Factors affecting human islet cell quality

The islets of Langerhans are the regions of the pancreas that contain its endocrine (i.e., hormone-producing) cells. Discovered in 1869 by German pathological anatomist Paul Langerhans, the islets of Langerhans constitute approximately 1% to 2% of the mass of the pancreas. There are about one million islets distributed throughout the pancreas of a healthy adult human. Each is separated from the surrounding pancreatic tissue by a thin fibrous connective tissue capsule. The islets of Langerhans contain beta cells, which secrete insulin, and play a significant role in diabetes.

Islets are widely used for transplantation to restore beta cell function from diabetes, offering an alternative to a complete pancreas transplantation or an artificial pancreas. Because the beta cells in the islets of Langerhans are selectively destroyed by an autoimmune process in type 1 diabetes, islet transplantation is a means of restoring physiological beta cell function in patients with type 1 diabetes.

Human Islets for Research (HIR)™ are primary human islets processed from organ donor pancreases that have been approved for research but not for clinical transplantation of either the  pancreas or the isolated islets. HIR™ are obtained in a proprietary process of pancreas digestion and islet purification that results in uniformly high quality HIR™ for delivery to diabetes  investigators. Quality Control (QC) testing is routinely performed prior to release to assure uniform quality and function of these islets available for research. [Read more…]

Cellular models to study the Cardiac System (part II)

In a previous post, I introduced several models to study the cardiac human system. This first post introduced human aortic, brachiocephalic, carotid artery and coronary artery cells isolated by Cell Applications Inc. Here is the second part of this inventory of cellular models to study the human cardiac system, where I’ll be highlighting human internal thoracic artery, pulmonary artery, subclavian artery cells, cardiac fibroblasts and cardiomyocytes.

Later on, I’ll conclude this series by part III, referring to animal cellular models for studying the cardiac system. But let’s now concentrate on today’s topic! [Read more…]

Cellular models to study the cardiac System (part I)

In this post, I’d like to  introduce human aortic, brachiocephalic, carotid artery and coronary artery cells isolated by Cell Applications Inc. In a future post, I’ll be highlighting human internal thoracic artery, pulmonary artery, subclavian artery cells and cardiomyocytes (now published here).

After taking a look at several cell types as models for studying different aspects of cardiovascular functions and diseases, I’ll cover some recently published results highlighting the importance of securing your primary cells sourcing.

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Formation of Mesenchymal Tissues in Alvetex® Scaffold

The Alvetex®Scaffold is a novel substrate that enables a solution for simple and routine 3D culture. It is composed of a highly porous polystyrene scaffold that has been engineered into a 200 micron thick membrane to enable entry of cells and efficient exchange of gases and solutes. Cells enter the fabric of the scaffold, retain their natural 3D structure, and form close 3D interactions with adjacent cells. Unlike conventional 2D culture, cells in Alvetex®Scaffold do not grow as monolayers and do not undergo the flattened shape transition that can result in aberrant changes to gene and protein expression and consequently cellular function.

Mesenchymal stem cells (MSCs) are adherent multipotent cells derived from tissue such as bone marrow and which possess the ability to differentiate in vitro into a number of tissue types including bone, cartilage and muscle [1].

In this post, we demonstrate that MSCs extracted from the bone marrow of adult rats can be successfully cultured in 3D in Alvetex®Scaffold and induced to differentiate into osteogenic and adipogenic derivatives more efficiently than their 2D counterparts. We also report bone formation and the production of extracellular matrix by MG63 cells which represent an established cell line derived from a human osteosarcoma. The data generated here is supported by peer-reviewed literature [2,3] and clearly shows that Alvetex®Scaffold promotes enhanced in vitro differentiation. [Read more…]

Case study: 3D Cancer Cell Cytotoxicity in vitro Assessment

Nowadays in Cancer research, there is a strong need for three-dimensional (3D) in vitro experimental approaches that mimick as much as possible the in vivo tumour ecosystem. In addition to solving issues related to animal models, these in vitro 3D models allow precise tuning of experimental design when investigating cancer cell biology but also, compound screening and disease modelling. In this post, we’ll take a look at the growth of the popular breast cancer cell line, MCF-7, using Alvetex®Scaffold technology (Reinnervate – a ReproCell company) to create a 3D structure that closely resembles the structure of tumour tissues grown in vivo.

