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Nanofibrous ε-polycaprolactone scaffolds containing Ag-doped magnetite nanoparticles: Physicochemical characterization and biological testing for wound dressing applications in vitro and in vivo

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Bioactive Materials 2021年第7期6卷 2070-2088页

作者： M.K.Ahmed M.A.Zayed S.I.El-dek Mayssa Abdel Hady Doaa H.El Sherbiny Vuk Uskokovic Faculty of Nanotechnology for Postgraduate studies Cairo UniversityEl-Sheikh Zayed 12588Egypt Department of Physics Faculty of ScienceSuez UniversitySuez 43518Egypt Chemistry Department Faculty of ScienceCairo University12613GizaEgypt Materials Science and Nanotechnology Department Faculty of Postgraduate Studies for Advanced SciencesBeni-Suef UniversityBeni SuefEgypt Pharmaceutical Technology Department National Research CentreDokiiGizaEgypt Advanced Materials and Nanobiotechnology Laboratory TardigradeNano LLCIrvineCA92604USA Department of Biochemistry Faculty of DentistryModern University for Technology and InformationMokattamCairoEgypt

Skin wounds can lead to numerous complications with dangerous health consequences.In this work,magnetite nanoparticles were doped with different concentrations of antimicrobial silver(Ag)ions and incorporated into the electrospun nanofibrous ε-polycaprolactone(PCL)scaffolds.Nanoparticles and scaffolds with various Ag contents were characterized using a range of physicochemical techniques.Ag entered magnetite as cations and preferentially positioned at tetrahedral sites,introducing lattice distortions and topographic irregularities.Amorphization of the structure due to accommodation of Ag expanded the lattice in the bulk and contracted it on the surface,where broadened distribution of Fe-O coordinations was detected.Promoting spin canting and diminishing the double exchange interaction through altered distribution of ferric and ferrous ions,Ag softened the magnetism of magnetite.By making the nanoparticle structure more defective,Ag modified the interface with the polymer and promoted the protrusion of the nanoparticles from the surface of the polymeric nanofibers,thus increasing their roughness and hydrophilicity,with positive repercussions on cell adhesion and growth.Both the viability of human melanocytes and the antibacterial activity against E.coli and S.aureus increased with the concentration of Ag in the magnetite phase of the scaffolds.Skin wound healing rate in rats also increased in direct proportion with the concentration of Ag in the magnetite phase,and no abnormalities in the dermal and epidermal tissues were visible on day 10 in the treatment group.These results imply an excellent potential of these composite nanofibrous scaffolds for use as wound dressings and in other reconstructive skin therapies.

关键词： Tissue engineering Wound healing Skin Magnetic nanoparticles nanofiber

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Electrospun nanofibers Withstandable to High-Temperature Reactions: Synergistic Effect of Polymer Relaxation and Solvent Removal

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Advanced Fiber Materials 2021年第1期3卷 14-25页

作者： Guofang Hu Xiaohua Zhang Xiaoyan Liu Jianyong Yu Bin Ding College of Textile and Innovation Center for Textile Science and Technology Donghua UniversityShanghai 201620China

Fiber breakage is found to be a ubiquitous phenomenon during the thermal treatments for electrospun nanofibers,because of the presence of solvent molecules and unrelaxed assembly of polymer chains.Here a strengthening strategy is designed by introducing a pre-heating stage for the as-spun nanofibers.At a temperature above the polymer’s glass transition temperature,the chains can get sufficiently relaxed by the aid of hot solvent,and at the same time,the solvent confined in the entangled chains can fully and steadily evaporate,but not erupt,off the nanofiber,when the temperature is just as high as the boiling point.Therefore,the nanofibers become more uniform in structure and can withstand the subsequent thermal reactions.For polyacrylonitrile-based electrospinning,such strategy can improve the final tensile strength from 42 to 112 MPa for the nanofiber films.

