Mimicking the Mechanical Properties of Cartilage Using Ionic- and Hydrogen-Bond Cross-Linked Hydrogels with a High Equilibrium Water Content above 70%

2021 ◽  
Author(s):  
Ning Ding ◽  
Xiaobo Cai ◽  
Pingping Zhang ◽  
Shunni Dong ◽  
Binyang Du ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bond ◽  
Water Content ◽  
Equilibrium Water Content ◽  
High Equilibrium

Preparation of a photocurable hydrogel with adjustable mechanical properties for 3D printing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yifan Xu ◽  
Xiang Gu ◽  
Qinghua Meng ◽  
Bin Wang ◽  
Jun Fan
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Visible Light ◽  
High Capacity ◽  
3D Printer ◽  
Equilibrium Water Content ◽  
Content Type ◽  
Initiation System ◽  
Cross Linker ◽  
High Equilibrium

Purpose This paper aims to show a series of hydrogels with adjustable mechanical properties, which can be cured quickly with visible light. The hydrogel is prepared conveniently with hydroxyethyl acrylate, cross-linker, gelatin and photoinitiator, and can be printed into certain 3D patterns with the direct ink write (DIW) 3D printer designed and developed by the research group. Design/methodology/approach In this paper, the authors designed a composite sensitization initiation system that is suitable for hydrogels. The concentration of photoinitiator, gelatin and cross-linker was studied to optimize the curing efficiency and adjust the mechanical properties. A DIW 3D printer was designed for the printing of hydrogel. Pre-gel solution was loaded into printer for printing into established models. The models were made and sliced with software. Findings The hydrogels can be cured efficiently with 405-nm visible light. While adding various content of gelatin and cross-linker, the mechanical properties of hydrogels show from soft and fragile (elastic modulus of 121.18 kPa and work of tension of 218.11 kJ·m−3) to rigid and tough (elastic modulus of 505.15 kPa and work of tension of 969.00 kJ·m−3). The hydrogels have high capacity of water absorption. With the DIW 3D printer, pre-gel hydrogel solution can be printed into objects with certain dimension. Originality/value In this work, a composite sensitization initiation system was designed, and fast curing hydrogels with adjustable mechanical properties had been prepared conveniently, which has high equilibrium water content and 3D printability with the DIW 3D printer.

Hydrogels as Antibacterial Biomaterials

2018 ◽  
Vol 24 (8) ◽  
pp. 843-854 ◽  
Author(s):  
Weiguo Xu ◽  
Shujun Dong ◽  
Yuping Han ◽  
Shuqiang Li ◽  
Yang Liu
Keyword(s):  
Mechanical Properties ◽  
Drug Delivery ◽  
Tissue Engineering ◽  
Water Content ◽  
Oxygen Permeability ◽  
Structural Diversity ◽  
High Water ◽  
Clinical Applications ◽  
High Water Content ◽  
Biomedical Field

Hydrogels, as a class of materials for tissue engineering and drug delivery, have high water content and solid-like mechanical properties. Currently, hydrogels with an antibacterial function are a research hotspot in biomedical field. Many advanced antibacterial hydrogels have been developed, each possessing unique qualities, namely high water swellability, high oxygen permeability, improved biocompatibility, ease of loading and releasing drugs and structural diversity. In this article, an overview is provided on the preparation and applications of various antibacterial hydrogels. Furthermore, the prospects in biomedical researches and clinical applications are predicted.

Mechanical Properties with Respect to Water Content of Host–Guest Hydrogels

2021 ◽  
Vol 54 (17) ◽  
pp. 8067-8076 ◽  
Author(s):  
Motofumi Osaki ◽  
Shin Yonei ◽  
Chiharu Ueda ◽  
Ryohei Ikura ◽  
Junsu Park ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Content

Synthesis and characterization of photothermal antibacterial hydrogel with enhanced mechanical properties

2021 ◽  
Author(s):  
Shu bin Li ◽  
Xiao Wang ◽  
Jiang Zhu ◽  
Zhenyu Wang ◽  
Lu Wang
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bond ◽  
Fe3o4 Nanoparticles ◽  
Intermolecular Hydrogen Bond ◽  
Amide Bond ◽  
Synthesis And Characterization

In this work, using carboxyl-modified Fe3O4 nanoparticles as a photothermal agent, combining the chemical amide bond and intermolecular hydrogen bond crosslinking force, a photothermal hydrogel with enhanced mechanical properties was...

