The Evolve of Microfluidic Organ on Chips

Today almost everything is possible with the use of the technology everything around us can be easier. Technology such made a big difference in world as the time passes by especially in the medical world. One of the latest and hottest development in the world of medicines is the birth of organ on chips. An organ on chip is a microfluidic cell culture device created with microchip manufacturing methods that contains continuously perfused chambers inhabited by living cells arranged to simulate tissue- and organ-level physiology. By recapitulating the multicellular architectures, tissue-tissue interfaces, physicochemical microenvironments and vascular perfusion of the body, these devices produce levels of tissue and organ functionality not possible with conventional 2D or 3D culture systems. They also enable high-resolution, real-time imaging and in vitro analysis of biochemical, genetic and metabolic activities of living cells in a functional tissue and organ context. This technology has great potential to advance the study of tissue development, organ physiology and disease etiology. In the context of drug discovery and development, it should be especially valuable for the study of molecular mechanisms of action, prioritization of lead candidates, toxicity testing and biomarker identification.

Some of the business company that makes it accessible to found the right chips that you are using in the labs is Corsolutions they are based in New York that truly embodies the users needs. Body-on-a-Chip is an emerging research area that cultures human organ tissue in microdevices to accurately mimic their structure and function. The goal is to develop the best predictive model of human response to therapies, drugs, cosmetics and other chemical compounds. The applications for Body-on-a-Chip are far-reaching.

Organ-on-chips could be the end of Animal Testing

The end of animal testing could finally be near as new smart microchips developed by engineers at the Harvard University promises to render the practice unnecessary. The new technology, aptly called organs-on-chip, is designed to simulate several human organ functions but on a microscale. These microchips can mimic the lungs, the intestines or the heart, making them ideal for testing cosmetics and drugs without using animal subjects and at lesser costs.

The revolutionary concept behind the Human Organs-On-Chip project was awarded the Design of the Year given by the London's Design Museum. It was able to beat out the self-driving car design developed by Google.

"The microdevices have the potential ability to deliver transformative change to pharmaceutical development and human healthcare due to the accuracy at which they emulate human organ-level functions," the developers of the organs-on-chips said.

"They stand to significantly reduce the need for animal testing by providing a faster, less expensive, less controversial and accurate means to predict whether new drug compounds will be successful in human clinical trials."

To create the microchips, the developers first had to produce a small plastic block with microchannels coursing through it. They then lined these tubes using a porous membrane with human cells taken from the lungs and several blood vessels.

This membrane layer is used to separate a solution of white blood cells required to kill off body infections from a space where cells of bacteria are kept.

The membranes are then expanded and contracted in order to allow the white blood cells to reach the bacteria cells and attack them, much like how they destroy infections in the body. Scientists would then be able to use the microchips to test the reaction of this immune system to various infectious diseases.

The design for the organs-on-chips was first conceptualized by Donald Ingber, founder of Harvard's Wyss Institute, and Dan Dongeun Huh, a former Wyss Institute developer, back in 2010.

"This is a big win towards achieving our Institute's mission of transforming medicine and the environment by developing breakthrough technologies and facilitating their translation from the benchtop to the marketplace," Ingber said.

Microfluidics Chips How It is Made

Microfluidic chips are the devices used in microfluidics in which a micro-channels network has been molded or patterned. Thanks to a various number of inlet and outlet ports, these microfluidic instruments allow your fluids to pass through different channels of different diameter, usually ranging from 5 to 500 μm1. The micro-channels network must be specifically designed for your application and the analyses you want to carry out (cell culture, organ-on-a-chip, DNA analysis etc.)

Microfluidic devices such as chips have many advantages as they can decrease your sample and reagent consumption and increase automation, thus minimizing your analysis time2. Such devices allow applications in many areas such as medicine, biology, chemistry and physics3. Three types of materials are commonly used to create microfluidic chips : silicon, glass, and polymers. Each material has its specific chemical and physical characteristics. The choice of the material depends on the needs and conditions of your applications (type of solvant, samples, etc.), the design of the chip you want to obtain and your budget.

For some experiments, a combination of these three materials will be needed to create the desired microfluidic chip:

MICROFLUIDIC CHIPS IN SILICON

Advantages of silicon are its superior thermal conductivity, surface stability and solvent compatibility. However no applications in optical detection can be done due to its optical opacity2, 4.