关键词： Polyacrylonitrile nanofiber Electrospinning Polymer relaxation Solvent Removal Strengthening

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Development of a Tactile and Slip Sensor with a Biomimetic Structure-enhanced Sensing Mechanism

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Journal of Bionic Engineering 2019年第1期16卷 47-55页

作者： Yonggang Jiang Zhiqiang Ma Bonan Cao Longlong Gong Lin Feng Deyuan Zhang School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China International Research Institute for Multidisciplinary Science Beihang UniversityBeijing 100191China

Tactile and slip sensors have gained tremendous attention for their promising applications in the fields of smart robotics,implantable medical devices and minimally invasive surgery.Inspired by the structure-enhanced sensing mechanisms of human fingertips and tree frog toes,we developed a tactile and slip sensor by combining biomimetic surface microstructures with highly sensitive P(VDF-TrFE)nanofiber sensors on a flexible polyimide substrate.As the surface microstructures could mediate the micro-vibration induced by slip motion,the frequencies of output signals revealed a strong correlation with the periods of microstructures.In addition,we proposed a method to discriminate touch force from slip motion using the criterion of standard deviation of time delay from the output signals of neighboring sensor elements.

关键词： tactile sensor slip detection nanofiber microstructure biomimetic sensing

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Microporous carbon nanofibers prepared by combining electrospinning and phase separation methods for supercapacitor

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Journal of Energy Chemistry 2016年第4期25卷 587-593页

作者： Chang Liu Yongtao Tan Ying Liu Kuiwen Shen Bowu Peng Xiaoqin Niu Fen Ran School of Material Science and Engineering Lanzhou University of Technology State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals Lanzhou University of Technology

Microporous carbon nanofibers (MCNFs) derived from polyacrylonitrile nanofibers were fabricated via electrospinning technology and phase separation in the presence of polyvinylpyrrolidone (PVP). PVP together with a mixed solvent of N, N-Dimethylformamide and dimethyl sulfoxide was used as pore forming agent. The influences of PVP content in casting solution on the structure and electrochemical performance of the MCNFs were also investigated. The highest capacitance of 200 F/g was obtained on a three-electrode system at a scan rate of 0.5 A/g. The good performance was owing to the high specific surface area and the large amount of micro-pores, which enhanced the absorption and the transportation efficiency of electrolyte ion during charge/discharge process. This research indicated that the combination of electrospinning and phase separation technology could be used to fabricate microporous carbon nanofibers as electrode materials for supercapacitors with high specific surface area and outstanding electrochemical performance. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.

关键词： Supercapacitor Electrospinning nanofiber Phase separation

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Force Spectrum of Single CsgA nanofiber Reveal Surprising Properties

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医用生物力学 2019年第A1期34卷 181-181页

作者： Jingqi Lv Yingfeng Li Kai Zhou Pei Guo Ke Ding Quan Long Yang Liu Qi Wang Chao Zhong Botao Xiao School of Biology and Biological Engineering South China University of Technology School of Physical Science and Technology Shanghaitech University Sci-tech Industrial Park Guangzhou University of Traditional Chinese Medicine Co.Ltd. Department of Physics and Astronomy Northwestern University

CsgA protein monomers consist of aβ-helix of five repeat units possessing several conservative residues and thus,inherently fibrillate.CsgA protein monomers could self-assemble into hierarchical nanofiber structure cross multiple scales after expression and secretion by E.Coli cells.Previous researches show that CsgA nanofibers could provide adhesion,stiffness,and mechanical homogeneity for the biofilms,host cells’fibronectin binding for internalization,or protection against phage attack.CsgA nanofibers have obtained various applications in material science and synthetic biology.To illustrate,CsgA nanofibers have characteristics of intrinsic hierarchical structures across multiple scales,robustness in harsh environments and programmable functionality via biological tools.Studying the force spectrum or mechanical properties of the nanofiber can provide fundamental information of self-assembly process and ultra-stability in extreme conditions.Single molecule techniques such as atomic force microscopy,optical tweezers,and magnetic tweezers have been widely applied to study proteins.In these studies,proteins are usually chemically conjugated or genetically constructed to have a tag such as histidine,cysteine or biotin.Genetic engineering requires modification of the plasmids encoding the specific protein,and also involve special protein expression and purification.Such study needs collaboration from multi-disciplinary.It normally studies one protein at a time which gives out clear signal but lacks throughput and efficiency.Here we have established a simple method to measure all kinds of proteins without labels.The carboxyl terminus of a protein is attached to the amine group on a magnetic bead,and the amine terminus of the protein is attached to glutaraldehyde on the glass slide.Then we used magnetic tweezers to manipulate and stretched the bead and protein.Extension versus rotation relation was used to identify a single protein or protein fibril.The fiber under tension is also observed by Scanning Electronic Microco

