Microfluidics: Chemotaxis and ADVANTAGES
it is known microfluidics nowadays is revolutionizing the way the motile behaviour of cells are studied.
It has enabled observations at high spatial and temporal resolution is carefully controlled microenvironments.
Taking into account both of the parts, chemotaxis and microfluidics, there are some advantages when using them two together:
– Presents experimental challenges that are not observed on chemotaxis studies of surface-adherent cells.
– Generate steady, arbitrarily shaped chemical gradients.
– Unique control over the chemoattractant gradient and the migration environment of cells.
– Provide spatial and temporal control over a reproducible chemical environment.
– Enables building well defined and stable chemical gradients at cellular length scales.
– Provide a platform for quantifying cellular responses at cellular and molecular levels.
Microfluidics Application: Chemotaxis
When an organism moves in response to a chemical stimulus it is said that Chemotaxis has happened.
Due to some chemicals that are in the environment the organisms, such as Somatic cells, bacteria, single-cell or multicellular organisms, direct their movements.
When the chemotaxis movements occur toward a higher concentration of the chemical, it is said that is a positive movement.
On the contrary, when the movement is done in the opposite direction, toward the lowest concentration, it is said that is a negative movement.
In addition, if it is nondirectional or randomly directed, the chemotaxis will be called Chemokinesis.
Chemotaxis is done with two independent chemoattractants.
Even if they are independent, we can say that they are interrelated processes-motility and directionality and both of them are regulated by extracellular stimuli.
Electrophoresis using Microfluidics – Main Advantages
Advantages of using electrophoresis with Microfluidics:
1. Improved Diagnosis, simplified diagnostic procedures, faster treatment and results.
2. Simplicity; Fast and easy technique.
3. Low cost material.
Electrophoresis and Microfluidics
Electrophoresis is an analytical method which is applied for the separation and characterization of proteins, nucleic acids and subcellular-sized particles such as viruses and small organelles.
Its principle is that the charged particles of a sample migrate in an applied electrical field.
Electrophoresis of positively charged particles (cations) is called cataphoresis, and on the other hand, electrophoresis of negatively charged particles (anions) is called anaphoresis.
Electrophoresis is a technique used in laboratories to separate macromolecules based on size.
Flow Cytometry : Advantages of using Microfluidics
Positive aspects about Flow Cytometer based on Microfluidics:
1. To have a high purity and recovery for the sorted cell population.
2. To sort based on an intracellular characteristic in which magnetic beads would not have access.
3. To sort cell labelled with fluorescent probes for nuclear or other intracellular targets.
4. To have information about cell surface molecules.
5. To sort different receptors even if they are low in density.
6. To sort cells according to absence, density or presence of the receptors.
Flow Cytometry using Microfluidics
Flow cytometry is a laser-based technology used in cell counting, cell sorting, biomarker detection or protein engineering.
By suspending cells and passing these suspending cells by passing them using an electronic detection machine, flow cytometry is done.
This technique allows making simultaneous analysis of the different characteristics of the more than a thousand particles per second.
This technique is usually used in the diagnosis of health disorders, in most of the cases blood cancers, but it is used in many medical trials, such as to sort particles according to their properties or purify populations of interest.
Microfluidic Application: Organ-on-a-Chip
Advantages of Organ-on-a-chip with microfluidics:
1. 3-D tissue structures look like actual organ physiology.
2. They provide better simulation, which means it is more accurate.
3. For scientist, they can watch the chips in real time and in high resolution.
4. Early effectiveness and safety identification.
Microfluidic Manufacturing Technique: CNC Micromachining
CNC Micromachining is defined as the removal of material at micro level.
During the last year the interest over the micro machining technology has increased.
Due to this, every manufacturing and industry segment has started to work, segments such as aerospace, automotive world or medical appliances.
Even , nowadays, there are still several technical challenges the potential for product miniaturization continues to grow.
The micromachining technologies involves to work with features smaller than 0,001”, that is why, it is necessary to work with accuracy in the 0,0001” or less range, using always cutters smaller than 1/8 or about 3mm. It takes significant speed to effectively use such small-diameter tools, and the machines have to be, as said before, very accurate.
Taking into account the microfluidic field of technology, we can say that micromachining can be used in this field, because recent developments in microfabrication enables the integration of hard and soft structures, making possible to control the microfluidic systems structures. This structures can be applied to drug delivery.
Moreover, there is a manufacturing method which involves laser micromachining for the structure of microfluidic channels in a thin metallic sheet.
It is important to say that some polymers are better to use over silicone when building microfluidic devices because they have biocompatible properties as well as cheapness. Also, using micromachining it is possible to make fewer processing steps than using the conventional way.
Microfluidics Application: Organ-on-a-Chip
Organ on a Chip is a type of artificial organ which simulates the activities, mechanics and physiological response of the entire organs and organ systems.
Moreover, it is a flexible polymer multi-channel 3-D microfluidic cell culture chip, and the union of lab -on-chips and cell biology has enabled the study of human physiology in an organic-specific context.
These types of chips are used to potentially accelerate drug discovery, reduce drug-development costs, to create a future of personalized medicine to treat a wide variety of diseases, such as cancer, pulmonary thrombosis and asthma.
Furthermore, these type of microchips are much more realistic models of the human body comparing with the flat layers of cells grown in petri dishes.
Microfluidics Application: Cell Sorting
Cell sorting consists on separating cell according to their properties.
These properties are of different types, such as intracellular (inside the cell) or extracellular (outside the cell).
The properties worked in this type of separations include DNA, RNA, protein molecule, morphology, size or shape.
Furthermore, there are some different types of cell sorting.
There are two main types when cell sorting. As said before, these techniques, that are called flow cytometry and magnetic bead separation, are used to separate cells into different population.
The biggest difference between these two methods is that flow cytometry sorts cells one by one, while magnetic bead separation works on all cells at once. Although both methods are efficient, it is better to know their relative strenths and weaknesses to choose among them.
The importance of cell sorting:
As known, cells are basic structural and functional unit of all living organism, that is why the ability to isolate and sort different cell types within organs and tissues has led to many established principles in medicine and physiology.
On one hand, and taking into account the research field, the ability to separate cells into distinct populations enables the study of individual cell types isolated form the heterogeneous population without contamination from other cell types. This technology enables research in areas as varied as regenerative medicine, cancer therapy and HIV pathogenesis.
Moreover, in terms of clinical usage, it is possible to introduce the enriched cell populations to a patient who has a clinical need for those cells, and it also enables the enumeration of cells within an individual’s blood system ad can help on the repopulation of the immune system.