MICROFLUIDIC CHIPS IN GLASS Glass shares with silicon the same advantages mentioned above. Its well-defined surface chemistries, superior optical transparency and excellent high-pressure resistance2,4 make it a material of choice for many applications. Glass is also biocompatible, chemically inert, hydrophilic and allows efficient coatings. The main hurdle with this material remains its rather high cost, even though prices have been significantly reduced.

MICROFLUIDIC CHIPS IN POLYMERS Polymers offer an attractive alternative to glass and silicon as they are cheaper, robust and require faster fabrication processes4. Many polymers can be used to build chips : Polystyrene (PS), Polycarbonate (PC), Polyvinyl chloride (PVC), Cyclic Olefin Copolymer (COC), Polymethyl methacrylate (PMMA) and Polydimethylsiloxane (PDMS).

PDMS is the material of choice for fast prototyping microfluidic devices. PDMS chips are commonly used in laboratories, especially in the academic community due to their low cost and ease of fabrication. Here are listed main advantages of such chips: Oxygen and gas permeability Optical transparency, robustness Non toxicity Biocompatibility

One of the main drawbacks of PDMS chips is its hydrophobicity. Consequently, introducing aqueous solutions into the microchannels is difficult and hydrophobic analytes can adsorb onto the PDMS surface, thus interfering with analysis. There are now PDMS surface modification methods such as gas phase processing methods and wet chemical methods (or combination of both) to avoid issues due to hydrophobicity2. Another main issue of PDMS chips is that they are non-suitable for high pressure operation as it can alter channels geometry4.

Let Us Know More About Flow Meters

Flow meters is a device used to measure the flow rate or quantity of a gas or liquid moving through a pipe. Flow measurement applications are very diverse and each situation has its own constraints and engineering requirements. Flow meters are referred to by many names, such as flow gauge, flow indicator, liquid meter, etc. depending on the particular industry; however the function, to measure flow, remains the same.

Why do I need a precision flow meter? You might not! Precision flow meters are used to provide accurate monitoring and/or flow control. Some industrial applications require precise calculation of quantity.

What type of flow meter is best? There are no “universal” flow meters which are suitable for all applications. Selecting the proper technology for your application requires writing a flow specification which covers the use of the meter. There are usually trade-offs with each meter type, so knowing the critical specifications will be important. Things you must know:

What Gas or Liquid will be measured? Minimum and maximum flow rates. What are the accuracy requirements? The fluid temperature and viscosity. Fluid compatibility with the materials of construction (See our materials compatibility guide) The maximum pressure at the location. What pressure drop is allowable? Will the meter be mounted in a hazardous location? Is the fluid flow continuous or intermittent?

Materials for Microfluidic Chips Fabrication

Through manipulating fluids using microfabricated channeland chamber structures, microfluidics is a powerful tool to realize high sensitive, high speed, high throughput, and low cost analysis. In addition, the method can establish a well-controlled microenivroment for manipulating fluids and particles. It also has rapid growing implementations in both sophisticated chemical/biological analysis and low-cost point-of-care assays. Some unique phenomena emerge at the micrometer scale. For example, reactions are completed in a shorter amount of time as the travel distances of mass and heat are relatively small; the flows are usually laminar; and the capillary effect becomes dominant owing to large surface-to-volume ratios. In the meantime, the surface properties of the device material are greatly amplified, which can lead to either unique functions or problems that we would not encounter at the macroscale. Also, each material inherently corresponds with specific microfabrication strategies and certain native properties of the device. Therefore, the material for making the device plays a dominating role in microfluidic technologies. In this Account, we address the evolution of materials used for fabricating microfluidic chips, and discuss the application-oriented pros and cons of different materials.

This generally follows the order of the materials introduced to microfluidics. Glass and silicon, the first generation microfluidic device materials, are perfect for capillary electrophoresis and solvent-involved applications but expensive for microfabriaction. Elastomers enable low-cost rapid prototyping and high density integration of valves on chip, allowing complicated and parallel fluid manipulation and in-channel cell culture. Plastics, as competitive alternatives to elastomers, are also rapid and inexpensive to microfabricate. Their broad variety provides flexible choices for different needs. For example, some thermosets support in-situ fabrication of arbitrary 3D structures, while some perfluoropolymers are extremely inert and antifouling. Chemists can use hydrogels as highly permeable structural material, which allows diffusion of molecules without bulk fluid flows. They are used to support 3D cell culture, to form diffusion gradient, and to serve as actuators. Researchers have recently introduced paper-based devices, which are extremely low-cost to prepare and easy to use, thereby promising in commercial point-of-care assays.

