Analysis of resorbable mesh implants in short-term human muscular fascia cultures: a pilot study

Abstract Purpose Alteration in fascial tissue collagen composition represents a key factor in hernia etiology and recurrence. Both resorbable and non-resorbable meshes for hernia repair are currently used in the surgical setting. However, no study has investigated so far the role of different implant materials on collagen deposition and tissue remodeling in human fascia. The aim of the present study was to develop a novel ex vivo model of human soft tissue repair mesh implant, and to test its suitability to investigate the effects of different materials on tissue remodeling and collagen composition. Methods Resorbable poly-4-hydroxybutyrate and non-resorbable polypropylene mesh implants were embedded in human abdominal fascia samples, mimicking common surgical procedures. Calcein-AM/Propidium Iodide vital staining was used to assess tissue vitality. Tissue morphology was evaluated using Mallory trichrome and hematoxylin and eosin staining. Collagen type I and III expression was determined through immunostaining semi-quantification by color deconvolution. All analyses were performed after 54 days of culture. Results The established ex vivo model showed good viability at 54 days of culture, confirming both culture method feasibility and implants biocompatibility. Both mesh implants induced a disorganization of collagen fibers pattern. A statistically significantly higher collagen I/III ratio was detected in fascial tissue samples cultured with resorbable implants compared to either non-resorbable implants or meshes-free controls. Conclusion We developed a novel ex vivo model and provided evidence that resorbable polyhydroxybutyrate meshes display better biomechanical properties suitable for proper restoration in surgical hernia repair.

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Precision-Cut Kidney Slices as a Tool to Understand the Dynamics of Extracellular Matrix Remodeling in Renal Fibrosis

Biomarker Insights ◽

10.4137/bmi.s38439 ◽

2016 ◽

Vol 11 ◽

pp. BMI.S38439 ◽

Cited By ~ 7

Author(s):

Federica Genovese ◽

Zsolt S. Kàrpàti ◽

Signe H. Nielsen ◽

Morten A. Karsdal

Keyword(s):

Extracellular Matrix ◽

Collagen Type ◽

Interstitial Fibrosis ◽

Ex Vivo ◽

Collagen Type I ◽

Extracellular Matrix Remodeling ◽

Type I ◽

Matrix Remodeling ◽

Renal Interstitial Fibrosis ◽

Ex Vivo Model

The aim of this study was to set up an ex vivo model for renal interstitial fibrosis in order to investigate the extracellular matrix (ECM) turnover profile in the fibrotic kidney. We induced kidney fibrosis in fourteen 12-week-old male Sprague Dawley rats by unilateral ureteral obstruction (UUO) surgery of the right ureter. The left kidney (contralateral) was used as internal control. Six rats were sham operated and used as the control group. Rats were terminated two weeks after the surgery; the kidneys were excised and precision-cut kidney slices (PCKSs) were cultured for five days in serum-free medium. Markers of collagen type I formation (P1NP), collagen type I and III degradation (C1M and C3M), and α-smooth muscle actin (αSMA) were measured in the PCKS supernatants by enzyme-linked immunosorbent assay. P1NP, C1M, C3M, and α-SMA were increased up to 2- to 13-fold in supernatants of tissue slices from the UUO-ligated kidneys compared with the contralateral kidneys ( P < 0.001) and with the kidneys of sham-operated animals ( P < 0.0001). The markers could also reflect the level of fibrosis in different animals. The UUO PCKS ex vivo model provides a valuable translational tool for investigating the extracellular matrix remodeling associated with renal interstitial fibrosis.

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MT1-MMP–dependent neovessel formation within the confines of the three-dimensional extracellular matrix

The Journal of Cell Biology ◽

10.1083/jcb.200405001 ◽

2004 ◽

Vol 167 (4) ◽

pp. 757-767 ◽

Cited By ~ 223

Author(s):

Tae-Hwa Chun ◽

Farideh Sabeh ◽

Ichiro Ota ◽

Hedwig Murphy ◽

Kevin T. McDonagh ◽

...

