Biology subjects

Hu, C.-H.

Publications and source records attributed to Hu, C.-H..

4 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

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↗

bioRxiv2024

Designer DNA Strand Displacement Reaction toward Controlled Release of Cargos

Dynamic DNA nanotechnology systems are used to design DNA logic circuits, signal amplification mechanisms for biosensing, and smart release system that could potentially be used in several biomedical applications. The toehold-mediated strand displacement reaction (TMSDR) is one of the main methods for designing DNA-based biomolecular logic circuits. However, the reaction behaviour such as the displacement rate and the quantity of strand released are difficult to control and often requires chemically modified strands or addition of enzymes. This makes the TMSDR versatility and specificity limited, and not always adapted for biomedical applications. Therefore, further understanding the sequence design parameters enabling fine tuning of the TMSDR behaviour without the need for complex modification, would enable its broader application. In this study, using a DNA motif developed for multiplexed release, we examine how mismatched base(s) in the trigger strand is affecting the release rate and quantity released and found that both location and type of mismatched base(s) significantly impact the displacement parameters of the TMSDR. This allows for a finer control of the cargo release for the multiplexed release system that could be used for varying biomedical applications and help developing release system mimicking the natural distribution of biomolecules.

bioengineering↗

bioRxiv2022

Size-tunable ICG-based contrast agent platform for targeted near-infrared photoacoustic imaging

Near-infrared photoacoustic imaging (NIR-PAI) combines the advantages of optical and ultrasound imaging to provide anatomical and functional information of tissues with high resolution. Although NIR-PAI is promising, its wide application is hindered by the limited availability of NIR contrast agents. J-aggregates (JA) made of indocyanine green dye (ICG) represents an attractive class of biocompatible contrast agents for PAI. Here, we present a facile synthesis method that combines ICG and ICG-azide dyes for producing contrast agent with tunable size down to 230 nm and direct functionalization with targeting moieties. The ICG-JA platform has a detectable PA signal in vitro that is two times stronger than whole blood and high photostability. The targeting ability of ICG-JA was measured in vitro using HeLa cells. The ICG-JA platform was then injected into mice and in vivo NIR-PAI showed enhanced visualization of liver and spleen for 90 minutes post-injection with a contrast-to-noise ratio of 2.42.

bioengineering↗