e, 
• Xin Sun^a, , 

• ^a Jilin Provincial Key Laboratory of Molecular Geriatric Medicine, Life Science Research Center, Beihua University, Jilin 132013, China
• ^b Wood Material Science and Engineering Key Laboratory of Jilin Province, Beihua University, Jilin 132013, China
• ^c Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John’s, NL, Canada
• ^d Research Center for Clinical & Translational Medicine, 302 Hospital, Beijing 100039, China
• ^e School of Chemical Engineering, Northeast Dianli University, Jilin 132012, China

Highlights

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BCP, water-soluble polysaccharide extracted from Bupleurum chinense, inhibited integrin-mediated adhesion of human melanoma A375 cells to fibronectin but had no effects on nonspecific adhesion to poly-l-lysine.

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BCP-treatment reduced β1 integrin ligand affinity and inhibited the adhesion-dependent formation of F-actin stress fibers and focal adhesions.

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The inhibition of BCP on integrin-mediated signaling is probably through its dephosphorylatory effects on focal adhesion kinase (FAK) and paxillin.

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Our current findings indicated that BCP may be a potential therapy for melanoma metastasis due to its inhibitory effects on integrin signaling.

Abstract
Adhesive interaction contributes toward tumor metastasis and the transmembrane glycoprotein receptor, integrin has been recognized to mediate the adhesion to extracellular matrix thus upregulating tumor metastasis. In the current study, we evaluated the anti-adhesive mechanisms of a water-soluble polysaccharide (BCP) extracted from Bupleurum chinense. BCP inhibited integrin-mediated adhesion of human melanoma A375 cells to fibronectin but had no effects on nonspecific adhesion to poly-l-lysine. BCP also reduced β1 integrin ligand affinity for GST-FNIII9-10 proteins. The adhesion-dependent formation of F-actin stress fiber and focal adhesion (FA) was also inhibited by BCP treatment. The inhibition of BCP on integrin-mediated signaling is probably through inhibiting phosphorylation of focal adhesion kinase (FAK) and paxillin. Collectively, our current findings indicated that BCP may be a potential therapy for melanoma metastasis due to its inhibitory effects on integrin function.

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Cellulose nanocrystal/hexadecyltrimethylammonium bromide/silver nanoparticle composite as a catalyst for reduction of 4-nitrophenol

Published date
Received 1 August 2016, Revised 27 August 2016, Accepted 30 August 2016, Available online 13 September 2016

Author

• Xingye An^a, b, 
• Yunduo Long^b, , , 
• Yonghao Ni^a, b, , 

• ^a Tianjin Key Laboratory of Pulp and Paper, Tianjin University of Science and Technology, Tianjin 300457, China
• ^b Department of Chemical Engineering, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3, Canada

Highlights

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CNC/CTAB/Ag nanohybrid catalyst with small size and narrow particle distribution, was synthesized by a facile method.

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The steric barriers and increased charges from CTAB surfactant contributed to the improved Ag NPs stability and dispersity.

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CNC/CTAB/Ag nanohybrid catalyst exhibited an excellent catalytic activity (545 h⁻¹) and pseudo-first order rate constant (1.6 × 10⁻³ s⁻¹) in the reduction of 4-nitrophenol (4-NP) by NaBH₄ to 4-aminophenol (4-AP).

Abstract

The application of metal nanoparticles (NPs) in catalysis has drawn significant research interest, including in their applications to the wastewater treatment. Nanocellulose can be a versatile support/carrier in stabilizing metal NPs catalysts, due to its unique properties. In this paper, hexadecyl-trimethylammonium bromide (CTAB) surfactant-adsorbed cellulose nanocrystals (CNC) was employed as a support for silver nanoparticles (Ag NPs). The obtained CNC/CTAB/Ag nanohybrid composite was characterized by ultraviolet–visible (UV–vis) spectroscopy, transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). The results of the catalytic reaction experiments showed that Ag NPs immobilized on CTAB-adsorbed CNC displayed higher catalytic efficiency towards the reduction of 4-nitrophenol to 4-aminophenol, compared to the control Ag NPs and CNC/Ag samples. The enhanced catalytic performance of Ag NPs was attributed to the improved dispersity and narrow distribution of silver nanoparticles in the catalytic system. This work provides a novel catalyst based on CNC-CTAB stabilized Ag NPs which would have promising applications towards catalytic treatment of wastewater.

Graphical Abstract



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