Keyword(s):

Extracellular Matrix ◽

Endothelial Cells ◽

Cell Surface ◽

Type I Collagen ◽

Ex Vivo ◽

Three Dimensional ◽

Collagenolytic Activity ◽

Type I ◽

Ex Vivo Model

During angiogenesis, endothelial cells initiate a tissue-invasive program within an interstitial matrix comprised largely of type I collagen. Extracellular matrix–degradative enzymes, including the matrix metalloproteinases (MMPs) MMP-2 and MMP-9, are thought to play key roles in angiogenesis by binding to docking sites on the cell surface after activation by plasmin- and/or membrane-type (MT) 1-MMP–dependent processes. To identify proteinases critical to neovessel formation, an ex vivo model of angiogenesis has been established wherein tissue explants from gene-targeted mice are embedded within a three-dimensional, type I collagen matrix. Unexpectedly, neither MMP-2, MMP-9, their cognate cell-surface receptors (i.e., β3 integrin and CD44), nor plasminogen are essential for collagenolytic activity, endothelial cell invasion, or neovessel formation. Instead, the membrane-anchored MMP, MT1-MMP, confers endothelial cells with the ability to express invasive and tubulogenic activity in a collagen-rich milieu, in vitro or in vivo, where it plays an indispensable role in driving neovessel formation.

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Effect of sugar metabolite methylglyoxal on equine lamellar explants: An ex vivo model of laminitis

PLoS ONE ◽

10.1371/journal.pone.0253840 ◽

2021 ◽

Vol 16 (7) ◽

pp. e0253840

Author(s):

Cristina Vercelli ◽

Massimiliano Tursi ◽

Silvia Miretti ◽

Gessica Giusto ◽

Marco Gandini ◽

...

Keyword(s):

Ex Vivo ◽

Tissue Inhibitor Of Metalloproteinase ◽

Carbonyl Stress ◽

Dihydroxyacetone Phosphate ◽

High Concentration ◽

Ex Vivo Model ◽

Experimental Conditions ◽

Irreversible Damage ◽

Tissue Samples ◽

Separation Force

Laminitis is one of the most devastating diseases in equine medicine, and although several etiopathogenetic mechanisms have been proposed, few clear answers have been identified to date. Several lines of evidence point towards its underlying pathology as being metabolism-related. In the carbonyl stress pathway, sugars are converted to methylglyoxal (MG)—a highly reactive α-oxoaldehyde, mainly derived during glycolysis in eukaryotic cells from the triose phosphates: D-glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. One common hypothesis is that MG could be synthesized during the digestive process in horses, and excessive levels absorbed into peripheral blood could be delivered to the foot and lead to alterations in the hoof lamellar structure. In the present study, employing an ex vivo experimental design, different concentrations of MG were applied to hoof explants (HE), which were then incubated and maintained in a specific medium for 24 and 48 h. Macroscopic and histological analyses and a separation force test were performed at 24 and 48 h post-MG application. Gene expression levels of matrix metalloproteinase (MMP)-2 and -14 and tissue inhibitor of metalloproteinase (TIMP)-2 were also measured at each time point for all experimental conditions. High concentrations of MG induced macroscopic and histological changes mimicking laminitis. The separation force test revealed that hoof tissue samples incubated for 24 h in a high concentration of MG, or with lower doses but for a longer period (48 h), demonstrated significant weaknesses, and samples were easily separated. All results support that high levels of MG could induce irreversible damage in HEs, mimicking laminitis in an ex vivo model.

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The Role of Relaxin-2 in Tissue Remodeling of Chronic Rhinosinusitis With Nasal Polyps

American Journal of Rhinology and Allergy ◽

10.1177/1945892419843828 ◽

2019 ◽

Vol 33 (5) ◽

pp. 490-499 ◽

Cited By ~ 1

Author(s):

Yimin Li ◽

Guojing Tan ◽

Jie Liu ◽

Xia Ke ◽

Yang Shen ◽

...

Keyword(s):

