Biomicrofluidics最新文献

Bio-microfluidic technologies offer promising applications in diagnostics and therapy, yet they face significant technical challenges, particularly in the need for external power sources, which limits their practicality and user-friendliness. Recent advancements have explored innovative methods utilizing body fluids, motion, and heat to power these devices, addressing the power supply issue effectively. Among these, body-motion and body-heat-powered systems stand out for their potential to create self-sustaining, wearable, and implantable devices. In this Perspective, we focus on the principles and applications of hydrovoltaic cells, biofuel cells, and piezoelectric and triboelectric nanogenerators. Recent strides in energy conversion efficiency, coupled with the development of biocompatible and durable materials, are driving innovation in bio-integrated electronics. Integration with bio-microfluidic platforms further enhances the linkage to the human body and the potential of these devices for personalized healthcare applications. Ongoing research into these areas promises to deliver sustainable and user-friendly solutions for continuous monitoring, diagnostics, and therapy, potentially revolutionizing the landscape of healthcare delivery.

Chimeric antigen receptor (CAR) T-cell therapy shows unprecedented efficacy for cancer treatment, particularly in treating patients with various blood cancers, most notably B-cell acute lymphoblastic leukemia. In recent years, CAR T-cell therapies have been investigated for treating other hematologic malignancies and solid tumors. Despite the remarkable success of CAR T-cell therapy, cytokine release syndrome (CRS) is an unexpected side effect that is potentially life-threatening. Our aim is to reduce pro-inflammatory cytokine release associated with CRS by controlling CAR surface density on CAR T cells. We show that CAR expression density can be titrated on the surface of primary T cells using an acoustic-electric microfluidic platform. The platform performs dosage-controlled delivery by uniformly mixing and shearing cells, delivering approximately the same amount of CAR gene coding mRNA into each T cell.

Platelet transfusion is a lifesaving therapy intended to prevent and treat bleeding. However, in addition to platelets, a typical unit also contains a large volume of supernatant that accumulates multiple pro-inflammatory contaminants, including residual leukocytes, microaggregates, microparticles, antibodies, and cytokines. Infusion of this supernatant is responsible for virtually all adverse reactions to platelet transfusions. Conventional methods for removing residual leukocytes (leukoreduction) and reducing the volume of transfused supernatant (volume reduction) struggle to mitigate these risks holistically. Leukoreduction filters can remove leukocytes and microaggregates but fail to reduce supernatant volume, whereas centrifugation can reduce volume, but it is ineffective against larger contaminants and damages platelets. Additionally, platelet purification based on these methods is often too logistically complex, time-consuming, and labor-intensive to implement routinely. Emerging microfluidic technologies offer promising alternatives through passive separation mechanisms that enable cell separation with minimal damage and drastically reduced instrumentation size and facility requirements. This review examines recent innovations in microfluidic cell separation that can be used for leukoreduction and volume reduction of platelets. It begins by defining the performance requirements that any separation method must meet to successfully replace conventional methods currently used to perform these tasks. Standard performance metrics are described, including leukocyte depletion efficiency, degree of volume reduction, processing throughput, and platelet recovery. Finally, the review outlines the primary challenges that must be overcome to enable simple-to-use, disposable microfluidic devices capable of both reducing the platelet unit volume and removing pro-inflammatory contaminants, while preserving most functional platelets for transfusion.

