Cost-Effective and Simple Prototyping PMMA Microfluidic Chip and Open-Source Peristaltic Pump for Small Volume Applications

Microfluidics. Big things in narrow channels.

Two hundred eight tissue specimens from 81 patients were examined by centrifugation culture for the rapid diagnosis of invasive cytomegalovirus (CMV) infection. Results were compared with those obtained by both conventional viral cultures and histologic examination. CMV was identified by centrifugation culture in 52 (25%) specimens at 16 hours after inoculation, including 39 lung specimens and 12 gastrointestinal specimens. One additional esophageal specimen was positive (53 of 208 specimens; 25.5%) at 36 hours. In contrast, CMV was recovered from only 50 of these 53 specimens by conventional cell culture at a mean of 11 days after inoculation. Forty-three of the 208 specimens (20.5%) were positive for CMV when examined by histologic methods, including light microscopy and tissue immunofluorescence. All 43 were positive by centrifugation culture. Specimens that were positive by centrifugation culture but negative by histologic methods included three lung specimens and seven gastrointestinal specimens. The technic of centrifugation culture is more sensitive for diagnosis of invasive CMV infection by the examination of affected tissue than either conventional viral culture or histologic technics, including tissue immunofluorescence, and more rapid than conventional culture or routine histologic examination.

Malignant pleural effusion is a common clinical problem, which often occurs in cases of malignant tumors, especially in lung cancer. In this paper, a pleural effusion detection system based on a microfluidic chip, combined with specific tumor biomarker, hexaminolevulinate (HAL), used to concentrate and identify tumor cells in pleural effusion was reported. The lung adenocarcinoma cell line A549 and mesothelial cell line Met-5A were cultured as the tumor cells and non-tumor cells, respectively. The optimum enrichment effect was achieved in the microfluidic chip when the flow rates of cell suspension and phosphate-buffered saline achieved 2 mL/h and 4 mL/h, respectively. At the optimal flow rate, the proportion of A549 increased from 28.04% to 70.01% due to the concentration effect of the chip, indicating that tumor cells could be enriched by a factor of 2.5 times. In addition, HAL staining results revealed that HAL can be used to identify tumor cells and non-tumor cells in chip and clinical samples. Additionally, the tumor cells obtained from the patients diagnosed with lung cancer were confirmed to be captured in the microfluidic chip, proving the validity of the microfluidic detection system. This study preliminarily demonstrates the microfluidic system is a promising method with which to assist clinical detection in pleural effusion.

State-of-the-art microfluidic systems rely on relatively expensive and bulky off-chip infrastructures. The core of a system—the microfluidic chip—requires a clean room and dedicated skills to be fabricated. Thus, state-of-the-art microfluidic systems are barely accessible, especially for the do-it-yourself (DIY) community or enthusiasts. Recent emerging technology—3D-printing—has shown promise to fabricate microfluidic chips more simply, but the resulting chip is mainly hardened and single-layered and can hardly replace the state-of-the-art Polydimethylsiloxane (PDMS) chip. There exists no convenient fluidic control mechanism yet suitable for the hardened single-layered chip, and particularly, the hardened single-layered chip cannot replicate the pneumatic valve—an essential actuator for automatically controlled microfluidics. Instead, 3D-printable non-pneumatic or manually actuated valve designs are reported, but their application is limited. Here, we present a low-cost accessible all-in-one portable microfluidic system, which uses an easy-to-print single-layered 3D-printed microfluidic chip along with a novel active control mechanism for fluids to enable more applications. This active control mechanism is based on air or gas interception and can, e.g., block, direct, and transport fluid. As a demonstration, we show the system can automatically control the fluid in microfluidic chips, which we designed and printed with a consumer-grade 3D-printer. The system is comparably compact and can automatically perform user-programmed experiments. All operations can be done directly on the system with no additional host device required. This work could support the spread of low budget accessible microfluidic systems as portable, usable on-the-go devices and increase the application field of 3D-printed microfluidic devices.

