scholarly journals Characterizing the viscoelastic properties of thin hydrogel-based constructs for tissue engineering applications

2005 ◽  
Vol 2 (5) ◽  
pp. 455-463 ◽  
Author(s):  
Mark Ahearne ◽  
Ying Yang ◽  
Alicia J El Haj ◽  
Kong Y Then ◽  
Kuo-Kang Liu
Keyword(s):  
Tissue Engineering ◽  
Viscoelastic Properties ◽  
Biological Tissues ◽  
Constant Load ◽  
Time Dependent ◽  
Hydrogel Membranes ◽  
Agarose Hydrogel ◽  
Viscoelastic Theory ◽  
Working Distance ◽  
Convenient Technique

We present a novel indentation method for characterizing the viscoelastic properties of alginate and agarose hydrogel based constructs, which are often used as a model system of soft biological tissues. A sensitive long working distance microscope was used for measuring the time-dependent deformation of the thin circular hydrogel membranes under a constant load. The deformation of the constructs was measured laterally. The elastic modulus as a function of time can be determined by a large deformation theory based on Mooney–Rivlin elasticity. A viscoelastic theory, Zener model, was applied to correlate the time-dependent deformation of the constructs with various gel concentrations, and the creep parameters can therefore be quantitatively estimated. The value of Young's modulus was shown to increase in proportion with gel concentration. This finding is consistent with other publications. Our results also showed the great capability of using the technique to measure gels with incorporated corneal stromal cells. This study demonstrates a novel and convenient technique to measure mechanical properties of hydrogel in a non-destructive, online and real-time fashion. Thus this novel technique can become a valuable tool for soft tissue engineering.

scholarly journals Protein Hydrogels: The Swiss Army Knife for Enhanced Mechanical and Bioactive Properties of Biomaterials

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1656
Author(s):  
Carla Huerta-López ◽  
Jorge Alegre-Cebollada
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Polymer Networks ◽  
Biological Tissues ◽  
Modern Medicine ◽  
Body Parts ◽  
Biomedical Sciences ◽  
Protein Hydrogels ◽  
Large Water ◽  
Design Options

Biomaterials are dynamic tools with many applications: from the primitive use of bone and wood in the replacement of lost limbs and body parts, to the refined involvement of smart and responsive biomaterials in modern medicine and biomedical sciences. Hydrogels constitute a subtype of biomaterials built from water-swollen polymer networks. Their large water content and soft mechanical properties are highly similar to most biological tissues, making them ideal for tissue engineering and biomedical applications. The mechanical properties of hydrogels and their modulation have attracted a lot of attention from the field of mechanobiology. Protein-based hydrogels are becoming increasingly attractive due to their endless design options and array of functionalities, as well as their responsiveness to stimuli. Furthermore, just like the extracellular matrix, they are inherently viscoelastic in part due to mechanical unfolding/refolding transitions of folded protein domains. This review summarizes different natural and engineered protein hydrogels focusing on different strategies followed to modulate their mechanical properties. Applications of mechanically tunable protein-based hydrogels in drug delivery, tissue engineering and mechanobiology are discussed.

scholarly journals Computer modelling and simulation of a novel printing head for complex tissue engineering constructs

2020 ◽  
Vol 318 ◽  
pp. 01045
Author(s):  
Gokhan Ates
Keyword(s):  
Tissue Engineering ◽  
Computer Modelling ◽  
Three Dimensional ◽  
Biological Tissues ◽  
Biological Properties ◽  
Functionally Graded ◽  
Mixing Efficiency ◽  
Tissue Constructs ◽  
Multiple Materials ◽  
Graded Structures

In tissue engineering, three-dimensional functional scaffolds with tailored biological properties are needed to be able to mimic the hierarchical structure of biological tissues. Recent developments in additive biomanufacturing allow to extrude multiple materials enabling the fabrication of more sophisticated tissue constructs. These multi-material biomanufacturing systems comprise multiple printing heads through which individual materials are sequentially printed. Nevertheless, as more printing heads are added the fabrication process significantly decreases, since it requires mechanical switching among the physically separated printheads to enable printing multiple materials. In addition, this approach is not able to create biomimetic tissue constructs with property gradients. To address these limitations, this paper presents a novel static mixing extrusion printing head to enable the fabrication of multi-material, functionally graded structures using a single nozzle. Computational fluid dynamics (CFD) was used to numerically analyze the influence of Reynolds number on the flow pattern of biomaterials and mixing efficiency considering different miscible materials.

