A new study demonstrates the role of a new method in delivering microfluidic platforms for 3D printing quickly and cheaply. Scientists from the University of Huddersfield published their research in the “Advanced Healthcare Materials” journal on April 25, 2023.
Microfluidics and its applications in regenerative medicine
Microfluidics is a science that focuses on studying fluid behavior in microchannels as well as developing technologies to create microchambers or microchannels through which fluids flow. In medicine, these technologies are used in regenerative medicine to develop microenvironments for cellular and tissue culture, drug delivery systems, and 3D tissues to replace damaged ones.
This passage provides an overview of the new manufacturing process to create microfluidic devices using Material Extrusion Additive Manufacturing (MEAM). The process involves (a) directly controlling the 3D printer to (i) apply complex passive mixer designs using the CONVEX design approach, which allows (ii) the creation of a single layer of ABS filament with a specific cross-sectional area. (iii) These MEAM microchannels are then embedded into a PDMS matrix for curing. (iv) Once cured, the PDMS microfluidic devices are cleaned with acetone to dissolve the ABS. The CONVEX design approach (bi-iii) results in highly consistent microchannels with widths ranging from 100-400 µm (with less than 10% deviation from the design widths) and (iv) minimal surface roughness. All four passive mixer designs (ci-iv) can be used as modular units, offering flexibility and scalability with high mixing properties, as demonstrated by (v) experimental data, (vi) computational fluid dynamics (CFD), and (vii) real-time imaging. The MEAM-enabled microfluidic device has potential applications in regenerative medicine, such as (d) (i) in situ mixing of two fluids to create solid fibers, (ii) generating uniform droplets, (iii) extruding multi-materials with dynamic control of channel widths, and (iv) creating anisotropic multi-layer structures with specific diameters and shapes. The potential of the MEAM-enabled microfluidic device in 3D bioprinting is demonstrated by extruding 30 wt.% Pluronic through a 400 µm channel to create a 2D grid-like structure.
Microfluidic bio-fabrication is an expensive and lengthy process. Although its applications in regenerative medicine have shown great promise, its usage in regenerative medicine remains limited for now due to the associated high cost and its lengthy development process.
Challenges of the conventional methods to develop microfluidic devices
Scientists noted many challenges associated with previously used methods for manufacturing microfluidic devices. They concluded that previous methods are resource intensive, expensive, and difficult to implement swiftly. They also mentioned that the automation of previously used techniques and the utilization properties of microfluidics like mixing different fluids and the flow rate of fluids are also significant challenges.
What did the researchers aim to do?
To address the above-mentioned challenges, scientists aimed to develop microfluidic devices which can be more cost-effective, take less time to develop, and possess a range of characteristics favoring different biochemical properties that makes them suitable to be used for a variety of purposes.
How did they develop the microfluidic devices?
In the published study, scientists used a novel technique to develop microfluidic devices which mimic arteries and arterioles. They developed microstructures such as solid fibers and core-shell hollow structures. Utilizing an inexpensive and swift production approach, the researchers developed variable-width zigzag design microfluidic devices. They employed continuous varied extrusion (CONVEX) to develop these materials.
How is the current method better?
According to the researchers, the CONVEX approach allows the development of versatile designs with varied strengths while keeping the production costs to a fraction of that of traditional approaches being used. Furthermore, the scientists demonstrated the versatility of the materials by showing adequate mixing of fluids in the microenvironment and increased viability of cells at different intervals.
What do the scientists think about their research?
Researchers believe that this development shows great promise to develop microfluidic devices more efficiently and cheaply. As shown by the researchers, the developed materials allow rapid mixing of fluids so their mixing properties also present a significant improvement on the previous methods.
Scientists also think that their demonstration will open doors for the high-value production of microfluidic devices by employing these swift manufacturing methods. They believe that this will simplify the process of development of bio-fabrication and it will also reduce the production costs significantly.
What should future studies explore?
In this study, scientists developed microfibers ranging in channel widths from 100 micrometers to a few millimeters. So, they urge other researchers to explore the development of more microfluidic devices having channel widths below 100 micrometers. They hope that this will allow the development of channels mimicking real capillaries. The researchers also believe that the CONVEX approach will open new doors in regenerative medicine.
Significance
This study shows that microfluidic devices can be manufactured cheaply and quickly and possess versatile properties that can advance their development in the future.
There is a significant need for artificially developed tissues and organs. Conventional organ transplantation requires long waiting lists, risk of infection, and a rigorous course of immunosuppression. By showing that tissues can be engineered in a timely and cost-effective fashion, this study opens new doors for the development of artificial tissues. This study also creates new opportunities for applications of microfluidic devices in developing tissue and organ cultures, the development of rapid drug delivery systems, and other biochemical developments.
References
Moetazedian, A., Candeo, A., Liu, S., Hughes, A., Nasrollahi, V., Saadat, M., Bassi, A., Grover, L. M., Cox, L. R., & Poologasundarampillai, G. (2023). Versatile Microfluidics for Biofabrication Platforms Enabled by an Agile and Inexpensive Fabrication Pipeline. Advanced Healthcare Materials. https://doi.org/10.1002/adhm.202300636
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