Drug delivery technologies, which are a crucial area of research in the field of cell biology, aim to actively or passively deliver drugs to target cells to enhance therapeutic efficacy and minimize off-target effects. In recent years, with advances in drug development, particularly, the increasing demand for macromolecular drugs (e.g., proteins and nucleic acids), novel drug delivery technologies and intracellular cargo delivery systems have emerged as promising tools for cell and gene therapy. These systems include various viral- and chemical-mediated methods as well as physical delivery strategies. Physical methods, such as electroporation and microinjection, have shown promise in early studies but have not been widely adopted due to concerns regarding efficiency and cellular viability. Recently, microfluidic technologies have provided new opportunities for cargo delivery by allowing for precise control of fluid dynamic parameters to achieve efficient and safe penetration of cell membranes, as well as for foreign material transport. Microfluidics-based mechanical delivery methods utilize biophysical phenomena, such as cell constriction and fluid shear, and are associated with high throughput and high transfection efficiency. In this review, we summarize the latest advancements in microfluidic mechanical delivery technologies, and we discuss constriction- and fluid shear-induced delivery strategies. Furthermore, we explore the potential application of artificial intelligence in optimizing cargo delivery technologies, aiming to provide theoretical support and practical guidance for the future development of novel cellular drug delivery technologies.

Accurate detection of pathogenic nucleic acids is crucial for early diagnosis, effective treatment, and containment of infectious diseases. It facilitates the timely identification of pathogens, aids in monitoring disease outbreaks, and helps prevent the spread of infections within healthcare settings and communities. We developed a multi-layered, paper-based microfluidic and miniaturized electrophoresis system for rapid nucleic acid extraction, separation, amplification, and detection, designed for resource-limited settings. Constructed from acrylic, transparency film, pressure-sensitive adhesion, and Whatman paper using a CO₂ laser, the setup simplifies traditional methods and eliminates the need for complex equipment. DNA extraction and purification are achieved using Zweifach-Fung bifurcation and Fahraeus effect principles, with detection via a hydrogel-assisted colorimetric isothermal reverse transcriptase-loop-mediated isothermal amplification technique. The system accurately identified the SARS-CoV-2 N-gene and β-actin human gene, validated by a compact electrophoresis setup. In clinical validation with 12 patient specimens, the system demonstrated a positive predictive agreement of 83.0% and a negative predictive agreement of 100%. The system achieves a limit of detection of 1 copy/μl and can potentially transform nucleic acid detection assays in healthcare settings. This study addresses key challenges in nucleic acid detection, such as ensuring sample quality and quantity, reducing reliance on sophisticated equipment, preventing contamination, simplifying procedures, and providing rapid and accurate diagnostics for emerging pathogens.

Rheotaxis is one of the major migratory mechanisms used in autonomous swimmers such as sperms and bacteria. Here, we present a microfluidic chip using joint rheotaxis and boundary-following behavior that selects sperms based on the motility and persistence. The proposed device consists of a channel decorated with diamond-shaped pillars that create spots of increased velocity field and shear rate. These spots are supposed as hydrodynamic barriers that impede the passage of less motile sperms through the channels, while highly motile sperms were able to overcome the generated barrier and swim through the structures. The proposed device was able to populate the chamber with sorted sperms that were fully viable and motile. The experimental results validated the separation of highly motile sperms with enhanced motility parameters compared with the initial sample. Our device was able to improve linear straight velocity, curvilinear velocity, and average path velocity of the sorted population surpassing 35%, compared with the raw semen. The processing time was also reduced to 20 min.

Single-cell printing technology has arisen as a potent instrument for investigating cell biology and disease pathophysiology. Nonetheless, current single-cell printing methodologies are hindered by restricted throughput, a limited field of view, and diminished efficiency. We present an innovative single-cell printing chip that utilizes thermal inkjet technology for single-cell printing, therefore addressing these constraints. We have accomplished high-throughput, wide-field, and efficient single-cell printing by merging a high-density thermal foam-based inkjet nozzle array on a chip with high-speed cameras and computer vision technologies for optical image capture and single-cell identification training. We have shown the efficacy and adaptability of the printing chip by printing various concentrations of Chinese hamster ovary cells and human embryonic kidney 293 cells. The printing of a single 96-well plate is accomplished in 2-3 min, facilitating one-time loading and uninterrupted multi-plate paving. Our thermal bubble single-cell printing chip serves as a viable platform for high-throughput single-cell analysis applications.

