Microfluidic systems can potentially improve existing synthetic systems since they allow control and manipulation of liquids on a microscale. Droplet-based approaches are especially suitable due to this method's automation and high throughput capacity.
This article reviews the role of microfluidics in artificial cells´ manufacturing. It also shows you everything you need to start working with this technique.
Artificial Cells Manufacturing
Cells are smart factories where biochemical reactions occur. With the help of enzymes, these reactions produce several substances that keep the organism alive and functioning. That´s why scientists put a lot of effort into developing materials that mimic cells´ functions and characteristics. They successfully manufactured artificial organs and tissues such as the heart, liver, skin, and muscle, .
But besides complex tissues and organs, scientists have turned their attention to something smaller: cells. Many believe artificial cells could replace natural cells in investigating the origins of life. But it doesn´t stop there – it could lead to the establishment of artificial cell factories. Using artificial cells could solve common pitfalls in working with natural cells, such as fragility, difficulty in analysing, and apoptosis, .
Artificial Cells: Fabrication Process
Manufacturing artificial cells involve removing genes from an organism, leaving only those that can sustain the fundamental cellular processes. Another method creates an entire cell from scratch by combining biological and inorganic substances, .
Droplet-based Microfluidics for Vesicles & Artificial Cell Fabrication
The droplet-based microfluidic technique allows researchers to produce droplets with precision and high throughput. This physically and chemically isolated environment offers the perfect conditions for fast reactions to occur with minimal reagent consumption. These characteristics can be valuable when manufacturing vesicles and artificial cells, :
Unicompartmental vesicles: Unicompartmental vesicles are essential tools in the study of drug delivery, diagnostic imaging, and biosensors. Also, encapsulated biomolecules can mimic certain aspects of living cells. This method allows for adjusting the vesicle’s size, lipid composition, membrane, and contents, . Asymmetrical vesicles containing different molecule types have a better endocytosis rate and endosomal escape ability than symmetrical ones. This feature is critical for replicating realistic cell membranes, .
Multi-compartmental vesicles: Multicompartmentalization enables the separation and protection of the intracellular matrix. This feature has inspired scientists to develop multi-compartmental vesicles. Microfluidic methods can generate onion-like vesicles by changing the instability of the oil/water phase emulsion, .
Artificial cells: An artificial cell is a micron-sized system that can mimic a living cell´s morphology and functions. The principal objective is to explore and understand cellular life and fabricate efficient cell factories to catalyze biochemical reactions, .
The advantages of using microfluidics platforms instead of traditional methods for manufacturing artificial cells are, :
Low reagent consumption
Droplet-based microfluidics is particularly suitable for artificial cells fabrication since it enables researchers to produce complex and size controllable droplets, .
For instance, Raghavan and colleagues developed an oil-free water–gas microfluidic technique to create microcapsules via common and inexpensive biopolymers precursors. These microcapsules enabled the encapsulation of biomolecules, colloids, and microbial species to form an artificial cell, similar to eukaryotic cells, [1, 2].
Furthermore, microfluidic devices can generate artificial cells with different shapes, essential to maintain cellular dynamics. For example, one study reported a microfluidic device transforming cell shapes into rods and discs. These synthetic cells had the same physiology and morphology as the living cells, [1, 3].
As we already talked about, artificial cells provide plenty of opportunities in biomedical research. For example, one group created artificial cells with growth and division ability, providing a model for cell proliferation. These models can also be used to study the communication between synthetic and living cells, .
Other possible applications are:
On-site drug delivery in response to a stimulus
Studying biological processes
Synthesis of enzymes and proteins
What do you need to get started?
Droplet microfluidics techniques provide cost-effective and high-throughput analysis. The minimum setup to start your experiments with droplet generation is:
4U Pump (enabling independent control of up to 4 channels) or two–three ExiGo Pumps, depending on the application. The 4U pump is suitable for most droplet generation application: flow-focusing set-ups for water-in-oil droplets including those with 2 aqueous phases. The ExiGo pumps has advantages for applications with chemically corrosive reagents (e.g. toluene) as the sample reservoir can be the glass syringe and chemically inert tubing and connections can be provided.
2x Flow sensors to provide feedback of the flow control of both oil and water phases.
Microfluidic Chip with appropriate geometry creates droplets to ensure droplet size is optimal.
Stable Channel Surface Chemistry to ensure droplet stability.
Surfactant stabilizes the interface between the oil and water phase, giving stability to the droplets.
Oil for continuous phase to improve droplet stability.
Tubing to connect from your pumps to the microfluidic chip
Ai, Y., Xie, R., Xiong, J., & Liang, Q. (2020). Microfluidics for biosynthesizing: from droplets and vesicles to artificial cells. Small, 16(9), 1903940.
A. X. Lu, H. Oh, J. L. Terrell, W. E. Bentley, S. R. Raghavan, Chem. Sci. 2017, 8, 6893
F. Fanalista, A. Birnie, R. Maan, F. Burla, K. Charles, G. Pawlik, S. Deshpande, G. H. Koenderink, M. Dogterom, C. Dekker, ACS Nano 2019, 13, 5439.