An Osmosis-driven 3D-printed brain implant for drug delivery.

Glioblastoma is a highly malignant brain tumor with limited survival rates due to challenges in complete surgical excision, high recurrence (> 90%), and the inefficacy of systemic drug delivery. Significant efforts have been made to develop drug-loaded brain implants, catheters, and wafers aimed at enhancing survival rates by suppressing tumor recurrence. However, these devices often fail due to clogging, reflux, and the inability to be fully implanted intracranially.

Reduced cell-substrate adhesion formation promotes cell migration in .

Many cells adhere to the extracellular matrix (ECM) for efficient cell migration. This adhesion is mediated by focal adhesions, a protein complex linking the ECM to the intracellular cytoskeleton. Focal adhesions have been studied extensively in metazoan mesenchymal cells, but recent research in physiological contexts and amoeboid cells suggests that focal adhesion regulation differs from the mesenchymal focal adhesion paradigm.

Waterborne protozoan parasite detection using two-frequency impedance flow cytometry.

Waterborne parasitic protozoa are common causes of gastrointestinal diseases in both humans and farm animals, even with standardized water treatment in place. This creates a need for continuous water monitoring to detect the presence of these micron-sized parasites in water sources to prevent potential outbreaks. This paper proposes a monitoring system consisting of a microfluidic channel embedded with micromachined microelectrodes to detect and evaluate protozoa at the individual (oo)cyst level in flowing water.

A spiral channel with integrated microelectrodes for label-free particle lateral position and size characterization.

Modified-trident shaped microelectrodes were incorporated into a spiral-shaped microfluidic focusing channel, utilizing impedance flow cytometry to analyze and quantify inertial microfluidic-based separation of homogeneous particles differing in size. Double peak voltage pulses were generated as particles moved across the electrodes, where the ratio of the peak amplitudes indicated the lateral particle positions inside the channel at various flow rates, while the peak amplitude indicated particle size and vertical position. The root mean square error between the optical and electrical position measurements was 11.

Achieving biocompatibility and tailoring mechanical properties of SLA 3D printed devices for microfluidic and cell culture applications.

Stereolithography (SLA) and other photopolymerization-based additive manufacturing approaches are becoming popular for the fabrication of microfluidic devices and cell-infused platforms, but many of the resins employed in these techniques are cytotoxic to cells or do not have the appropriate mechanical properties for microfluidic components. Here, using a commercially available resin, we demonstrate that biocompatibility and a range of mechanical properties can be achieved through post-print optimization involving baking, soaking, network swelling, and UV exposure. We show that UV-vis spectrophotometry can be used to detect methacrylate monomer/oligomer, and utilizing this method, we found that baking at 120 °C for 24 hours was the optimal method for removing cytotoxic chemical species and creating nontoxic cell culture platforms, though UV exposure and soaking in 100% ethanol also can substantially reduce cytotoxicity.

Reduced cell-substrate adhesion formation promotes cell migration in .

Many cells adhere to the extracellular matrix for efficient cell migration. This adhesion is mediated by focal adhesions, a protein complex linking the extracellular matrix to the intracellular cytoskeleton. Focal adhesions have been studied extensively in Metazoan mesenchymal cells, but recent research in physiological contexts and amoeboid cells suggest that focal adhesion regulation differs from the mesenchymal focal adhesion paradigm.

Using Electroporation to Improve and Accelerate Zebrafish Embryo Toxicity Testing.

Zebrafish have emerged as a useful model for biomedical research and have been used in environmental toxicology studies. However, the presence of the chorion during the embryo stage limits cellular exposure to toxic elements and creates the possibility of a false-negative or reduced sensitivity in fish embryo toxicity testing (FET). This paper presents the use of electroporation as a technique to improve the delivery of toxic elements inside the chorion, increasing the exposure level of the toxins at an early embryo stage (<3 h post-fertilization).

Characterizing a Silver Nanoparticle-Based Electrochemical Biosensor for Shiga Toxin Detection.

Shiga toxins (1, 2) regularly cause outbreaks and food recalls and pose a significant health risk to the infected population. Therefore, new reliable tools are needed to rapidly detect Shiga toxin cost-effectively in food, water, and wastewater before human consumption. Enzyme immunoassay and polymerase chain reaction approaches are the gold standard detection methods for the Shiga toxin.

Transgenic expression in zebrafish embryos with an intact chorion by electroporation and microinjection.

Electroporation is regularly used to deliver agents into cells, including transgenic materials, but it is not used for mutating zebrafish embryos due to the lack of suitable systems, information on appropriate operating parameters, and the challenges posed by the protective chorion. Here, a novel method for gene delivery in zebrafish embryos was developed by combining microinjection into the space between the chorion and the embryo followed by electroporation. This method eliminates the need for chorion removal and injecting into the space between the chorion and embryo eliminates the need for finding and identifying key cell locations before performing an injection, making the process much simpler and more automatable.

Utilizing ChatGPT to assist CAD design for microfluidic devices.

ChatGPT is a generative AI model that has garnered tremendous public interest due to its ability to solve diverse problems through high-level reasoning and analysis. Among its features is an ability to create and debug code. While this capability has been explored with conventional programming languages such as Python, it has yet to be applied to computer-aided design (CAD).

Insight into the formation and biological effects of natural organic matter corona on silver nanoparticles in water environment using biased cyclical electrical field-flow fractionation.

Natural organic matter (NOM) readily interacts with nanoparticles, leading to the formation of NOM corona structures on their surface. NOM corona formation is closely related to the surface coatings and bioavailability of nanoparticles. However, the mechanism underlying NOM corona formation on silver nanoparticles (AgNPs) remains largely unknown due to the lack of effective analytical methods for identifying the changes in the AgNP surface.