Nuclear events such as chromatin condensation, DNA cleavage at internucleosomal sites, and histone release from chromatin are recognized as hallmarks of apoptosis. However, there is no complete understanding of the molecular events underlying these changes. It is likely that epigenetic changes such as DNA methylation and histone modifications that are involved in chromatin dynamics and structure are also involved in the nuclear events described. In this report we have shown that apoptosis is associated with global DNA hypomethylation and histone deacetylation events in leukemia cells. Most importantly, we have observed a particular epigenetic signature for early apoptosis defined by a release of hypoacetylated and trimethylated histone H4 and internucleosomal fragmented DNA that is hypermethylated and originates from perinuclear heterochromatin. These findings provide one of the first links between apoptotic nuclear events and epigenetic markers.

Nuclear reactor process control is typically monitored for pure β-emitting radionuclides via manual sampling followed by laboratory analysis, leading to delays in data availability and response times. The development of an in situ microfluidic Lab on Chip (LoC) system with integrated detection capable of measuring pure β-emitting radionuclides presents a promising solution, enabling a reduction in occupational exposure and cost of monitoring whilst providing improved temporal resolution through near real-time data acquisition. However, testing prototypes with radioactive sources is time-consuming, requires specialist facilities/equipment, generates contaminated waste, and cannot rapidly evaluate a wide range of designs or configurations. Despite this, modelling multiple design parameters and testing their impact on detection with non-radioactive substitutes has yet to be adopted as best practice. The measurement of pure β emitters in aqueous media relies on the efficient transport of photons generated by the Cherenkov effect or liquid scintillators to the detector. Here we explore the role of numerical modelling to assess the impact of optical cell geometry and design on photon transmission and detection through the microfluidic system, facilitating improved designs to realise better efficiency of integrated detectors and overall platform design. Our results demonstrate that theoretical modelling and an experimental evaluation using non-radiogenic chemiluminescence are viable for system testing design parameters and their impact on photon transport. These approaches enable reduced material consumption and requirement for specialist facilities for handling radioactive materials during the prototyping process. This method establishes proof of concept and the first step towards numerical modelling approaches for the design optimisation of microfluidic LoC systems with integrated detectors for the measurement of pure β emitting radionuclides via scintillation-based detection.

Long-term three-dimensional cell culture and anticancer drug activity evaluation in a microfluidic chip

Expansion of cord blood stem cells in fibronectin-coated microfluidic bioreactor

This program is to improve the traditional germ cell culture technology, and expected to develop and validate the innovative germ cell microfluidic culture technology. The main concept is to use the in vitro microfluidic chip to mimic the fluid growth environment in the living body, and to shape the growth environment of the zygote cells into a bionic concept in the uterus. The main objective is to design to the most suitable growth conditions, the importance of which is to increase the chance of zygote cell culture to maturity and greatly improve the maturity of zygotic cells. Assist Reproductive technology is a related technology for in vitro washing, culturing and storage of human germ cells. The main method is to use an artificial culture medium that mimics the human body fluid of the human reproductive system to perform in vitro washing, culture, and storage of reproductive gametophytic cells. The project will be divided into three parts: 1. Bionic microfluidic chip design and production; 2. Biocompatibility and materialization analysis; 3. Germ cell chip efficacy verification. Therefore, this project will develop a continuous microfluidic chip, using a continuous microfluidic channel to simulate the growth of human germ cells in the fertility tube to the zygotic germ cell growth environment, and hope to improve the artificial reproductive technology success rate and pregnancy rate. Reduce the cost of repeated artificial reproduction, and eventually, develop into medical-grade products and promote local technology to the international market.

This paper first prepared and characterized an all solid zinc ion selective electrode using electrode deposition, and further established a microfluidic chip system integrating zinc ion ASS-ISE and a self-made potential detection device. The stability of the self-made potential detection device was verified by comparing it with traditional electrochemical workstations. The accuracy of the microfluidic chip detection system was verified through comparative testing with traditional atomic absorption spectrophotometry (AAS). The experimental results show that the accuracy and stability of the microfluidic chip system integrated with ASS-ISE and self-made potential detection device meet the requirements of on-site rapid detection.

