Effect of Cold Storage and Freezing on the Biomechanical Properties of Swine Growth Plate Explants

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Anne-Laure Ménard ◽  
Candice Soulisse ◽  
Pascale Raymond ◽  
Irène Londono ◽  
Isabelle Villemure
Keyword(s):  
Growth Plate ◽  
Cold Storage ◽  
Ex Vivo ◽  
Biomechanical Properties ◽  
Storage Conditions ◽  
Transportation Costs ◽  
Equilibrium Stress ◽  
Essential Information ◽  
Biomechanical Parameters ◽  
Matrix Modulus

Ex vivo biomechanical testing of growth plate samples provides essential information about its structural and physiological characteristics. Experimental limitations include the preservation of the samples since working with fresh tissues involves significant time and transportation costs. Little information is available on the storage of growth plate explants. The aim of this study was to determine storage conditions that could preserve growth plate biomechanical properties. Porcine ulnar growth plate explants (n = 5 per condition) were stored at either 4 °C for periods of 1, 2, 3, and 6 days or frozen at −20 °C with slow or rapid sample thawing. Samples were tested using stress relaxation tests under unconfined compression to assess five biomechanical parameters. The maximum compressive stress (σmax) and the equilibrium stress (σeq) were directly extracted from the experimental curves, while the fibril-network reinforced biphasic model was used to obtain the matrix modulus (Em), the fibril modulus (Ef), and the permeability (k). No significant changes were observed in σeq and Em in any of the tested storage conditions. Significant decreases and increases, respectively, were observed in σmax and k in the growth plate samples refrigerated for more than 48 h and in the frozen samples, when compared with the fresh samples. The fibril modulus Ef of all stored samples was significantly reduced compared to the fresh samples. These results indicate that the storage of growth plates in a humid chamber at 4 °C for a maximum of 48 h is the condition that minimizes the effects on the measured biomechanical parameters, with only Ef significantly reduced. Refrigerating growth plate explants for less than 48 h maintains their maximal stress, equilibrium stress, matrix modulus, and permeability. However, cold storage at 4 °C for more than 48 h and freezing storage at −20 °C significantly alter the biomechanical response of growth plate samples. Appropriate growth plate sample storage will be beneficial to save time and reduce transportation costs to pick up fresh samples.

scholarly journals Histological, Biomechanical, and Biological Properties of Genipin-Crosslinked Decellularized Peripheral Nerves

2021 ◽  
Vol 22 (2) ◽  
pp. 674
Author(s):  
Óscar Darío García-García ◽  
Marwa El Soury ◽  
David González-Quevedo ◽  
David Sánchez-Porras ◽  
Jesús Chato-Astrain ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Nerve Repair ◽  
Wistar Rat ◽  
Biomechanical Properties ◽  
Biological Properties ◽  
Suitable Alternative ◽  
Promising Alternative ◽  
Histological Pattern ◽  
The Impact

Acellular nerve allografts (ANGs) represent a promising alternative in nerve repair. Our aim is to improve the structural and biomechanical properties of biocompatible Sondell (SD) and Roosens (RS) based ANGs using genipin (GP) as a crosslinker agent ex vivo. The impact of two concentrations of GP (0.10% and 0.25%) on Wistar rat sciatic nerve-derived ANGs was assessed at the histological, biomechanical, and biocompatibility levels. Histology confirmed the differences between SD and RS procedures, but not remarkable changes were induced by GP, which helped to preserve the nerve histological pattern. Tensile test revealed that GP enhanced the biomechanical properties of SD and RS ANGs, being the crosslinked RS ANGs more comparable to the native nerves used as control. The evaluation of the ANGs biocompatibility conducted with adipose-derived mesenchymal stem cells cultured within the ANGs confirmed a high degree of biocompatibility in all ANGs, especially in RS and RS-GP 0.10% ANGs. Finally, this study demonstrates that the use of GP could be an efficient alternative to improve the biomechanical properties of ANGs with a slight impact on the biocompatibility and histological pattern. For these reasons, we hypothesize that our novel crosslinked ANGs could be a suitable alternative for future in vivo preclinical studies.

