Biology subjects

Mason, H. G.

Publications and source records attributed to Mason, H. G..

3 recordsLinked to original sources

bioRxiv2025

Rapid Prototyping of Microfluidic Devices with Stereolithographic 3D Printing

3D printing has become a prevalent technology in many fields such as manufacturing, architecture, and electronics. This additive manufacturing technique is also widely used for biomedical research and clinical applications to prototype or assemble biomedical devices and tools. 3D printing-based strategies for biocompatible materials offer greater design flexibility, enhanced versatility, and faster results than traditional fabrication techniques, advantages that could be especially beneficial to the development of microfluidic chips. The ability to simply and efficiently produce new chip molds from computer aided design (CAD) models would significantly transform the development process and expand its accessibility by removing the need for more complex and expensive lithography methods. However, with standard processing strategies, the use of 3D printed molds for casting functioning chips is limited by the poor quality of prints achievable with widely available 3D printers. To mitigate this issue and facilitate rapid microfluidic device prototyping, we have developed a simple procedure to print microfluidic molds using a stereolithographic (SLA) printer and produce functional polydimethylsiloxane (PDMS) microfluidic chips with height and width feature dimensions as low as 75 {micro}m. Molds printed using a commercially available liquid photopolymer-based resin and processed using our strategy exhibited high dimensional fidelity to intended designs and significantly reduced average surface roughness (< 3 {micro}m). Here, we describe a streamlined post-print processing workflow for SLA molds and its efficacy in reducing surface roughness while preserving dimensional fidelity and then demonstrate its utility by prototyping and optimizing a microfluidic extracellular vesicle (EV)-exchange platform. Graphical AbstractRapid prototyping of microfluidic device features using stereolithographic 3D printing. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=110 SRC="FIGDIR/small/662041v1_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@126ff02org.highwire.dtl.DTLVardef@1301c7forg.highwire.dtl.DTLVardef@19edb96org.highwire.dtl.DTLVardef@6256b5_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2025

DNA six-way junction conformations and their use in a 2D square lattice

In this paper, we investigate the conformational landscape of the DNA six-way junction (6WJ), a higher-order extension of the DNA four-way junction (4WJ), to de-termine preferred structural isomers. The 6WJ allows for unique junction-level topolo-gies, and could be used to create novel DNA nanostructures, but the conformational landscape for the 6WJ is much more complex than the 4WJ. Our proposed confor-mational landscape for the 6WJ includes eight unique structural motifs, including an unstacked motif, five distinct stacked motifs, and two twisted motifs, and we estimate that there are forty structural isomers for the 6WJ, compared to only three for the 4WJ. To gain insight into these conformations, we perform all-atom molecular dynam-ics (MD) simulations on fourteen of the structural isomers. Our analysis shows that each 6WJ motif can be distinguished by its duplex stacking angles, and only a few of the 6WJ isomers have favorable free energies, which include the planar parallel isomers, the twisted isomers, and one of the orthogonal isomers. Lastly, to confirm that these stacked 6WJ motifs could be used to create larger-scale DNA nanostructures, we design a 2D square lattice using four orthogonal motifs connected in a 2x2 arrangement. Experimental characterization of this 2D lattice shows folding into the correct size and shape, further confirmed by AFM images of the DNA tiles, and an MD simulation that shows a slight twist of the lattice structure from orthogonality. This is the first 2D tile assembly built using an orthogonal junction-level topology for DNA nanotechnology, allowing a smaller mesh size than is possible with the 4WJ architecture.

bioengineering↗

bioRxiv2025

Designer DX-tile DNAns hydrogels

Pure deoxyribonucleic acid (DNA) hydrogels synthesized via the hybridization of multi-arm DNA tiles are uniquely programmable and functionalizable biomaterials suitable for applications ranging from biosensing to cell-free protein production and soft tissue engineering. However, the full potential of the design flexibility and functionalization offered by DNA molecules has not yet been leveraged for pure DNA hydrogels, thereby limiting their range of mechanical properties and reducing their versatility and broader use. In this study, we introduce multi-arm double-crossover (DX)-tile motifs, often used in DNA nanoparticle design, to enable greater control over the hydrogels mechanical properties and facilitate functionalization. Specifically, we demonstrate that modifying structural design parameters, such as the arm geometry, length, valency, and linker design, allows fine control of the elastic modulus and viscoelastic properties of the hydrogels. We also show that functionalization can be performed without compromising the hydrogels physical properties and exhibit enhanced mechanical strength and tunable properties, compared to simple duplex-based DNA hydrogels. Furthermore, these DNA hydrogels demonstrated printability and scalability, which pave the way towards the development of novel formulations and bioinks for the rational design of soft tissue engineering scaffolds and broaden the use of DNA hydrogels for other biomedical applications.

bioengineering↗