Study on mechanical properties and damage evolution of carbonaceous shale under triaxial compression with acoustic emission

2021 ◽  
pp. 105678952199119
Author(s):  
Kai Yang ◽  
Qixiang Yan ◽  
Chuan Zhang ◽  
Wang Wu ◽  
Fei Wan
Keyword(s):  
Mechanical Properties ◽  
Acoustic Emission ◽  
Water Content ◽  
Damage Evolution ◽  
Damage Assessment ◽  
Triaxial Compression ◽  
Confining Pressure ◽  
Damage Variable ◽  
Natural State ◽  
Carbonaceous Shale

To explore the mechanical properties and damage evolution characteristics of carbonaceous shale with different confining pressures and water-bearing conditions, triaxial compression tests accompanied by simultaneous acoustic emission (AE) monitoring were conducted on carbonaceous shale rock specimens. The AE characteristics of carbonaceous shale were investigated, a damage assessment method based on Shannon entropy of AE was further proposed. The results suggest that the mechanical properties of carbonaceous shale intensify with increasing confining pressure and degrade with increasing water content. Moisture in rocks does not only weaken the cohesion but also reduce the internal friction angle of carbonaceous shale. It is observed that AE activities mainly occur in the post-peak stage and the strong AE activities of saturated carbonaceous shale specimens appear at a lower normalized stress level than that of natural-state specimens. The maximum AE counts and AE energy increase with water content while decrease with confining pressure. Both confining pressure and water content induce changes in the proportions of AE dominant frequency bands, but the changes caused by confining pressure are more significant than those caused by water content. The results also indicate that AE entropy can serve as an applicable index for rock damage assessment. The damage evolution process of carbonaceous shale can be divided into two main stages, including the stable damage development stage and the damage acceleration stage. The damage variable increases slowly accompanied by a few AE activities at the first stage, which is followed by a rapid growth along with intense acoustic emission activities at the damage acceleration stage. Moreover, there is a sharp rise in the damage evolution curve for the natural-state specimen at the damage acceleration stage, while the damage variable develops slowly for the saturated-state specimen.

Effect of Polyethylene Jacket on Swelling Behavior and Mechanical Properties of PVA Hydrogel Nucleus Pulposus Prosthesis

2011 ◽  
Vol 287-290 ◽  
pp. 2042-2045 ◽  
Author(s):  
Jin Gao ◽  
Wei Zhu ◽  
Xian Zhou ◽  
Xiao Gang Li
Keyword(s):  
Mechanical Properties ◽  
Nucleus Pulposus ◽  
Free Water ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Relaxation Property ◽  
Dsc Analysis ◽  
Equilibrium Water Content ◽  
Ultrahigh Molecular Weight ◽  
Pva Hydrogel ◽  
Dimension Ratio

New prosthetic nucleus which consisted of ultrahigh molecular weight polyethylene (UHMWPE) jacket and polyvinyl alcohol (PVA) hydrogel core was prepared and studied. The hydrogels with similar size were encased in polyethylene jacket of different dimension. Studies indicate that with the decrease of jacket dimension, swelling time of prosthetic nucleus increases, the equilibrium water content and volume change ratio decrease. Differential Scanning Caborimetry (DSC) analysis shows that increasing the jacket dimension results in a slight increase of non-freezable bond water and significant increase in free water. The prosthetic nucleus with larger jacket has better stress relaxation property due to the plasticization of non-freezable water. These results suggest that the dimension ratio of jacket to core at 1.19-1.35 is the most suitable for artificial nucleus pulposus

scholarly journals Acetyl hexapeptide-3 in a cosmetic formulation acts on skin mechanical properties - clinical study

2015 ◽  
Vol 51 (4) ◽  
pp. 901-909 ◽  
Author(s):  
Kassandra Azevedo Tadini ◽  
Daiane Garcia Mercurio ◽  
Patrícia Maria Berardo Gonçalves Maia Campos
Keyword(s):  
Mechanical Properties ◽  
Stratum Corneum ◽  
Water Content ◽  
Topical Formulations ◽  
Face Area ◽  
Cutaneous Tissue ◽  
The Face ◽  
Skin Conditions ◽  
Basic Studies ◽  
Stratum Corneum Water Content

abstract Acetyl hexapeptide-3 has been used in anti-aging topical formulations aimed at improving skin appearance. However, few basic studies address its effects on epidermis and dermis, when vehiculated in topical formulations. Thus, the objective of this study was to determine the clinical efficacy of acetyl hexapeptide-3 using biophysical techniques. For this purpose, formulations with and without acetyl hexapeptide-3 were applied to the ventral forearm and the face area of forty female volunteers. Skin conditions were evaluated after 2 and 4-week long daily applications, by analyzing the stratum corneum water content and the skin mechanical properties, using three instruments, the Corneometer(r) CM 825, CutometerSEM 575 and ReviscometerRV600. All formulations tested increased the stratum corneum water content in the face region, which remained constant until the end of the study. In contrast, only formulations containing acetyl hexapeptide-3 exhibit a significant effect on mechanical properties, by decreasing the anisotropy of the face skin. No significant effects were observed in viscoelasticity parameters. In conclusion, the effects of acetyl hexapeptide-3 on the anisotropy of face skin characterize the compound as an effective ingredient for improving conditions of the cutaneous tissue, when used in anti-aging cosmetic formulations.

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