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Huang Q, Cai Y, Zhang X, Liu J, Liu Z, Li B, Wong H, Xu F, Sheng L, Sun D, Qin J, Luo Z, Lu X. Aligned Graphene Mesh-Supported Double Network Natural Hydrogel Conduit Loaded with Netrin-1 for Peripheral Nerve Regeneration. ACS APPLIED MATERIALS & INTERFACES 2021; 13:112-122. [PMID: 33397079 DOI: 10.1021/acsami.0c16391] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The gold standard treatment for peripheral nerve injuries (PNIs) is the autologous graft, while it is associated with the shortage of donors and results in major complications. In the present study, we engineer a graphene mesh-supported double-network (DN) hydrogel scaffold, loaded with netrin-1. Natural alginate and gelatin-methacryloyl entangled hydrogel that is synthesized via fast exchange of ions and ultraviolet irradiation provide proper mechanical strength and excellent biocompatibility and can also serve as a reservoir for netrin-1. Meanwhile, the graphene mesh can promote the proliferation of Schwann cells and guide their alignments. This approach allows scaffolds to have an acceptable Young's modulus of 725.8 ± 46.52 kPa, matching with peripheral nerves, as well as a satisfactory electrical conductivity of 6.8 ± 0.85 S/m. In addition, netrin-1 plays a dual role in directing axon pathfinding and neuronal migration that optimizes the tube formation ability at a concentration of 100 ng/mL. This netrin-1-loaded graphene mesh tube/DN hydrogel nerve scaffold can significantly promote the regeneration of peripheral nerves and the restoration of denervated muscle, which is even superior to autologous grafts. Our findings may provide an effective therapeutic strategy for PNI patients that can replace the scarce autologous graft.
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Affiliation(s)
- Qun Huang
- Department of Vascular Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Yuting Cai
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China
- Department of Chemical and Biological Engineering, and William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon 999077, Hong Kong, China
| | - Xing Zhang
- Department of Vascular Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Junchao Liu
- Department of Vascular Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Zhenjing Liu
- Department of Chemical and Biological Engineering, and William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon 999077, Hong Kong, China
| | - Bo Li
- Department of Vascular Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Hoilun Wong
- Department of Chemical and Biological Engineering, and William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon 999077, Hong Kong, China
| | - Feng Xu
- Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, China
| | - Liyuan Sheng
- Shenzhen Institute, Peking University, Shenzhen 518057, China
| | - Dazhi Sun
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China
| | - Jinbao Qin
- Department of Vascular Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
- Vascular Center of Shanghai Jiao Tong University, Shanghai 200011, China
| | - Zhengtang Luo
- Department of Chemical and Biological Engineering, and William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon 999077, Hong Kong, China
| | - Xinwu Lu
- Department of Vascular Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
- Vascular Center of Shanghai Jiao Tong University, Shanghai 200011, China
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Fan N, Guo J, Jing G, Liu C, Wang Q, Wu G, Jiang H, Peng B. A hillock-like phenomenon with low friction and adhesion on a graphene surface induced by relative sliding at the interface of graphene and the SiO 2 substrate using an AFM tip. NANOSCALE ADVANCES 2020; 2:2548-2557. [PMID: 36133360 PMCID: PMC9418518 DOI: 10.1039/c9na00660e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 03/29/2020] [Indexed: 06/16/2023]
Abstract
Graphene demonstrates high potential as an atomically thin solid lubricant for sliding interfaces in industry. However, graphene as a coating material does not always exhibit strong adhesion to any substrates. When the adhesion of graphene to its substrate weakens, it remains unknown whether relative sliding at the interface exists and how the tribological properties of the graphene coating changes. In this work, we first designed a method to weaken the adhesion between graphene and its SiO2 substrate. Then the graphene with weakened adhesion to its substrate was rubbed using an AFM tip, where we found a novel phenomenon: the monolayer graphene not only no longer protected the SiO2 substrate from deformation and damage, but also prompted the formation of hillock-like structures with heights of approximately tens of nanometers. Moreover, the surface of the hillock-like structure exhibited very low adhesion and a continuously decreasing friction force versus sliding time. Comparing the hillock-like structure on the bare SiO2 surface and the proposed force model, we demonstrated that the emergence of the hillock-like structure (with very low adhesion and continuously decreasing friction) was ascribed to the relative sliding at the graphene/substrate interface caused by the mechanical shear of the AFM tip. Our findings reveal a potential failure of the graphene coating when the adhesion strength between graphene and its substrate is damaged or weakened and provide a possibility for in situ fabrication of a low friction and adhesion micro/nanostructure on a SiO2/graphene surface.