In general, the evolution of chip materials reflects the two major trends of microfluidic technology: powerful microscale research platforms and low-cost portable analyses. For laboratory research, chemists choosing materials generally need to compromise the ease in prototyping and the performance of the device. However, in commercialization, the major concerns are the cost of production and the ease and reliability in use. There may be new growth in the combination of surface engineering, functional materials, and microfluidics, which is possibly accomplished by the utilization of composite materials or hybrids for advanced device functions. Also, significant expanding of commercial applications can be predicted.

Understanding More What is PDMS

Polydimethylsiloxane or shortly known as PDMS belongs to a group of polymeric organosilicon compounds that are commonly referred to as silicones. PDMS is the most widely used silicon-based organic polymer, and is particularly known for its unusual rheological or flow properties. PDMS is optically clear, and, in general, inert, non-toxic, and non-flammable. It is also called dimethicone and is one of several types of silicone oil (polymerized siloxane). Its applications range from contact lenses and medical devices to elastomers; it is also present in shampoos as dimethicone makes hair shiny and slippery, food antifoaming agent, caulking, lubricants, kinetic sand , and heat-resistant tiles.

PDMS is viscoelastic, meaning that at long flow times (or high temperatures), it acts like a viscous liquid, similar to honey. However, at short flow times (or low temperatures), it acts like an elastic solid, similar to rubber. In other words, if some PDMS is left on a surface overnight (long flow time), it will flow to cover the surface and mold to any surface imperfections. However, if the same PDMS is rolled into a sphere and thrown onto the same surface (short flow time), it will bounce like a rubber ball.

Although the viscoelastic properties of PDMS can be intuitively observed using the simple experiment described above, they can be more accurately measured using dynamic mechanical analysis. This method requires determination of the material's flow characteristics over a wide range of temperatures, flow rates, and deformations. Because of PDMS's chemical stability, it is often used as a calibration fluid for this type of experiment.

PDMS can be used to fabricate a myriad of structures through soft lithography. The process of soft lithography consists of creating an elastic stamp which enables the transfer of patterns only a few nanometers in size. Furthermore a single master mold can be used to fabricate numerous PDMS devices.

The process of fabricating a microfluidic device from PDMS is relatively simple. To start, the PDMS two-part kit, consisting of the base and the cross-linking agent are mixed. The mixing ratios and curing procedures used determine the mechanical, chemical and optical properties of the final device. Upon mixing, the PDMS must be degassed under vacuum. Next the liquid pre-polymer is poured over a previously fabricated master mold. The master molds used to fabricate PDMS devices are most commonly made from SU-8. However metal, plastic and even 3D printed maters are now gaining popularity. Once the PDMS is poured into the mold, the liquid pre-polymer conforms to the shape of the mold, replicating the features.

Knowing Corsolutions Microfuidic Connectors

Understanding the word itself connectors are used in connecting two objects to join or fasten (two things together, or one thing with or to another). Corsolutions is one of the new company that built and design your prototype microfluidics devices that you need.

If you are looking for connectors why choose Corsolutions Connectors?

Rapidly established, user-friendly connections Connections are non-permanent Allows for tighter density of microchip ports Wide variety of fittings or adapters can be used As the approach does NOT use adhesion, fittings are reusable Connections are compatible with all substrate materials including PDMS, glass, silicon and plastics Connections remain leak-tight at greater than 500 psi Highly reproducible connections Can seal at any location on the surface or side of the device Top-side and back-side alignment Connections are lower dead-volume than conventional approaches Can be used for final performance assessment, and for chemistry treatment of devices during fabrication

How it Works Mount The connectors mount to a flat surface with either a screw (1/4-20 or M6) or a magnet.

End Attachment The end attachment portion of the connector is specific for a tubing or adapter size. This attachment is removable and can be easily exchanged. Please see below for example end attachments.

Compression Seal The connector makes a compression seal between a gasket, held by the connector arm, and the microdevice. The amount of compressive force applied can be adjusted. Depending on the microdevice substrate material, the compression seal can remain leak tight at greater than 500 psi. Watch the video below to understand more about the product.