Microelectromechanical systems (MEMS) technology has matured to the point where practical biological and chemical applications are possible. One particularly active research area is in the development of lab-on-a-chip type systems. In order to create successful lab-on-a-chip and other microfluidic systems, it is necessary to have the capability of controlling and directing fluid flow. Such functionality can be found on the front end of a microfluidic system and is known as a fluid delivery or dosing subsystem. For a MEMS micro fluid dosing system to be realized, several components are necessary. The essential components include a fluid actuator, a fluidic control device, and micro plumbing. A prototype fluid delivery system is demonstrated here using a micropump as the fluid actuator, a thermal flow sensor as the fluidic control device, and micromachined couplers as plumbing. The technology to build these components has been developed and each of these components have been fabricated and tested. A prototype constructed of discrete components has also been demonstrated. A truly integrated, channel-based fluid dosing system can be achieved through device scaling.

Material and fabrication at low-cost used for lab-on-a-chip (LOC) system and the ease of operation without expensive and complicated instruments are crucial for wide application in our daily life. The current low-cost LOC material could be categorized as two types: paper-based LOC and polymer like polydimethylsiloxane (PDMS) based device. Paper-based devices enable the advantages of easy fabrication, disposable nature and least cost. Using an office laser printer to create a carbon powder pattern on the filter paper, we created a microwell pattern area of which the uncovered carbon powder enables a flow rate greater than that where covered with carbon powder along the filter; the flow can carry and localize single microalgae into the microwell separately. The separation process only takes 30 seconds and the separation performance of isolating single microalgae could be over 37% in average. The open-structure design of the paper device makes it operable with a common laboratory micropipette for sample retrieval and transfer. The paper-device can also function as an incubator for microalgae growth on simply rinsing the paper with a growth medium. In this research, we developed PDMS based filter LOC devices to separate microalgae and detect circulating tumor cells (CTCs). Clogging always becomes a main issue on filter based separation; cross-flow system was proven to reduce this drawback. We develop a centrifugally driven, multilayer, concentric filter device, a small bench-top centrifuge, which is commonly available in biochemical laboratories, was employed as part of our centrifugal microfluidic separation system. The cross-flow in our separation system was simply generated on altering the rate of rotation, as revolutions per minute (RPM), instantly through the relative motion of the device and the fluid. This strong cross-flow can wash away the particle and microalgae clogs at the filter pores, so increasing the filtration performance over 13.7 % without complicated control and expensive equipment. The use of the PDMS filter device enabled variously sized microparticles and environmentally collected microalgae samples to be readily separated in a few minutes. This device was also applied to detect CTCs. By using the anti–human EpCAM antibody coated polystyrene (PS) beads to capture CTCs which could enlarge the size of CTCs to create significant size different from normal cell like white blood cells (WBCs). With a concentric filter device and centrifugation, the unbound PS beads and WCBs would flow to the outer layer of the device; the targeted CTCs bound with PS beads would be retained in the inner filter layer. The inner filter layer is designed as a detection zone in which the bound cells are easily observed by microscope because of the small area of the inner channel and the enrichment effect. We successfully demonstrate that CTCs could be separated and detected in the concentration of one CTC per million of WBCs by this device and method.