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Affiliation(s)
- Na Fan
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China Chengdu 611731 China
| | - Jian Guo
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China Chengdu 611731 China
- School of Mechanical Engineering, University of South China Hengyang 421001 China
| | - Guangyin Jing
- National Key Laboratory and Incubation Base of Photoelectric Technology and Functional Materials, School of Physics, Northwest University Xi'an 710069 China
| | - Cheng Liu
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China Chengdu 611731 China
| | - Qun Wang
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China Chengdu 611731 China
| | - Guiyong Wu
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China Chengdu 611731 China
| | - Hai Jiang
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China Chengdu 611731 China
| | - Bei Peng
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China Chengdu 611731 China
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A New Approach of Mathematical Analysis of Structure of Graphene as a Potential Material for Composites. MATERIALS 2019; 12:ma12233918. [PMID: 31783513 PMCID: PMC6926717 DOI: 10.3390/ma12233918] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 11/16/2019] [Accepted: 11/22/2019] [Indexed: 11/26/2022]
Abstract
The new analysis of a simplified plane model of single-layered graphene is presented in this work as a potential material for reinforcement in ultralight and durable composites. However, owing to the clear literature discrepancies regarding the mechanical properties of graphene, it is extremely difficult to conduct any numerical analysis to design parts of machines and devices made of composites. Therefore, it is necessary to first systemize the analytical and finite element method (FEM) calculations, which will synergize mathematical models, used in the analysis of mechanical properties of graphene sheets, with the very nature of the chemical bond. For this reason, the considered model is a hexagonal mesh simulating the bonds between carbon atoms in graphene. The determination of mechanical properties of graphene was solved using the superposition method and finite element method. The calculation of the graphene tension was performed for two main directions of the graphene arrangement: armchair and zigzag. The computed results were verified and referred to articles and papers in the accessible literature. It was stated that in unloaded flake of graphene, the equilibrium of forces exists; however, owing to changes of inter-atom distance, the inner forces occur, which are responsible for the appearance of strains.
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Gao Y, Xu B. van der Waals Graphene Kirigami Heterostructure for Strain-Controlled Thermal Transparency. ACS NANO 2018; 12:11254-11262. [PMID: 30427663 DOI: 10.1021/acsnano.8b05868] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Programming thermal transport across interfaces by engineering strain is of critical importance for exploring mechanical controllable and thermal manageable devices with multifunctionalities. Here, we report a van der Waals heterostructure that is composed of bilayer graphene kirigami with diverse layer cut patterns and assembly organizations and show that the thermal flow intensity across the van der Waals interfaces, named as thermal transparency, could be continuously regulated by applying an external in-plane tensile strain. The density of atomic interactions across the interfaces and the distribution of delocalized phonon modes in each graphene kirigami are elucidated to understand the underlying thermal transport mechanism and are also incorporated into a theoretical model for quantitative predictions of thermal conductance under mechanical strain. A proof-of-conceptual van der Waals graphene kirigami heterostructure by design is proposed and validated through extensive full-scale atomistic simulations on the feasibility and reliability of regulating the transparency ratio of thermal transport by mechanical strain, demonstrating its potential applications in thermal and electronic devices.
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Affiliation(s)
- Yuan Gao
- Department of Mechanical and Aerospace Engineering , University of Virginia , Charlottesville , Virginia 22904 , United States
| | - Baoxing Xu
- Department of Mechanical and Aerospace Engineering , University of Virginia , Charlottesville , Virginia 22904 , United States
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Liu Y, Liu Y, Luo J. Atomic Scale Simulation on the Fracture Mechanism of Black Phosphorus Monolayer under Indentation. NANOMATERIALS 2018; 8:nano8090682. [PMID: 30200416 PMCID: PMC6163899 DOI: 10.3390/nano8090682] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 11/16/2022]
Abstract
Molecular dynamics simulations on the indentation process of freestanding and Pt(111)-supported black phosphorus (BP) monolayer were conducted to study the fracture mechanism of the membrane. For the freestanding BP monolayer, crack grows firstly along armchair direction and then zigzag direction during the indentation process. Whereas, for the Pt(111)-supported BP monolayer, crack growth shows no obvious directionality, with irregular distribution of crack tips. Further study on stress distribution shows that maximum normal stress component at elastic stage is in zigzag direction for the freestanding BP monolayer, and in vertical direction for the Pt(111)-supported BP monolayer. As BP monolayer is remarkably anisotropic for in-plane mechanical properties and homogeneous for out-of-plane mechanical properties, the difference of stress state may be a key reason for the different fracture behavior in these two cases. These findings may help to understand the failure mechanism of BP, when applied in nano-devices.