In Vivo and ex Vivo Approaches to Studying the Biomechanical Properties of Healing Wounds in Rat Skin

2013 ◽  
Vol 135 (10) ◽  
Author(s):  
Clare Y. L. Chao ◽  
Gabriel Y. F. Ng ◽  
Kwok-Kuen Cheung ◽  
Yong-Ping Zheng ◽  
Li-Ke Wang ◽  
...  
Keyword(s):  
Wound Healing ◽  
Ex Vivo ◽  
Normal Skin ◽  
Biomechanical Properties ◽  
Skin Wound ◽  
Sprague Dawley ◽  
Rat Skin ◽  
Mechanical Stiffness ◽  
Air Jet

An evaluation of wound mechanics is crucial in reflecting the wound healing status. The present study examined the biomechanical properties of healing rat skin wounds in vivo and ex vivo. Thirty male Sprague-Dawley rats, each with a 6 mm full-thickness circular punch biopsied wound at both posterior hind limbs were used. The mechanical stiffness at both the central and margins of the wound was measured repeatedly in five rats over the same wound sites to monitor the longitudinal changes over time of before wounding, and on days 0, 3, 7, 10, 14, and 21 after wounding in vivo by using an optical coherence tomography-based air-jet indentation system. Five rats were euthanized at each time point, and the biomechanical properties of the wound tissues were assessed ex vivo using a tensiometer. At the central wound bed region, the stiffness measured by the air-jet system increased significantly from day 0 (17.2%), peaked at day 7 (208.3%), and then decreased progressively until day 21 (40.2%) as compared with baseline prewounding status. The biomechanical parameters of the skin wound samples measured by the tensiometer showed a marked reduction upon wounding, then increased with time (all p < 0.05). On day 21, the ultimate tensile strength of the skin wound tissue approached 50% of the normal skin; while the stiffness of tissue recovered at a faster rate, reaching 97% of its prewounded state. Our results suggested that it took less time for healing wound tissues to recover their stiffness than their maximal strength in rat skin. The stiffness of wound tissues measured by air-jet could be an indicator for monitoring wound healing and contraction.

TBS Association with Biomechanical Properties of Human Vertebrae, Ex-Vivo

2018 ◽  
Vol 21 (1) ◽  
pp. 30 ◽  
Author(s):  
D. Tran ◽  
F. Michelet ◽  
C. Lelong ◽  
D. Hans
Keyword(s):  
Ex Vivo ◽  
Biomechanical Properties

scholarly journals Influence of cold-storage conditions on renal function of autotransplanted large pig kidneys

2000 ◽  
Vol 58 (2) ◽  
pp. 838-850 ◽  
Author(s):  
Jean Michel Goujon ◽  
Alain Vandewalle ◽  
Herve Baumert ◽  
Michel Carretier ◽  
Thierry Hauet
Keyword(s):  
Renal Function ◽  
Cold Storage ◽  
Storage Conditions

Consequences of head injury and static cold storage on hepatic function: ex vivo experiments using a model of isolated perfused rat liver

Metabolism ◽  
2009 ◽  
Vol 58 (11) ◽  
pp. 1550-1556 ◽  
Author(s):  
Eric Levesque ◽  
Christophe Moinard ◽  
Valérie Besson ◽  
Nathalie Neveux ◽  
Jean-Claude Chaumeil ◽  
...  
Keyword(s):  
Head Injury ◽  
Rat Liver ◽  
Cold Storage ◽  
Ex Vivo ◽  
Hepatic Function ◽  
Isolated Perfused Rat Liver ◽  
Perfused Rat Liver

scholarly journals Fruit quality preservation of 'Laetitia' plums under controlled atmosphere storage

2014 ◽  
Vol 86 (1) ◽  
pp. 485-494 ◽  
Author(s):  
CRISTIANO ANDRÉ STEFFENS ◽  
CASSANDRO V.T. DO AMARANTE ◽  
ERLANI O. ALVES ◽  
AURI BRACKMANN
Keyword(s):  
Fruit Quality ◽  
Cold Storage ◽  
Ethylene Production ◽  
Titratable Acidity ◽  
Storage Conditions ◽  
Controlled Atmosphere ◽  
Controlled Atmosphere Storage ◽  
Red Color ◽  
High Incidence ◽  
Atmosphere Storage

