scholarly journals Evaluation of bone formation on orthopedic implant surfaces using an ex-vivo bone bioreactor system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rupak Dua ◽  
Hugh Jones ◽  
Philip C. Noble
Keyword(s):  
Culture System ◽  
Ex Vivo ◽  
Calcium Phosphates ◽  
Wire Mesh ◽  
Bioreactor Culture ◽  
Static Culture ◽  
Group 4 ◽  
The Matrix ◽  
Bioreactor System ◽  
Fiber Mesh

AbstractRecent advances in materials and manufacturing processes have allowed the fabrication of intricate implant surfaces to facilitate bony attachment. However, refinement and evaluation of these new design strategies are hindered by the cost and complications of animal studies, particularly during early iterations in the development process. To address this problem, we have previously constructed and validated an ex-vivo bone bioreactor culture system that can maintain the viability of bone samples for an extended period ex-vivo. In this study, we investigated the mineralization of a titanium wire mesh scaffold under both static and dynamic culturing using our ex vivo bioreactor system. Thirty-six cancellous bone cores were harvested from bovine metatarsals at the time of slaughter and divided into five groups under the following conditions: Group 1) Isolated bone cores placed in static culture, Group 2) Unloaded bone cores placed in static culture in contact with a fiber-mesh metallic scaffold, Group 3) Bone cores placed in contact with a fiber-mesh metallic scaffold under the constant pressure of 150 kPa, Group 4) Bone core placed in contact with a fiber-mesh metallic scaffold and exposed to cyclic loading with continuous perfusion flow of media within the ex-vivo culture system and Group 5) Bone core evaluated on Day 0 to serve as a positive control for comparison with all other groups at weeks 4 and 7. Bone samples within Groups 1–4 were incubated for 4 and 7 weeks and then evaluated using histological examination (H&E) and the Live-Dead assay (Life Technologies). Matrix deposits on the metallic scaffolds were examined with scanning electron microscopy (SEM), while the chemical composition of the matrix was measured using energy-dispersive x-ray spectroscopy (EDX). We found that the viability of bone cores was maintained after seven weeks of loading in our ex vivo system. In addition, SEM images revealed crystallite-like structures on the dynamically loaded metal coupons (Group 4), corresponding to the initial stages of mineralization. EDX results further confirmed the presence of carbon at the interface and calcium phosphates in the matrix. We conclude that a bone bioreactor can be used as an alternate tool for in-vivo bone ingrowth studies of new implant surfaces or coatings.

Expansion of Hematopoietic Stem Cells (HSC) from Cord-Blood (CB) Derived Mononuclear Cells (MNC) in Cytokine-Free Environment Using Mesenchymal Cells Spatial Co-Culture System.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2565-2565
Author(s):  
Shai Meretzki ◽  
Ora Burger ◽  
Osnat Merom-Jacov ◽  
Avinoam Kaduri ◽  
Jacob M. Rowe ◽  
...  
Keyword(s):  
Culture System ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Current System ◽  
Growth Media ◽  
Great Loss ◽  
Hematopoietic Stem ◽  
Efficient System ◽  
Bioreactor System ◽  
Free Environment