关键词： Force Spectrum of Single CsgA nanofiber Reveal Surprising Properties

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Impregnation of carbonaceous nanofibers into glassy polymer-based composite membrane for CO_2 separation

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Chinese Journal of Chemical Engineering 2018年第11期26卷 2385-2390页

作者： Pannir Selvam Murugiah Pei Ching Oh Kok Keong Lau CO_2 Research Centre Institute of Contaminant ManagementChemical Engineering DepartmentUniversiti Teknologi PETRONAS

The development of defect-free composite membrane(CM) is often challenging due to poor dispersion and distribution of filler particles in the polymer matrix. Despite the attractive physicochemical properties and gas separation performance of carbon nanotube(CNT) based CM, CNT displayed poor dispersion characteristics in most polymer matrix domain. Instead of incorporating CNT, a viable alternative, carbon nanofiber(CNF) which exhibits similar properties as CNT, but improved dispersion quality in the polymer matrix is found. In this work,CNF particles were incorporated in poly(2,6-dimethyl-1,4-phenylene oxide)(PPOdm) polymer continuous phase for CM development. The optimum gas separation performance of the PPOdm-CNF CM(11.25 at 197.02 barrer of CO_2 permeability) was obtained at 3 wt% of CNF loading. Compared to pristine PPOdmmembrane,CO_2 permeability and CO_2/CH_4 selectivity of PPOdm-3 wt% CNF CM were enhanced by 180% and 55%, respectively.At 3 wt% CNF loading, the filler particles were dispersed and distributed more homogenously, in which no obvious CNF agglomeration was observed. In addition, the incorporation of CNF particles also enhanced the mechanical and thermal properties of the resultant CM.

关键词： Carbon nanofiber Composite membrane Carbon dioxide Gas separation

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Advances on ultra-sensitive electrospun nanostructured electrochemical and colori metric sensors for diabetes mellitus detection

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Nano Materials Science 2021年第4期3卷 321-343页

作者： Mohamed Hasaan Hussain Lim Ping Fook Maria Kana Sanira Putri Huey Ling Tan Noor Fitrah Abu Bakar Norbert Radacsi School of Chemical Bngineering College of Engineering University Teknologi MARA 40450 Shah AlamSelangorMalaysia School of Engineering Institute for Materials and ProcessesThe University of EdinburghRobert Stevenson RoadEdinburghEH93FBUnited Kingdom

Recent developments in the biochemical and medicinal industries have been heavily focused on producing affordable glucose biosensors due to the condi nuous annual increase of diabetic patients worldwide.The devel-opment of a fast,accurate,and reliable glucose sensor will increase confidence in controlling di abetes mellitus and its assoclated health complications among the diabetic community.Electraspinning is a versatile method that can produce complex nanofbrous assemblies with attractiwe and functional characteristics from varlous polymers.Electrospun nanofibers demonstrated high efficiency in the immobilization of biological molecules,which can improve the sensing performance further.Integr ation of polymer electrospun nanofibers with metal nanoparticles,metal oxde or transition metal in producing nanobiocomposites is also a highly popul ar approach in the past few years.This report presents the current progress and research trends of the technique,focusing on varous ma-terials and fabrication strategies used to produce biosensing interfaces.This helps readers decide the suitable approach in designing highly sensitive,selective,fast,and inexpensive glucose sensors.

关键词： Glucose sensor Electrospinning nanofiber Electrochemical sensing Colorimetric sensing

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Hydrothermal synthesis of manganese oxide encapsulated multiporous carbon nanofibers for supercapacitors

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Nano Research 2016年第9期9卷 2672-2680页

作者： Haiyan Wang Jiang Deng Yiqing Chen Fan Xu Zhongzhe Wei Yong Wang Advanced Materials and Catalysis Group ZJU-NHU United R&D CenterCenter for Chemistry of High-Performance and Novel MaterialsDepartment of ChemistryZhejiang UniversityHangzhou 310028China

Hydrothermal carbonization (HTC) of biomass to produce one-dimensional carbon materials with hierarchical pores is of significant importance. Here, we fabricate composites of MnOx-encapsulated multiporous carbon nanofibers (M-MCNFs) from naturally available carbohydrates through a dopamine-assisted HTC/ templating process. The introduction of dopamine aids in the formation of the morphology of carbon nanofibers (CNFs) by enhancing the interactions between the hard-templates and carbohydrates. The chosen cryptomelane hard-templates, which are superior to traditional hard-templates, are converted into Mn3O4 nanoparticles embedded in multiporous CNFs (MCNFs), eliminating the need for tedious post deposition procedures to introduce redox active sites. Hence, the obtained hybrids with large surface areas, hierarchical pores, and unique structures show great potential in supercapacitors. This economic and sustainable strategy paves a new way for synthesizing MCNFs and metal oxide-encapsulated MCNFs composites from biomass.