Ex vivo characterization of a novel tissue-like cross-linked fibrin-agarose hydrogel for tissue engineering applications

2016 ◽  
Vol 11 (5) ◽  
pp. 055004 ◽  
Author(s):  
Fernando Campos ◽  
Ana B Bonhome-Espinosa ◽  
Laura García-Martínez ◽  
Juan D G Durán ◽  
Modesto T López-López ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Ex Vivo ◽  
Engineering Applications ◽  
Agarose Hydrogel

Evaluation of the Viscoelastic Properties of the Intact Medial Collateral Ligament in a Goat Model

1999 ◽  
Author(s):  
Theodore D. Clineff ◽  
Richard E. Debski ◽  
Sven U. Scheffler ◽  
John D. Withrow ◽  
Savio L.-Y. Woo
Keyword(s):  
Medial Collateral Ligament ◽  
Viscoelastic Properties ◽  
Analytical Approach ◽  
Cruciate Ligament ◽  
Collateral Ligament ◽  
Future Studies ◽  
Linear Viscoelastic ◽  
Viscoelastic Theory ◽  
Anterior Cruciate ◽  
Linear Viscoelastic Theory

Abstract The time and history dependent viscoelastic properties have been determined for the normal medial collateral ligament (MCL) of canine (Woo, 1981), porcine anterior cruciate ligament (Kwan, 1993), and human patellar tendon in a cadaver model (Johnson, 1994). The objective of this study was to use a combined experimental and analytical approach to quantify the viscoelastic properties of the intact MCL in a goat model. A thorough understanding of the viscoelastic properties at low strain levels is necessary to future studies of the healing MCL. The quasi-linear viscoelastic theory (QLV) (Fung, 1972) was used to characterize the properties of the MCL during stress relaxation.

One-dimensional consolidation of multilayered aquifer systems with viscoelastic properties induced by time-dependent groundwater drawdown

2021 ◽  
pp. qjegh2021-073
Author(s):  
Weitao Yang ◽  
Jin Xu
Keyword(s):  
Viscoelastic Properties ◽  
Numerical Solutions ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Time Dependent ◽  
Analytical Models ◽  
Consolidation Process ◽  
One Dimensional ◽  
Groundwater Drawdown ◽  
Aquifer Systems

Most analytical and semi-analytical models for pumping-induced land subsidence invoke the simplifying assumptions regarding characteristics of geomaterials, as well as the pattern of drawdown response to pumping. This paper presents an analytical solution for one-dimensional consolidation of the multilayered soil due to groundwater drawdown, in which viscoelastic property and time-dependent drawdown are taken into account. The presented solution is developed by using the boundary transformation techniques. The validity of the proposed solution is verified by comparing with a degenerated case for a single layer, as well as with the numerical solutions and experimental results for a two-layer system. The difference between the average consolidation degree Up defined by hydraulic head and that Us defined by total settlement is discussed. The detailed parametric studies are conducted to reveal the effects of viscoelastic properties and drawdown patterns on the consolidation process. It is revealed that while the effect of different drawdown response patterns is significant during the early-intermediate stages of consolidation, the viscoelastic properties may have a more dominant influence on long-term consolidation behavior, depending on the values of the material parameters, which are reflected in both the deformation process of soil layers and the dissipation of excess pore-water pressure.

DEVELOPMENTAL STATUS AND PERSPECTIVES FOR TISSUE ENGINEERING IN UROLOGY

2021 ◽  
Vol 12 (07) ◽  
pp. 5-13
Author(s):  
Elcin Nizami Huseyn ◽  
Keyword(s):  
Tissue Engineering ◽  
Biological Materials ◽  
Organ Damage ◽  
Biological Tissues ◽  
Tissue Cell ◽  
Sperm Cells ◽  
Engineering Technology ◽  
The Future ◽  
Tissue Engineering Technology

Tissue engineering technology and tissue cell-based stem cell research have made great strides in treating tissue and organ damage, correcting tissue and organ dysfunction, and reducing surgical complications. In the past, traditional methods have used biological substitutes for tissue repair materials, while tissue engineering technology has focused on merging sperm cells with biological materials to form biological tissues with the same structure and function as their own tissues. The advantage is that tissue engineering technology can overcome donors. Material procurement restrictions can effectively reduce complications. The aim of studying tissue engineering technology is to find sperm cells and suitable biological materials to replace the original biological functions of tissues and to establish a suitable in vivo microenvironment. This article mainly describes the current developments of tissue engineering in various fields of urology and discusses the future trends of tissue engineering technology in the treatment of complex diseases of the urinary system. The results of the research in this article indicate that while the current clinical studies are relatively few, the good results from existing animal model studies indicate good prospects of tissue engineering technology for the treatment of various urinary tract diseases in the future. Key words: Tissue engineering, kidney, ureter, bladder, urethra

scholarly journals In vitro characterization of a novel magnetic fibrin-agarose hydrogel for cartilage tissue engineering