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Affiliation(s)
- Yang Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China.
| | - Yuhong Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China.
| | - Jianbin Luo
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China.
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Fan N, Jiang H, Ye Z, Wu G, Kang Y, Wang Q, Ran X, Guo J, Zhang G, Wang G, Peng B. The Insertion Mechanism of a Living Cell Determined by the Stress Segmentation Effect of the Cell Membrane during the Tip-Cell Interaction. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1703868. [PMID: 29717805 DOI: 10.1002/smll.201703868] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 03/11/2018] [Indexed: 06/08/2023]
Abstract
Atomic force microscopy probes are proved to be powerful tools to measure and manipulate the individual cell, providing potential applications for the controlled drug/protein delivery. However, the measured insertion efficiency varies dramatically from 20 to 80%, in some cases, the nanotip can never penetrate the cell membrane no matter how much force is applied to it. Thus, the insertion mechanism of a living cell during the tip-cell interaction must be thoroughly investigated before this technology comes into practical applications. In this work, a multistructural cell model is established to study the tip-membrane interaction. The simulation results show that the stress of the cell membrane can be divided into two stages by the stress segmentation point S. After point S, the stress of the cell membrane increases slightly and most of the indentation force is allocated to the cytoskeleton. This phenomenon is called "stress segmentation effect of the cell membrane," which confirms the hypothesis based on the experimental studies. Moreover, according to the experimental and numerical studies, the hypothesis of the stress segmentation effect also explains the reason that modifying the cell membrane or using the manmade sharpened nanotip can increase the insertion efficiency.
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Affiliation(s)
- Na Fan
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, P. R. China
| | - Hai Jiang
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, P. R. China
| | - Zhiyi Ye
- Key Laboratory of Biorheological Science and Technology of Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, P. R. China
| | - Guiyong Wu
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, P. R. China
| | - Yuejun Kang
- Institute for Clean Energy & Advanced Materials, Southwest University, Chongqing, 400715, P. R. China
| | - Qun Wang
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, P. R. China
| | - Xiaolin Ran
- Key Laboratory of Biorheological Science and Technology of Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, P. R. China
| | - Jian Guo
- School of Mechanical Engineering, University of South China, Hengyang, Hunan, 421001, P. R. China
| | - Guocheng Zhang
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, P. R. China
| | - Guixue Wang
- Key Laboratory of Biorheological Science and Technology of Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, P. R. China
| | - Bei Peng
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, P. R. China
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Hossain MZ, Hao T, Silverman B. Stillinger-Weber potential for elastic and fracture properties in graphene and carbon nanotubes. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:055901. [PMID: 29271354 DOI: 10.1088/1361-648x/aaa3cc] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This paper presents a new framework for determining the Stillinger-Weber (SW) potential parameters for modeling fracture in graphene and carbon nanotubes. In addition to fitting the equilibrium material properties, the approach allows fitting the potential to the forcing behavior as well as the mechanical strength of the solid, without requiring ad hoc modification of the nearest-neighbor interactions for avoiding artificial stiffening of the lattice at larger deformation. Consistent with the first-principles results, the potential shows the Young's modulus of graphene to be isotropic under symmetry-preserving and symmetry-breaking deformation conditions. It also shows the Young's modulus of carbon nanotubes to be diameter-dependent under symmetry-breaking loading conditions. The potential addresses the key deficiency of existing empirical potentials in reproducing experimentally observed glass-like brittle fracture in graphene and carbon nanotubes. In simulating the entire deformation process leading to fracture, the SW-potential costs several factors less computational time compared to the state-of-the-art interatomic potentials that enables exploration of the fracture processes in large atomistic systems which are inaccessible otherwise.
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Affiliation(s)
- M Z Hossain
- Laboratory of Mechanics and Physics of Heterogeneous Materials, Department of Mechanical Engineering, University of Delaware, Newark, DE 19716, United States of America
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