Western Blot ◽

Chronic Rhinosinusitis ◽

Nasal Polyps ◽

Ex Vivo ◽

Tissue Remodeling ◽

Collagen I ◽

Enzyme Linked Immunosorbent Assay ◽

Type I ◽

Relaxin 2 ◽

Tgf Β1

Background Relaxin is a small peptide hormone that regulates extracellular matrix remodeling and reduces fibrosis in a number of organs. Little is known about its impact on chronic rhinosinusitis with nasal polyps (CRSwNP); thus, we aimed to determine the expression of human H2 relaxin (relaxin-2) and its role in tissue remodeling in CRSwNP. Methods Patients were enrolled and divided into the following groups: CRS with NP (CRSwNP; n = 20), CRS without NP (CRSsNP; n = 20), and controls (n = 15). Tissue samples were analyzed by Masson trichrome staining for collagen, while the location and expression of relaxin-2, transforming growth factor beta 1 (TGF-β1), and phosphorylated (p) Smad2/Smad3 were analyzed by immunohistochemistry and Western blot. The expression of relaxin-2, Smad2, Smad3, and TGF-β1 mRNA was tested by quantitative polymerase chain reaction (qPCR). Ex vivo NP were treated with relaxin-2 (n = 15) or TGF-β1 (n = 15). Collagen type I (collagen I), relaxin-2, and TGF-β1 levels in the culture supernatants were examined by enzyme-linked immunosorbent assay, while pSmad2/Smad3 in culture pellets was analyzed by Western blot, and the expression of Smad2 and Smad3 mRNA was tested by qPCR. Results The collagen, relaxin-2, TGF-β1, and pSmad2/Smad3 protein expression levels were significantly decreased in the CRSwNP group compared with the CRSsNP group ( P < .05). The expression of relaxin-2, Smad2, Smad3, and TGF-β1 mRNA in the CRSsNP group was significantly higher than in the CRSwNP and control groups ( P < .05). Compared with the ex vivo controls, in CRSwNP, the levels of TGF-β1, collagen I, pSmad2/Smad3, Smad2, and Smad3 were markedly decreased after relaxin-2 treatment. However, relaxin-2, collagen I, pSmad2/Smad3, Smad2, and Smad3 were remarkably increased after TGF-β1 treatment. Conclusions The antifibrotic effects of relaxin-2 may play a role in tissue remodeling in CRSwNP, but the detailed mechanism deserves further study.

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Absorption Capability of a 645-nm Diode Laser on Swine Soft Tissue Samples: a Preliminary Study in an Ex-Vivo Model Tissue Samples: a Preliminary Study in an Ex-Vivo Mo

Journal of Dentistry Indonesia ◽

10.14693/jdi.v26i2.1321 ◽

2019 ◽

Vol 26 (2) ◽

Author(s):

Giulia Ghidini ◽

◽

Paolo Vescovi ◽

Marco Meleti ◽

Setti Giacom ◽

...

Keyword(s):

Soft Tissue ◽

Diode Laser ◽

Ex Vivo ◽

Ex Vivo Model ◽

Tissue Samples ◽

Preliminary Study

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Ex vivo model of herpes simplex virus type I dendritic and geographic keratitis using a corneal active storage machine

PLoS ONE ◽

10.1371/journal.pone.0236183 ◽

2020 ◽

Vol 15 (7) ◽

pp. e0236183

Author(s):

Emilie Courrier ◽

Corantin Maurin ◽

Victor Lambert ◽

Didier Renault ◽

Thomas Bourlet ◽

...

Keyword(s):

Herpes Simplex Virus ◽

Herpes Simplex ◽

Virus Type ◽

Herpes Simplex Virus Type ◽

Ex Vivo ◽

Type I ◽

Ex Vivo Model ◽

Active Storage ◽

Simplex Virus

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P048 A NEW MODALITY FOR BIOMECHANICAL VALIDATION OF CLOSURE TECHNIQUES OF LAPAROTOMIES

British Journal of Surgery ◽

10.1093/bjs/znab395.044 ◽

2021 ◽

Vol 108 (Supplement_8) ◽

Author(s):

Floris den Hartog ◽

Dimitri Sneiders ◽

John Vlot ◽

Gert-Jan Kleinrensink ◽

Johannes Jeekel ◽

...

Keyword(s):