Cardiovascular diseases are the leading cause of morbidity and mortality worldwide with numerous inflammatory cell etiologies associated with impaired cardiac function and heart failure. Inflammatory cardiomyopathy, also known as myocarditis, is an acquired cardiomyopathy characterized by inflammatory cell infiltration into the myocardium with a high risk of progression to deteriorated cardiac function. Recently, amidst the ongoing COVID-19 pandemic, the emergence of acute myocarditis as a complication of SARS-CoV-2 has garnered significant concern. Given its mechanisms remain elusive in conjunction with the recent withdrawal of previously FDA-approved antiviral therapeutics and prophylactics due to unexpected cardiotoxicity, there is a pressing need for human-mimetic platforms to investigate disease pathogenesis, model dysfunctional features, and support pre-clinical drug screening. Traditional in vitro models for studying cardiovascular diseases have inherent limitations in recapitulating the complexity of the in vivo microenvironment. Heart-on-a-chip technologies, combining microfabrication, microfluidics, and tissue engineering techniques, have emerged as a promising approach for modeling inflammatory cardiac diseases like myocarditis. This review outlines the established and emerging conditions of inflamed myocardium, identifying key features essential for recapitulating inflamed myocardial structure and functions in heart-on-a-chip models, highlighting recent advancements, including the integration of anisotropic contractile geometry, cardiomyocyte maturity, electromechanical functions, vascularization, circulating immunity, and patient/sex specificity. Finally, we discuss the limitations and future perspectives necessary for the clinical translation of these advanced technologies.

The development of a non-invasive method for measuring the internal fluid behavior and dynamics of microchannels in microfluidics poses critical challenges to biological research, such as understanding the impact of wall shear stress (WSS) in the growth of a bone-forming osteoblast. This study used the General Defocus Particle Tracking (GDPT) technique to develop a non-invasive method for quantifying the fluid velocity profile and calculated the WSS within a microfluidic chip. The GDPT estimates particle motion in a three-dimensional space by analyzing two-dimensional images and video captured using a single camera. However, without a lens to introduce aberration, GDPT is prone to error in estimating the displacement direction for out-of-focus particles, and without knowing the exact refractive indices, the scaling from estimated values to physical units is inaccurate. The proposed approach addresses both challenges by using theoretical knowledge on laminar flow and integrating results obtained from multiple analyses. The proposed approach was validated using computational fluid dynamics (CFD) simulations and experimental video of a microfluidic chip that can generate different WSS levels under steady-state flow conditions. By comparing the CFD and GDPT velocity profiles, it was found that the Mean Pearson Correlation Coefficient is 0.77 (max = 0.90) and the Mean Intraclass Correlation Coefficient is 0.66 (max = 0.82). The densitometry analysis of osteoblast cells cultured on the designed microfluidic chip for four days revealed that the cell proliferation rate correlates positively with the measured WSS values. The proposed analysis can be applied to quantify the laminar flow in microfluidic chip experiments without specialized equipment.

Rapid prototyping and fabrication of microstructure have been revolutionized by 3D printing, especially stereolithography (SLA) based techniques due to the superior spatial resolution they offer. However, SLA-type 3D printing faces intrinsic challenges in multi-material integration and adaptive Z-layer slicing due to the use of a vat and a mechanically controlled Z-layer generation. In this paper, we present the conceptualization of a novel paradigm which uses dynamic and multi-phase laminar flow in a microfluidic channel to achieve fabrication of 3D objects. Our strategy, termed "in situ 3D polymerization," combines in situ polymerization and co-flow aqueous two-phase systems and achieves slicing, polymerization, and layer-by-layer printing of 3D structures in a microchannel. The printing layer could be predicted and controlled solely by programming the fluid input. Our strategy provides generalizability to fit with different light sources, pattern generators, and photopolymers. The integration of the microfluidic channel could enable high-degree multi-material integration without complicated modification of the 3D printer.