Organoid-on-chip systems represent a transformative advancement in preclinical research, offering an innovative platform that integrates the biological complexity of organoids with the precise microengineering of organ-on-chip technologies. These hybrid systems recreate physiologically relevant tissue microenvironments, enabling dynamic control of biochemical, mechanical, and fluidic conditions that closely mimic in vivo physiology. By incorporating patient-derived organoids onto microfluidic chips, organoid-on-chip platforms provide unprecedented opportunities for personalized drug screening, enabling the evaluation of drug efficacy, toxicity, and pharmacokinetics in models that retain individual-specific genetic and phenotypic characteristics. This approach enhances predictive accuracy compared with conventional 2D cell cultures and animal models, thereby reducing translational gaps in drug development. In disease modeling, organoid-on-chip technology allows for the simulation of complex human disease states, such as cancer progression, metabolic disorders, neurodegenerative diseases, and infectious diseases. The microfluidic environment supports long-term culture, real-time monitoring, and multi-organ interactions, facilitating deeper insights into disease mechanisms. Additionally, integration with sensors and imaging modalities enables high-resolution analysis of cellular responses and molecular pathways.Overall, organoid-on-chip systems offer a powerful, scalable, and physiologically relevant platform for drug discovery, toxicity assessment, and mechanistic disease studies. Their ability to simulate patient-specific responses positions them as a promising tool for precision medicine, accelerating the development of safer and more effective therapeutics.

ABSTRACTOne of the greatest bottlenecks in extracellular vesicle (EV) research is the production of sufficient material in a consistent and effective way using in vitro cell models. Although the production of EVs in bioreactors maximizes EV yield in comparison to conventional cell cultures, the impact of their cell growth conditions on EVs has not yet been established. In this study, we grew two prostate cancer cell lines, PC-3 and VCaP, in conventional cell culture dishes and in two-chamber bioreactors to elucidate how the growth environment affects the EV characteristics. Specifically, we wanted to investigate the growth condition-dependent differences by non-targeted metabolite profiling using liquid chromatography–mass spectrometry (LC–MS) analysis. EVs were also characterized by their morphology, size distribution, and EV protein marker expression, and the EV yields were quantified by NTA. The use of bioreactor increased the EV yield >100 times compared to the conventional cell culture system. Regarding morphology, size distribution and surface markers, only minor differences were observed between the bioreactor-derived EVs (BR-EVs) and the EVs obtained from cells grown in conventional cell cultures (C-EVs). In contrast, metabolomic analysis revealed statistically significant differences in both polar and non-polar metabolites when the BR-EVs were compared to the C-EVs. The results show that the growth conditions markedly affected the EV metabolite profiles and that metabolomics was a sensitive tool to study molecular differences of EVs. We conclude that the cell culture conditions of EV production should be standardized and carefully detailed in publications and care should be taken when EVs from different production platforms are compared with each other for systemic effects.

In vivo, the complex process of drugs metabolism alters the change in drug composition and determines the final pharmacological properties of oral drugs. Ginsenosides are primary constituents of ginseng, whose pharmacological activities are greatly affected by liver metabolism. However, the predictive power of existing in vitro models is poor due to their inability to mimic the complexity of drug metabolism in vivo. The advance of organs-on-chip-based microfluidics system could provide a new in vitro drug screening platform by recapitulating the metabolic process and pharmacological activity of natural product. In this study, an improved microfluidic device was employed to establish an in vitro co-culture model by culturing multiple cell types in compartmentalized microchambers. Different cell lines were seeded on the device to examine the metabolites of ginsenosides from the hepatocytes in top layer and its resulting efficacy on the tumors in bottom layer. Metabolism dependent drug efficacy of Capecitabine in this system demonstrated the model is validated and controllable. High concentrations of CK, Rh2 (S), and Rg3 (S) ginsenosides showed significant inhibitory effects on two types of tumor cells. In addition, apoptosis detection showed that Rg3 (S) through liver metabolism promoted early apoptosis of tumor cells and displayed better anticancer activity than prodrug. The detected ginsenoside metabolites indicated that some protopanaxadiol saponins were converted into other anticancer aglycones in varying degrees due to orderly de-sugar and oxidation. Ginsenosides exhibited different efficacy on target cells by impacting their viabilities, indicating hepatic metabolism plays an important role in determining ginsenosides efficacy. In conclusion, this microfluidic co-culture system is simple, scalable, and possibly widely applicable in evaluating anticancer activity and metabolism of drug during the early developmental phases of natural product.