Concentration Dependence of Tensile Behavior in Agarose Gel Using Digital Image Correlation

Subhash, Ghatu; Liu, Q.; Moore, David F.; Ifju, Peter; Haile, Mulugeta

doi:10.1007/s11340-010-9354-2

Cited by 39 publications

(46 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Taken together, hydrogels with gradient mechanics were successfully prepared while their other physical properties also changed accordingly. Although the Young's modulus values measured, herein, are comparable to those reported by Benkherourou et al [24], divergent outcomes have also been documented which can be attributed to multiple factors including, but not limited to, the type of agarose, agarose viscosity, and mechanical testing (for example, confined versus unconfined compression and local versus bulk property) [19,22,[25][26][27]. Overall, our data suggest that agarose contents largely contribute to the initial mechanical strength possessed by hydrogels and limited unfilled space exists in the network of hydrogels with higher agarose concentrations.…”

Section: Agarose Hydrogels With Varied Mechanicssupporting

confidence: 71%

In Vitro Evaluation of the Influence of Substrate Mechanics on Matrix-Assisted Human Chondrocyte Transplantation

Yang

Ogando

Barabino

2020

JFB

View full text Add to dashboard Cite

Matrix-assisted chondrocyte transplantation (MACT) is of great interest for the treatment of patients with cartilage lesions. However, the roles of the matrix properties in modulating cartilage tissue integration during MACT recovery have not been fully understood. The objective of this study was to uncover the effects of substrate mechanics on the integration of implanted chondrocyte-laden hydrogels with native cartilage tissues. To this end, agarose hydrogels with Young’s moduli ranging from 0.49 kPa (0.5%, w/v) to 23.08 kPa (10%) were prepared and incorporated into an in vitro human cartilage explant model. The hydrogel-cartilage composites were cultivated for up to 12 weeks and harvested for evaluation via scanning electron microscopy, histology, and a push-through test. Our results demonstrated that integration strength at the hydrogel-cartilage interface in the 1.0% (0.93 kPa) and 2.5% (3.30 kPa) agarose groups significantly increased over time, whereas hydrogels with higher stiffness (>8.78 kPa) led to poor integration with articular cartilage. Extensive sprouting of extracellular matrix in the interfacial regions was only observed in the 0.5% to 2.5% agarose groups. Collectively, our findings suggest that while neocartilage development and its integration with native cartilage are modulated by substrate elasticity, an optimal Young’s modulus (3.30 kPa) possessed by agarose hydrogels is identified such that superior quality of tissue integration is achieved without compromising tissue properties of implanted constructs.

show abstract

Section: Agarose Hydrogels With Varied Mechanicssupporting

confidence: 71%

In Vitro Evaluation of the Influence of Substrate Mechanics on Matrix-Assisted Human Chondrocyte Transplantation

Yang

Ogando

Barabino

2020

JFB

View full text Add to dashboard Cite

show abstract

“…Compressive loading was selected for investigation because compressive loading is known to have play an important role in mediating biosynthesis, remodeling, and repair of cartilage, 68 and many cartilage tissue engineering strategies focus on compressive loading within bioreactors. 18,19 There are previous reports from our laboratory and others describing PEG and agarose hydrogels, independently, under tension and shear, 8,14,34,[69][70][71] suggesting that agarose and PEG hydrogels under tension and shear may behave similarly to that observed under compression.…”

Section: Discussionmentioning

confidence: 89%

Comparative study of the viscoelastic mechanical behavior of agarose and poly(ethylene glycol) hydrogels

et al. 2011

View full text Add to dashboard Cite

This study presents a comparative investigation into differences in the mechanical properties between two hydrogels commonly used in cartilage tissue engineering [agarose vs. poly(ethylene glycol) (PEG)], but which are formed through distinctly different crosslinking mechanisms (physical vs. covalent, respectively). The effects of hydrogel chemistry, precursor concentration, platen type (nonporous vs. porous) used in compression bioreactors, and degradation (for PEG) on the swelling properties and static and dynamic mechanical properties were examined. An increase in precursor concentration resulted in decreased equilibrium mass swelling ratios but increased equilibrium moduli and storage moduli for both hydrogels (p < 0.05). Agarose displayed large stress relaxations and a frequency dependence indicating its viscoelastic properties. Contrarily, PEG hydrogels displayed largely elastic behavior with minimal stress relaxation and frequency dependence. In biodegradable PEG hydrogels, the largely elastic behavior was retained during degradation. The type of platen did not affect static mechanical properties, but porous platens led to a reduced storage modulus for both hydrogels implicating fluid flow. In summary, agarose and PEG exhibit vastly different mechanical behaviors; a finding largely attributed to differences in their chemistries and fluid movement. Taken together, these design choices (hydrogel chemistry/structure, loading conditions) will likely have a profound effect on the tissue engineering outcome.