2020 ◽  
Vol 104 ◽  
pp. 103619 ◽  
Author(s):  
Ana Belén Bonhome-Espinosa ◽  
Fernando Campos ◽  
Daniel Durand-Herrera ◽  
José Darío Sánchez-López ◽  
Sébastien Schaub ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cartilage Tissue Engineering ◽  
Cartilage Tissue ◽  
In Vitro Characterization ◽  
Agarose Hydrogel

Tissue Engineering with Natural Tissue Matrices

2010 ◽  
Vol 76 ◽  
pp. 125-132 ◽  
Author(s):  
Akio Kishida ◽  
Seiichi Funamoto ◽  
Jun Negishi ◽  
Yoshihide Hashimoto ◽  
Kwangoo Nam ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Blood Vessel ◽  
Heart Valve ◽  
Biomechanical Properties ◽  
Biological Tissues ◽  
The Novel ◽  
Detergent Treatment ◽  
Decellularized Tissue ◽  
Natural Tissue ◽  
Porcine Tissues

Natural tissue, especially autologous tissue is one of ideal materials for tissue regeneration. Decellularized tissue could be assumed as a second choice because the structure and the mechanical properties are well maintained. Decellularized human tissues, for instance, heart valve, blood vessel, and corium, have already been developed and applied clinically. Nowadays, decellularized porcine tissues are also investigated. These decellularized tissues were prepared by detergent treatment. The detergent washing is easy but sometime it has problems. We have developed the novel decellularization method, which applied the high-hydrostatic pressure (HHP). As the tissue set in the pressurizing chamber is treated uniformly, the effect of the high-hydrostatic pressurization does not depend on the size of tissue. We have reported the HHP decellularization of heart valve, blood vessel, bone, and cornea. Furthermore, HHP treatments are reported to have the ability of the extinction of bacillus and the inactivation of virus. So, the HHP treatment is also expected as the sterilization method. We are investigating efficient processes of decellularization and recellularization of biological tissues to have bioscaffolds keeping intact structure and biomechanical properties. Our recent studies on tissue engineering using HHP decellularized tissue will be reported here.

scholarly journals The use of auxetic materials in tissue engineering

2020 ◽  
Vol 8 (8) ◽  
pp. 2074-2083 ◽  
Author(s):  
Paul Mardling ◽  
Andrew Alderson ◽  
Nicola Jordan-Mahy ◽  
Christine Lyn Le Maitre
Keyword(s):  
Tissue Engineering ◽  
Biological Tissues ◽  
Auxetic Materials ◽  
Potential Applications ◽  
Poissons Ratio

A number of biological tissues have been shown to behave in an auxetic manner, defined by having a negative poissons ratio. Thus mimicking this environment has a number of potential applications especially in tissue engineering.

scholarly journals Microstructure and Mechanical Property of Glutaraldehyde-Treated Porcine Pulmonary Ligament

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Huan Chen ◽  
Xuefeng Zhao ◽  
Zachary C. Berwick ◽  
Joshua F. Krieger ◽  
Sean Chambers ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Tissue Engineering ◽  
Multiphoton Microscopy ◽  
Longitudinal Direction ◽  
Orientation Distribution ◽  
Biological Tissues ◽  
Collagen Fibers ◽  
Biaxial Stress ◽  
Constitutive Law ◽  
Fresh Specimen

There is a significant need for fixed biological tissues with desired structural and material constituents for tissue engineering applications. Here, we introduce the lung ligament as a fixed biological material that may have clinical utility for tissue engineering. To characterize the lung tissue for potential clinical applications, we studied glutaraldehyde-treated porcine pulmonary ligament (n = 11) with multiphoton microscopy (MPM) and conducted biaxial planar experiments to characterize the mechanical property of the tissue. The MPM imaging revealed that there are generally two families of collagen fibers distributed in two distinct layers: The first family largely aligns along the longitudinal direction with a mean angle of θ = 10.7 ± 9.3 deg, while the second one exhibits a random distribution with a mean θ = 36.6 ± 27.4. Elastin fibers appear in some intermediate sublayers with a random orientation distribution with a mean θ = 39.6 ± 23 deg. Based on the microstructural observation, a microstructure-based constitutive law was proposed to model the elastic property of the tissue. The material parameters were identified by fitting the model to the biaxial stress–strain data of specimens, and good fitting quality was achieved. The parameter e0  (which denotes the strain beyond which the collagen can withstand tension) of glutaraldehyde-treated tissues demonstrated low variability implying a relatively consistent collagen undulation in different samples, while the stiffness parameters for elastin and collagen fibers showed relatively greater variability. The fixed tissues presented a smaller e0 than that of fresh specimen, confirming that glutaraldehyde crosslinking increases the mechanical strength of collagen-based biomaterials. The present study sheds light on the biomechanics of glutaraldehyde-treated porcine pulmonary ligament that may be a candidate for tissue engineering.

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