Abstract In situ, HSCs are intimately associated with discrete spatially organized niches within the bone marrow, which are part of the “hematopoietic inductive microenvironment” (HIM). The HIM provides a range of molecular signals that collectively control HSC differentiation and self-renewal. This process is mediated via cell-cell and cell-ECM molecular contacts or through specific factors synthesized and secreted by mesenchymal stromal cells (MSC). Current strategies aimed at ex vivo expansion of transplantable HSC have so far been met with limited success. Most attempts to expand HSC ex-vivo are based on using monolayers of MSC as a supportive tier or growth media supplemented with blend of cytokines. failure to support long-term maintenance and expansion of human HSC on MSC monolayers could be associated with inadequate physical architecture of the culture systems which does not reflect the natural 3-D growth conditions present within the BM-HIM. The other method based on supporting the Hematopoietic cells proliferation by a blend of cytokines, is proven routine but post transplantation marrow replenishment is currently unsatisfactory and chromosomal epigenetic modifications may be introduced into progeny cells. Using the PluriX™ bioreactor, we had previously demonstrated that spatial co-cultures of MSC and HSCs provide an efficient system for the expansion of HSCs from CB CD34+ selected cells in cytokine-free environment. Over the past years, attempts to expand HSCs mostly employed CD34+ selected cells. However, these cells may not represent the earliest HSCs and the immunomagnetic selection protocols are costly, time consuming and associated with great loss of source cells. A theoretical approach to overcome both hurdles is by using non-selected MNC as the founding population of HSC. Following our ability to expand HSCs from CD34+ selected cells, we now demonstrate the capacity of the 3-D HSC MSCs co-culture system within the PluriX™ bioreactor system to expand HSCs using MNC as HSCs source. Primary Human marrow-derived MSCs were grown on 3-D carriers within the PluriX™bioreactor system. When the MSCs cultures reached high density (3*106–8*106 cells/ml) CD34+ selected cells or MNC were plated onto them. Within 7–14 days, the population of CD34+ and CD34+CD38− cell were expanded irrespective of the HSCs founding source. However, during this period of time the absolute expansion magnitude was greater when MNC rather than CD34+ selected cells were used to drive the process. The enrichment rate of CD34+cell from MNC and CD34+ selected cells was 20–100 vs. 5–20 fold, respectively. Under same conditions, the enrichment of the earlier CD34+CD38− cells was 40–50 vs. up to 10 fold for the same cell populations. In-conclusion, the spatial co-cultures of MSC and HSC within the PluriX™ bioreactor have been shown to form a potent HSCs expansion system in non-supplemented cytokine environment. The capacity of this practice is improved when MNCs, instead of CD34+ selected cells, serve as the originating population for HSCs. It is conceivable that the efficiency of this system is based upon selective adherence between HSCs and the hematopoietic niches within the MSCs 3-D cultures. As such, upscale of the current system could become attractive method for HSCs expansion.

Correlation of γ-radioactivity and Scanning Electron Microscopy in measurement of retention of 111Indium-labeled canine endothelial cells on synthetic vascular grafts

1989 ◽  
Vol 47 ◽  
pp. 886-887
Author(s):  
E.J. Prendiville ◽  
S. Laliberté Verdon ◽  
K. E. Gould ◽  
K. Ramberg ◽  
R. J. Connolly ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ex Vivo ◽  
Vascular Grafts ◽  
Retention Data ◽  
Vascular Prostheses ◽  
Group 4 ◽  
Human Fibronectin ◽  
Insufficient Time ◽  
Group 3 ◽  
Group 2

Endothelial cell (EC) seeding is postulated as a mechanism of improving patency in small caliber vascular grafts. However the majority of seeded EC are lost within 24 hours of restoration of blood flow in previous canine studies . We postulate that the cells have insufficient time to fully develop their attachment to the graft surface prior to exposure to hemodynamic stress. We allowed EC to incubate on fibronectin-coated ePTFE grafts for four different time periods after seeding and measured EC retention after perfusion in a canine ex vivo shunt circuit.Autologous canine EC, were enzymatically harvested, grown to confluence, and labeled with 30 μCi 111 Indium-oxine/80 cm 2 flask. Four groups of 5 cm x 4 mm ID ePTFE vascular prostheses were coated with 1.5 μg/cm.2 human fibronectin, and seeded with 1.5 x 105 EC/ cm.2. After seeding grafts in Group 1 were incubated in complete growth medium for 90 minutes, Group 2 were incubated for 24 hours, Group 3 for 72 hours and Group 4 for 6 days. Grafts were then placed in the canine ex vivo circuit, constructed between femoral artery and vein, and subjected to blood flow of 75 ml per minute for 6 hours. Continuous counting of γ-activity was made possible by placing the seeded graft inside the γ-counter detection crystal for the duration of perfusion. EC retention data after 30 minutes, 2 hours and 6 hours of flow are shown in the table.