The objective of this study was to evaluate the effect of controlled atmosphere (CA) on quality preservation of ‘Laetitia’ plums, mainly on internal breakdown, in order to determine the best CA storage conditions. Two experiments were carried out one in 2010, and another in 2011. In 2010, besides cold storage (CS; 21.0 kPa O2 + 0.03 kPa CO2), the fruits were stored under the following CA conditions (kPa O2+kPa CO2): 1+3, 1+5, 2+5, 2+10, and 11+10. In 2011, the fruits were stored under CS and CA of 1+0, 1+1, 2+1, and 2+2. The fruit stored under different CA conditions had lower respiration and ethylene production, better preservation of flesh firmness, texture and titratable acidity, lower skin red color, and lower incidence of skin cracking than the fruit in CS. In 2010, the fruit under CA with 2+5, 1+5, and 1+3 had a pronounced delay in ripening, although it exhibited a high incidence of internal breakdown. In 2011, the CA conditions with 2+1 and 2+2 provided the best delay in ripening and a reduced incidence of internal breakdown. The best CA condition for cold storage (at 0.5°C) of ‘Laetitia’ plums is 2 kPa O2 + 2 kPa CO2.

scholarly journals Corneal Biomechanical Properties in Varying Severities of Myopia

2021 ◽  
Vol 8 ◽  
Author(s):  
Mohammad-Reza Sedaghat ◽  
Hamed Momeni-Moghaddam ◽  
Abbas Azimi ◽  
Zohreh Fakhimi ◽  
Mohammed Ziaei ◽  
...  
Keyword(s):  
Axial Length ◽  
Corneal Thickness ◽  
Biomechanical Properties ◽  
Cross Sectional Study ◽  
Geometrical Parameters ◽  
Cross Sectional ◽  
Corvis St ◽  
Multiple Parameters ◽  
Inverse Radius ◽  
Biomechanical Parameters

Purpose: To investigate corneal biomechanical response parameters in varying degrees of myopia and their correlation with corneal geometrical parameters and axial length.Methods: In this prospective cross-sectional study, 172 eyes of 172 subjects, the severity degree of myopia was categorized into mild, moderate, severe, and extreme myopia. Cycloplegic refraction, corneal tomography using Pentacam HR, corneal biomechanical assessment using Corvis ST and Ocular Response Analyser (ORA), and ocular biometry using IOLMaster 700 were performed for all subjects. A general linear model was used to compare biomechanical parameters in various degrees of myopia, while central corneal thickness (CCT) and biomechanically corrected intraocular pressure (bIOP) were considered as covariates. Multiple linear regression was used to investigate the relationship between corneal biomechanical parameters with spherical equivalent (SE), axial length (AXL), bIOP, mean keratometry (Mean KR), and CCT.Results: Corneal biomechanical parameters assessed by Corvis ST that showed significant differences among the groups were second applanation length (AL2, p = 0.035), highest concavity radius (HCR, p &lt; 0.001), deformation amplitude (DA, p &lt; 0.001), peak distance (PD, p = 0.022), integrated inverse radius (IR, p &lt; 0.001) and DA ratio (DAR, p = 0.004), while there were no significant differences in the means of pressure-derived parameters of ORA between groups. Multiple regression analysis showed all parameters of Corvis ST have significant relationships with level of myopia (SE, AXL, Mean KR), except AL1 and AL2. Significant biomechanical parameters showed progressive reduction in corneal stiffness with increasing myopia (either with greater negative SE or greater AXL), independent of IOP and CCT. Also, corneal hysteresis (CH) or ability to dissipate energy from the ORA decreased with increasing level of myopia.Conclusions: Dynamic corneal response assessed by Corvis ST shows evidence of biomechanical changes consistent with decreasing stiffness with increasing levels of myopia in multiple parameters. The strongest correlations were with highest concavity parameters where the sclera influence is maximal.

scholarly journals An ECHO of Cartilage: In Silico Prediction of Combinatorial Treatments to Switch Between Transient and Permanent Cartilage Phenotypes With Ex Vivo Validation

2021 ◽  
Vol 9 ◽  
Author(s):  
Sakshi Khurana ◽  
Stefano Schivo ◽  
Jacqueline R. M. Plass ◽  
Nikolas Mersinis ◽  
Jetse Scholma ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Model Checking ◽  
Cell Fate ◽  
Growth Plate ◽  
Ex Vivo ◽  
Boolean Model ◽  
Zonal Distribution ◽  
Cell Fate Decisions ◽  
Hypertrophic Cartilage ◽  
Cartilage Formation