show abstract

“…In this study, a polymer SHPB (PSHPB) system [31,[34][35][36] was used to generate lower magnitude stress and pressure waves in a fluid-filled acrylic test cell that mimicked shock waves generated within the head. A schematic of the test system is given in Fig.…”

Section: Experimental Methods High Strain Rate Test Systemmentioning

confidence: 99%

“…These speckles move with the object upon loading and by capturing the time resolved images of the deformed specimen, allow measurement of the displacement on the entire specimen. This technique has been employed by Subhash et al [34] to measure tensile deformation of agarose gel at various concentrations as well as our previous brain slice testing [31]. In the current study, high speed camera images of the deforming hydrogels were used to calculate displacement and strain of the hydrogel slices using the DIC method.…”

Section: Digital Image Correlation (Dic)mentioning

confidence: 97%

“…Agarose-based hydrogels have been previously used for brain surrogate studies [37,38]. Modulus values for this concentration (−0.27 kPa) are slightly higher than those measured for brain tissue slices [34,37]. To allow tracking of deformation, hydrogel slices were speckled with black ink (Accu stamp, Cosco Industries Inc., Harwood Heights, Illinois) with an air brush (model 200nh, Badger Air-Brush Co., Franklin Park, Illinois).…”

Section: Gel Slice Testingmentioning

confidence: 99%

See 1 more Smart Citation

Localized Tissue Surrogate Deformation due to Controlled Single Bubble Cavitation

et al. 2015

Self Cite

View full text Add to dashboard Cite

Cavitation-induced shock wave, as might occur in the head during exposure to blast waves, was investigated as a possible damage mechanism for soft brain tissues. A novel experimental technique was developed to visualize and control single bubble cavitation and its collapse, and the influence of this process on a nearby tissue surrogate was investigated. The experiment utilized a Hopkinson pressure bar system which transmits a simulated blast pressure wave (with over-pressure and under-pressure components) to a fluid-filled test chamber implanted with a seed gas bubble. Growth and collapse of this bubble was recorded during passage of the blast wave with a high speed camera. To investigate the potential for cavitation damage to a tissue surrogate, local changes in strain were measured in hydrogel slices placed in various configurations next to the bubble. The strain measurements were made using digital image correlation (DIC) technique by monitoring the motion of material points on the tissue surrogate. In one configuration, bubble contact dynamics resulted in compression contact (>60 μs) followed by inertially-driven tension (>140 μs). In another configuration, the influence of local shock waves emanating from collapsed bubbles was captured. Large compressive strains (0.25 to 0.5) that were highly localized (0.18 mm 2 ) were measured over a short time period (<24 μs) after bubble collapse. High bubble collapse pressures 29 to 125 times that of peak blast overpressure are predicted to be the source of these large strains. Consistent with theoretical predictions, these cavitation-based strains are far larger than the strains imposed by passage of the simulated blast wave alone. Finally, the value of this experimental platform to investigate the single bubble cavitation-induced damage in a biological tissue is illustrated with an example test on rat brain slices.

show abstract

Concentration Dependence of Tensile Behavior in Agarose Gel Using Digital Image Correlation

Cited by 39 publications

References 24 publications

In Vitro Evaluation of the Influence of Substrate Mechanics on Matrix-Assisted Human Chondrocyte Transplantation

In Vitro Evaluation of the Influence of Substrate Mechanics on Matrix-Assisted Human Chondrocyte Transplantation

Comparative study of the viscoelastic mechanical behavior of agarose and poly(ethylene glycol) hydrogels

Localized Tissue Surrogate Deformation due to Controlled Single Bubble Cavitation

Contact Info

Product

Resources

About