关键词： hydrothermal carbonization multiporous carbon nanofiber manganese oxide encapsulated supercapacitor

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Improved formaldehyde gas sensing properties of well-controlled Au nanoparticle-decorated In2O3 nanofibers integrated on low power MEMS platform

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Journal of Materials Science & Technology 2020年第3期38卷 56-63页

作者： Dongha Im Donghyun Kim Dasol Jeong Woon Ik Park Myoungpyo Chun Joon-Shik Park Hyunjung Kim Hyunsung Jung Nano Materials&Nano Technology Center Korea Institute of Ceramic Engineering&TechnologyJinju 52851Republic of Korea Department of Mineral Resources and Energy Engineering Chonbuk National UniversityJeonju 54896Republic of Korea Smart Sensor Research Center Korea Electronic Technology InstituteSeongnam 13509Republic of Korea

Approaches for the fabrication of a low power-operable formaldehyde(HCHO)gas sensor with high sensitivity and selectivity were performed by the utilization of an effective micro-structured platform with a micro-heater to reach high temperature with low heating power as well as by the integration of indium oxide(In2O3)nanofibers decorated with well-dispersed Au nanoparticles as a sensing material.Homogeneous In2O3 nanofibers with the large specific surface area were prepared by the electrospinning following by calcination process.Au nanoparticles with the well-controlled size as a catalyst were synthesized on the surface of In2O3 nanofibers.The Au-decorated In2O3 nanofibers were reliably integrated as sensing materials on the bridge-type micro-platform including micro-heaters and micro-electrodes.The micro-platform designed to maintain high temperature with low power consumption was fabricated by a microelectromechanical system(MEMS)technique.The micro-platform gas sensor consisting with Au-In2O3 nanofibers were fabricated effectively to detect HCHO gases with high sensitivity and selectivity.The HCHO gas sensing behaviors were schematically studied as a function of the gas concentration,the size of the adsorbed Au nanoparticles,the applied power to raise the temperature of a sensing part and the kind of target gases.

关键词： Gold nanoparticle In2O3 nanofiber Formaldehyde Gas sensor Low power Micro-platform

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Cobalt monosulfide nanofibers:ethanol sensing and magnetic properties

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Rare Metals 2021年第6期40卷 1554-1560页

作者： Zhi-Da Hu Xi-Yu Sun Hang-Fei Li Ya-Ru Kang Xian-Qiang Song Peng Wang Qiao-Tong Luan Xue-Dong Wang Zong-Tao Chi Wan-Feng Xie School of Electronics and Information Qingdao UniversityQingdao 266071China Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices Institute of Functional Nano and Soft Materials(FUNSOM)Soochow UniversitySuzhou 215123China School of Material Science and Engineering Qingdao UniversityQingdao 266071China State Key Laboratory of Bio-Fibers and Eco-Textiles Qingdao UniversityQingdao 266071China

Metal sulfide nanomaterials have attracted great interest because of their excellent properties and promising applications in sensing,energy harvesting,magnetic and optoelectronic devices,especially their well-aligned crystalline nanostructures are highly desirable for the enhanced performance and novel applications.In this study,the cobalt monosulfide(CoS)nanofibers with uniform shape and good crystallinity were firstly obtained via electrospinning and atmospheric calcination routes under controllable conditions.It was found that the CoS nanofibers exhibited ethanol sensing properties at the optimum working temperature of 200℃,the response was 11.6 toward 100×10^(-6) ethanol gas,and the CoS nanofibersbased sensor exhibits a short response time and recovery time of 5 and 6 s at the optimum temperature,respectively,the result also shows that the sensor has good stability after 50 days,which would be a favorable characteristic as a promising sensor.In addition,the Pauli paramagnetic property of CoS nanofibers was also investigated at room temperature.

关键词： Electrospinning nanofiber CoS Ethanol sensing Paramagnetic

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