A fundamental question in cartilage biology is: what determines the switch between permanent cartilage found in the articular joints and transient hypertrophic cartilage that functions as a template for bone? This switch is observed both in a subset of OA patients that develop osteophytes, as well as in cell-based tissue engineering strategies for joint repair. A thorough understanding of the mechanisms regulating cell fate provides opportunities for treatment of cartilage disease and tissue engineering strategies. The objective of this study was to understand the mechanisms that regulate the switch between permanent and transient cartilage using a computational model of chondrocytes, ECHO. To investigate large signaling networks that regulate cell fate decisions, we developed the software tool ANIMO, Analysis of Networks with interactive Modeling. In ANIMO, we generated an activity network integrating 7 signal transduction pathways resulting in a network containing over 50 proteins with 200 interactions. We called this model ECHO, for executable chondrocyte. Previously, we showed that ECHO could be used to characterize mechanisms of cell fate decisions. ECHO was first developed based on a Boolean model of growth plate. Here, we show how the growth plate Boolean model was translated to ANIMO and how we adapted the topology and parameters to generate an articular cartilage model. In ANIMO, many combinations of overactivation/knockout were tested that result in a switch between permanent cartilage (SOX9+) and transient, hypertrophic cartilage (RUNX2+). We used model checking to prioritize combination treatments for wet-lab validation. Three combinatorial treatments were chosen and tested on metatarsals from 1-day old rat pups that were treated for 6 days. We found that a combination of IGF1 with inhibition of ERK1/2 had a positive effect on cartilage formation and growth, whereas activation of DLX5 combined with inhibition of PKA had a negative effect on cartilage formation and growth and resulted in increased cartilage hypertrophy. We show that our model describes cartilage formation, and that model checking can aid in choosing and prioritizing combinatorial treatments that interfere with normal cartilage development. Here we show that combinatorial treatments induce changes in the zonal distribution of cartilage, indication possible switches in cell fate. This indicates that simulations in ECHO aid in describing pathologies in which switches between cell fates are observed, such as OA.

scholarly journals Protective effect of zinc-N-acetylcysteine on the rat kidney during cold storage

2013 ◽  
Vol 305 (7) ◽  
pp. F1022-F1030 ◽  
Author(s):  
Mandeep Singh ◽  
Dolapo T. Odeniyi ◽  
Eugene O. Apostolov ◽  
Alena Savenka ◽  
Todd Fite ◽  
...  
Keyword(s):  
Cell Death ◽  
Dna Fragmentation ◽  
Cold Storage ◽  
Ex Vivo ◽  
Rat Kidney ◽  
Maximum Effect ◽  
Kidney Preservation ◽  
Endonuclease G ◽  
Normal Rat ◽  
Rat Kidneys

Cold storage of kidneys before transplantation is problematic because of the limited survival time of the allografts. In this study, zinc- N-acetylcysteine (ZnNAC) was shown to be a potent endonuclease inhibitor and antioxidant, and it was tested as a potential additive to a cold storage solution for kidney preservation. Exposure of normal rat kidney NRK-52E cells to ZnNAC resulted in zinc delivery to the cells as determined by TFL-Zn fluorophore and partial protection of the cells against injury by cold storage in University of Wisconsin solution (UWS) as measured by propidium iodide assay. Ex vivo, rat kidneys demonstrated time- and temperature-dependent DNA fragmentation as assessed by TUNEL assay, indicating irreversible cell death. DNA fragmentation was faster in the medulla than in the cortex, and tubules were affected more than glomeruli. Perfusion of rat kidneys with cold ZnNAC solution in UWS significantly inhibited cell death both in the cortex and medulla at concentrations of 0.3–30 mM compared with UWS alone, with a maximum effect at 1–10 mM ZnNAC. Cold storage of the kidney significantly increased quantities of cleaved caspase-3 and endonuclease G (EndoG) in the tissue, which were abolished by 10 mM ZnNAC, indicating its ability to suppress both caspase-dependent and -independent cell death. Therefore, supplementation of UWS with ZnNAC can decrease DNA fragmentation and protect kidney allografts from cell death due to cold storage.

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