Ex Vivo ◽

Tissue Sample ◽

Speckle Pattern ◽

Tensile Load ◽

Suture Technique ◽

Fascial Closure ◽

Ex Vivo Model ◽

Tissue Samples ◽

Pulling Forces ◽

Set Up

Abstract Aim Incisional hernia remains one of the most frequent complications after abdominal surgery. Several closure techniques exist. However, fundamental biomechanical understanding of these techniques and of the differences in clinical outcomes are still lacking. It is thought that distribution of lateral forces on the midline plays a role. Testing in a clinical setting is limited by sample sizes, costs and ethical regulations. We propose a preclinical ex vivo model in which multiple closure configurations can be tested in a controlled setting, eliminating interfering variables existing in previously published, more complex abdominal wall models. Consequently, this allows a valid comparison between closure modalities based on biomechanical merits. Material and Methods The experimental set-up is represented by a vertical tensile load tester, in which a sutured tissue sample is clamped. The tissue samples are covered with a fine, random speckle pattern via miniscule ink droplets. A high-resolution camera captures the speckles as the tissue is subjected to linear pulling forces. Image analysis documenting relative movement of speckles as a means for measuring tissue deformation is performed in ex-vivo tissue samples, resulting in specific objective biomechanical characteristics for each closure configuration. Results Local tissue strain fields are visualized, and compared between closure modalities and correlated to known linear forces applied to the tissue. The latest results will be shared and discussed. Conclusions A new modality for biomechanical evaluation of closure techniques has been developed. Further validation and serial experiments with different closure modalities with and without mesh reinforcement can be performed in order to determine the biomechanically optimal suture-technique for fascial closure.

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Ineffective Erythropoiesis Caused by Phenylhydrazine Activates the Expression of GDF15 in Maturing Erythroblasts.

Blood ◽

10.1182/blood.v114.22.4032.4032 ◽

2009 ◽

Vol 114 (22) ◽

pp. 4032-4032

Author(s):

Toshihiko Tanno ◽

Orapan Sripichai ◽

Seung-Jae Noh ◽

Colleen Byrnes ◽

Emily Riehm Meier ◽

...

Keyword(s):

Caspase 3 ◽

Conflicts Of Interest ◽

Ex Vivo ◽

Annexin V ◽

Refractory Anemia ◽

Type I ◽

Ros Production ◽

Ineffective Erythropoiesis ◽

Ex Vivo Model ◽

Transfusion Therapy

Abstract Abstract 4032 Poster Board III-968 Several types of ineffective erythropoiesis (thalassemia, congenital dyserythropoietic anemia type I, and refractory anemia with ringed sideroblasts) develop anemia and eventually manifest secondary hemochromatosis even in the absence of transfusion therapy. The highly elevated levels of GDF15 in those patients may contribute to iron loading due to suppression of hepcidin. However, the underlying mechanism for high-level expression of GDF15 in association with ineffective erythropoiesis remains vague. Phenylhydrazine (PHZ), which causes hemoglobin denaturation and alpha-globin precipitation, was utilized in CD34+ cultures as an ex vivo model of ineffective erythropoiesis. All experiments were performed in triplicate with cells from three separate human donors. Initial studies were performed to determine the effects of phenylhydrazine upon reactive oxygen species (ROS) production and apoptosis in the erythroblasts. In dosed titrations (0-10 uM), PHZ was added to the culture medium before and after erythroblast hemoglobin accumulation on culture days 3-6 and 11-14, respectively. PHZ addition prior to the accumulation of hemoglobin had little effect on ROS production. In contrast, PHZ added to hemoglobinized erythroblasts resulted in significant and dosed increases in ROS production. In addition, apoptosis cascades that are downstream of ROS production were studied including activation of caspase-3, EGR-1 transcription, p53 stabilization, and phosphatidylserine on the cell surface (detected by Annexin V). There was a dose-dependent increase in caspase-3, p53 stabilization, and Annexin V positive cells that mirrored the ROS production after PHZ treatment only among the more mature erythroblasts. However, the PHZ addition did not cause a significant increase in the nuclear localization of EGR-1. Since GDF15 is a known target of p53, PHZ effects upon GDF15 expression were also measured. Production of GDF15 was not observed on culture days 3-6 in the absence or presence of PHZ. In contrast, dosed increases in GDF15 expression were detected among the hemoglobinized erythroblasts (culture days 11-14) in response to phenylhydrazine (PHZ = 0 uM, GDF15 = 16 ± 3 pg/1×104cells; PHZ = 1 uM, GDF15 = 23 ± 5 pg/1×104cells; PHZ = 5 uM, GDF15 = 48 ± 9 pg/1×104cells [p<0.01]; PHZ = 10 uM, GDF15 = 75 ± 22 pg/1×104cells [p<0.01]). Of note, GDF15 expression was not detected after enucleation in peripheral blood erythrocytes exposed to PHZ despite increased ROS. According to these data, it is proposed that ineffective erythropoiesis may be caused by increased ROS production during the later stages of erythroblast maturation that activates caspase-3, apoptosis and p53-mediated expression of GDF15. Disclosures: No relevant conflicts of interest to declare.

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