Multiple-Streams Focusing-Based Cell Separation in High Viscoelasticity Flow.

Viscoelastic flow has been widely used in microfluidic particle separation processes, in which particles get focused on the channel center in diluted viscoelastic flow. In this paper, the transition from single-stream focusing to multiple-streams focusing (MSF) in high viscoelastic flow is observed, which is applied for cell separation processes. Particle focusing stream bifurcation is caused by the balance between elastic force and viscoelastic secondary flow drag force.

Separation of U87 glioblastoma cell-derived small and medium extracellular vesicles using elasto-inertial flow focusing (a spiral channel).

Nanoscale and microscale cell-derived extracellular vesicle types and subtypes are of significant interest to researchers in biology and medicine. Extracellular vesicles (EVs) have diagnostic and therapeutic potential in terms of biomarker and nanomedicine applications. To enable such applications, EVs must be isolated from biological fluids or separated from other EV types.

Viscoelastic Particle Focusing and Separation in a Spiral Channel.

As one type of non-Newtonian fluid, viscoelastic fluids exhibit unique properties that contribute to particle lateral migration in confined microfluidic channels, leading to opportunities for particle manipulation and separation. In this paper, particle focusing in viscoelastic flow is studied in a wide range of polyethylene glycol (PEO) concentrations in aqueous solutions. Polystyrene beads with diameters from 3 to 20 μm are tested, and the variation of particle focusing position is explained by the coeffects of inertial flow, viscoelastic flow, and Dean flow.

Compression of the vascular wall to create a friction fit in a vascular anastomotic coupler.

A previously reported microvascular coupler was shown to effectively create vascular anastomoses, but was too large for practical clinical use. To safely reduce coupler size, certain failure modes needed to be better understood. The coupler functions, in part, by compressing the vessel wall between two concentric rings, creating a friction fit that anchors the device to the vessel.

High efficiency rare sperm separation from biopsy samples in an inertial focusing device.

Immotile and rare sperm isolation from a complex cell background is an essential process for infertility treatment. The traditional sperm collection process from a biopsy sample requires long, tedious searches, yet still results in low sperm retrieval. In this work, a high recovery, high throughput sperm separation process is proposed for the clinical biopsy sperm retrieval process.

Development and Testing of a Continuous Flow-Electrical-Split-Flow Lateral Transport Thin Separation System (Fl-El-SPLITT).

In this work, a new high-volume, continuous particle separation device that separates based upon size and charge is described. Two continuous flow-electrical-split-flow lateral transport thin (Fl-El-SPLITT) device architectures (a platinum electrode on a porous membrane and a porous graphite electrode under a membrane) were developed and shown to improve particle separations over a purely electrical-SPLITT device. The graphite FL-El-SPLITT device architecture achieved the best separation of approximately 60% of small (28 nm) vs large (1000 nm) polystyrene particles.

Optimization of a microfluidic spiral channel used to separate sperm from blood cells.

Assisted reproductive technology includes medical procedures that confront the problem of infertility. In some cases of male infertility, blood cells are present in the sperm containing samples and must be removed. Spiral-channel devices have been developed to perform this task, but there is a strong need to increase their throughput.

SARS-CoV-2 pandemic: a review of molecular diagnostic tools including sample collection and commercial response with associated advantages and limitations.

The unprecedented global pandemic known as SARS-CoV-2 has exercised to its limits nearly all aspects of modern viral diagnostics. In doing so, it has illuminated both the advantages and limitations of current technologies. Tremendous effort has been put forth to expand our capacity to diagnose this deadly virus.

Characterization of Human Glioblastoma versus Normal Plasma-Derived Extracellular Vesicles Preisolated by Differential Centrifugation Using Cyclical Electrical Field-Flow Fractionation.

Although many properties for small extracellular vesicles (sEVs, formerly termed "exosomes") isolated at ∼100 000 are known, a wide range of values are reported for their electrophoretic mobility (EM) measurements. This paper reports for the first time the effect of dilution on the EM of U87 glioblastoma cell-derived and plasma-derived sEVs and medium size EVs (mEVs, commonly termed "oncosomes") preisolated by differential centrifugation. Furthermore, the effect of resalting on the EM of sEVs and mEVs was evaluated.

Towards a better testicular sperm extraction: novel sperm sorting technologies for non-motile sperm extracted by microdissection TESE.

Non-obstructive azoospermia (NOA) is the most severe form of male factor infertility. It is characterized by a lack of spermatogenesis in the seminiferous tubules. Microdissection testicular sperm extraction (microTESE) has significantly improved testicular sperm retrieval rates compared to conventional techniques for NOA.

Viscoelastic second normal stress difference dominated multiple-stream particle focusing in microfluidic channels.

Particle focusing in viscoelastic fluid flow is a promising approach for inducing particle separations in microfluidic devices. The results from theoretical studies indicated that multiple stream particle focusing can be realized with a large magnitude of the elastic second normal stress difference (N). For dilute polymer solutions, theoretical and experimental studies show that the magnitude of N is never large, no matter how large the polymer molecular weight nor how high the shear rate.

Microfluidic System for Rapid Isolation of Sperm From Microdissection TESE Specimens.

Objectives: To demonstrate a novel prototype microfluidic system for rapid isolation of sperm from real and simulated microdissection testicular sperm extraction samples.

Methods: The novel microfluidic system was tested using minced testicular biopsies from patients with nonobstructive azoospermia. The samples were split into 2 portions, conventional processing vs microfluidic.