[Read more…]

Cell counting made easy!

After you’ve read this post, I hope that you’ll agree that what the title of the post announces is the right assumption. How? Read on!

I invite you to take a look at Cyto-X, which is a ready-for-use cell viability reagent for proliferation and cytotoxicity assays. When added to cell culture, a highly water-soluble tetrazolium salt is reduced by dehydrogenases in live cells to form an orange colored formazan product that is soluble in culture medium. The amount of formazan is directly proportional to the enzymatic activity of dehydrogenases and the number of living cells.

With its high sensitivity and low cytotoxicity, Cyto-X outperforms traditional assays using other tetrazolium salts such as MTT, XTT, MTS or WST-1.

Here are 3 good reasons to try Cyto-X Colorimetric cell counting reagent…

1. It’s more sensitive

 

Cyto-X 1

 

Left: Human Dermal Fibroblasts (HDF) were seeded at different concentrations. Cells were counted the next day using the Cyto-X (blue) and MTT (orange) assays.
Right: Bovine Aortic Endothelial Cells (BAOEC) were treated with staurosporine for 16 hours. Cell number was determined by Cyto-X and MTT assays.

 

2. It’s less toxic

Cyto-X 2

Left: Cyto-X was added to Human Umbilical Vein Endothelial Cells (HUVEC) for 24 hours. Following the Cyto-X cell counting assay, HUVEC are still proliferating and capable of uptaking DiL-Ac-LDL, demonstrating HUVEC are metabolically active, and that downstream applications are possible.
Right: By contrast, toxic formazan is formed after the MTT assay and HUVEC are dead.

 

3. It’s user friendly: fewer steps & less waiting time

Cyto-X 3

So, doesn’t this make cell counting easy? I could also claim “Cell counting made easy and inexpensive!”. Not only is this protocol quicker, it also uses less reagents vs. MTT (no phenol-red medium, no extraction solution, no wash solution, etc) and is as cheap as 0.36 € per test point.

Convinced? Leave your comments or get in touch below!

A polystyrene scaffold for 3D endocervix model

In this published work, Novel Three Dimensional Human Endocervix Cultures respond to 28-day hormone treatment (1) , the authors’ goal was to develop a robust three-dimensional (3D) endocervix model that was a reliable representation of the in vivo tissues and to identify the physiological responses to changing levels of steroid hormones during a 28-day time period. Human endocervical cells were grown on polystyrene scaffolds and the morphologic and hormonal responses of cultured cells were assessed in response to fluctuating levels of estradiol (E2) or progesterone (P4). [Read more…]

Tips for primary cell culture

Functionality and viability of primary cells can be impaired by incorrect thawing procedures, storage or culture conditions. It’s generally admitted that applying the same protocols as for cell lines leads will lead to bad cell quality. Well, based on our experience with primary cells, here are a few tips you can follow to ensure you get the best performance.

[Read more…]

Physioxia or Hypoxia: what it’s all about

Cell culture under oxygen controlled conditions: an improvement towards more predictive results

Oxygen concentration in tissues is a key factor for cell and organ survival. In normal conditions, partial oxygen pressure (pO2) results in the balance between oxygen delivery and its consumption. Oxygen is transported, in mammals, by circulating red blood cells. Partial oxygen pressure in tissues varies widely, depending on their respective metabolic requirements and their functional status. In normal physiological conditions,  partial oxygen pressure is called physioxia. Any alteration of tissue environment leading to a decrease in partial oxygen pressure is called hypoxia. Hypoxic conditions have been observed in many different pathological situations like tumor development, obesity or transcient ischemia. [Read more…]

tebu-bio sponsors Pasteur Institute’s Advances in Stem Cell Biology Course 2014

Pasteur Institut LogoFor the second year running,  tebu-bio is proud to be partner of the Pasteur Institute during the “2nd Advances in stem cell biology (ASCBC )” course (June 30 – July 12, 2014).

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