Establishment of a Novel Intervertebral Disc/Endplate Culture Model: Analysis of an Ex Vivo In Vitro Whole-Organ Rabbit Culture System

Spine ◽  
2006 ◽  
Vol 31 (25) ◽  
pp. 2918-2925 ◽  
Author(s):  
Daniel Haschtmann ◽  
Jivko V. Stoyanov ◽  
Ladina Ettinger ◽  
Lutz -P. Nolte ◽  
Stephen J. Ferguson
Keyword(s):  
Intervertebral Disc ◽  
Culture System ◽  
Ex Vivo ◽  
Model Analysis ◽  
Culture Model

scholarly journals An Ex vivo Culture System to Study Thyroid Development

10.3791/51641 ◽  
2014 ◽  
Author(s):  
Anne-Sophie Delmarcelle ◽  
Mylah Villacorte ◽  
Anne-Christine Hick ◽  
Christophe E. Pierreux
Keyword(s):  
Culture System ◽  
Ex Vivo ◽  
Thyroid Development

DESIGN OF AN EX-VIVO VESSEL CULTURE SYSTEM FOR THE STUDY OF EARLY ARTERIALIZATION PHENOMENA IN HUMAN SAPHENOUS BYPASS GRAFTS

2012 ◽  
Vol 45 ◽  
pp. S151
Author(s):  
Marco Piola ◽  
Monica Soncini ◽  
Francesca Prandi ◽  
Maurizio Pesce ◽  
Gianfranco Beniamino Fiore
Keyword(s):  
Culture System ◽  
Ex Vivo ◽  
Bypass Grafts

Establishing an ex vivo culture system for normal pancreatic tissue

Pancreatology ◽  
2014 ◽  
Vol 14 (3) ◽  
pp. S120-S121
Author(s):  
Carlos Fernández Moro ◽  
Sougat Misra ◽  
Soledad Pouso ◽  
Marita Wallenberg ◽  
Rainer Heuchel ◽  
...  
Keyword(s):  
Culture System ◽  
Ex Vivo ◽  
Pancreatic Tissue ◽  
Normal Pancreatic Tissue ◽  
Ex Vivo Culture

Bench-Top Validation Tests for Tissue-Engineered Arteries

2000 ◽  
Author(s):  
Shawn Chin Quee ◽  
Hai-Chao Han ◽  
David N. Ku
Keyword(s):  
Organ Culture ◽  
Culture System ◽  
Comprehensive Evaluation ◽  
Ex Vivo ◽  
Vascular Grafts ◽  
Living System ◽  
Organ Culture System ◽  
Flow Pressure ◽  
Validation Tests

Abstract Standard tests are needed for evaluating and comparing the mechanical and biological functions of tissue engineered arteries and other vascular grafts. We propose an ex vivo organ culture system as a living system for testing tissue-engineered vascular grafts. This bench-top organ culture system mimics the physiological environment of arteries including the flow, pressure, and the axial stretch. Arterial mechanical properties and physiologic functions including compliance, burst pressure, and contractile functions can be assessed before an expensive long-term animal test is initiated. Test results of natural arteries indicate that organ culture is a valid model for comprehensive evaluation of tissue-engineered vascular grafts.

Axial Stretch Increases Cell Proliferation in Arteries in Organ Culture

2000 ◽  
Author(s):  
Hai-Chao Han ◽  
Raymond P. Vito ◽  
Kristin Michael ◽  
David N. Ku
Keyword(s):  
Cell Proliferation ◽  
Smooth Muscle ◽  
Organ Culture ◽  
Vascular Function ◽  
Culture System ◽  
Carotid Arteries ◽  
Ex Vivo ◽  
Axial Stretch ◽  
Organ Culture System ◽  
Physiological Flow

Abstract To study the effect of axial stretch on vascular function and wall remodeling, porcine carotid arteries were cultured under conditions of physiological flow and elevated axial stretch in an ex vivo organ culture system. Smooth muscle cell proliferation was measured by bromodeoxyuridine index. Results showed that cell proliferation was significantly increased in the highly stretched arteries when compared to the normally stretched arteries. This may indicate the feasibility of stimulating new arterial growth by stretching natural arteries.

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