Hydrogels as artificial matrices for cell seeding in microfluidic devices

The microfluidic 3D cell culture system has been an attractive model because it mimics the tissue and disease model, thereby expanding our ability to control the local cellular microenvironment. However, these systems still have limited value as quantitative assay tools due to the difficulties associated with the manipulation and maintenance of microfluidic cells, and their lack of compatibility with the high-throughput screening (HTS) analysis system. In this study, we suggest a microchannel-free, 3D cell culture system that has a hydrogel-incorporating unit integrated with a multi-well plate (24- to 96-well plate), which can provide better reproducibility in biological experiments. This plate was devised considering the design constraints imposed by various cell biology applications as well as by high-throughput analysis where the physical dimensions of the micro-features in the hydrogel-incorporating units were altered. We also demonstrated that the developed plate is potentially applicable to a variety of quantitative biochemical assays for qRT-PCR, Western blotting, and microplate-reader-based assays, such as ELISA, viability assay, and high content-screening (HCS) as well as the co-culture for biological studies. Human neural progenitor cells (hNPCs) that produce pathogenic Aβ species for modeling Alzheimer's disease (AD) were three-dimensionally cultured, and the efficacy of the inhibitors of Aβ production was assessed by ELISA in order to demonstrate the performance of this plate.

In this work, transfection of molecular beacons in traditional cell culture dishes and microfluidic cell culture systems with or without flows were comparatively studied by both computational and experimental methods. The comparison between static microfluidic systems and cell culture dishes reveals that the transfection of molecular beacons is controlled by both diffusion and reaction. The study on the microfluidic system with a range of fluid shear stresses and mass transfer rates implies that under high levels of shear stress the disruption of the binding between transfection reagent/molecular beacon complexes and cell membrane is dominant over the enhanced mass transfer.

We have investigated a confocal fluorescence detection system for 3D cultured mammalian cells in a microfluidic cell culture analog system. For direct measurement of metabolic changes in the microfluidic cell culture systems using 3D cell cultures, we constructed a compact and portable confocal fluorescence detection system based on discrete optical components. The confocal detection system was designed to provide a depth scan in situ without lateral imaging for fast scanning and acquisition of average fluorescence variation associated with a large number of cells in 3D cultures of microfluidic devices. The results were consistent with the data obtained by a standard confocal microscope and suggest the potential for monitoring cell dynamics in 3D cell-based assays.

Three-dimensional (3D) cell culture has developed rapidly over the past 5-10 years with the goal of better replicating human physiology and tissue complexity in the laboratory. Quantifying cellular responses is fundamental in understanding how cells and tissues respond during their growth cycle and in response to external stimuli. There is a need to develop and validate tools that can give insight into cell number, viability, and distribution in real-time, nondestructively and without the use of stains or other labelling processes. Impedance spectroscopy can address all of these challenges and is currently used both commercially and in academic laboratories to measure cellular processes in 2D cell culture systems. However, its use in 3D cultures is not straight forward due to the complexity of the electrical circuit model of 3D tissues. In addition, there are challenges in the design and integration of electrodes within 3D cell culture systems. Researchers have used a range of strategies to implement impedance spectroscopy in 3D systems. This review examines electrode design, integration, and outcomes of a range of impedance spectroscopy studies and multiparametric systems relevant to 3D cell cultures. While these systems provide whole culture data, impedance tomography approaches have shown how this technique can be used to achieve spatial resolution. This review demonstrates how impedance spectroscopy and tomography can be used to provide real-time sensing in 3D cell cultures, but challenges remain in integrating electrodes without affecting cell culture functionality. If these challenges can be addressed and more realistic electrical models for 3D tissues developed, the implementation of impedance-based systems will be able to provide real-time, quantitative tracking of 3D cell culture systems.

PurposeTwo-dimensional (2D) cell culture is a valuable method for cell-based research but can provide unpredictable, misleading data about in vivo responses. In this study, we created a three-dimensional (3D) cell culture environment to mimic tumor characteristics and cell-cell interactions to better characterize the tumor formation response to chemotherapy.Materials and methodsWe fabricated the 3D cell culture samples using a 3D cell bio printer and the bladder cancer cell line 5637. T24 cells were used for 2D cell culture. Then, rapamycin and Bacillus Calmette-Guérin (BCG) were used to examine their cancer inhibition effects using the two bladder cancer cell lines. Cell-cell interaction was measured by measuring e-cadherin and n-cadherin secreted via the epithelial-mesenchymal transition (EMT).ResultsWe constructed a 3D cell scaffold using gelatin methacryloyl (GelMA) and compared cell survival in 3D and 2D cell cultures. 3D cell cultures showed higher cancer cell proliferation rates than 2D cell cultures, and the 3D cell culture environment showed higher cell-to-cell interactions through the secretion of E-cadherin and N-cadherin. Assessment of the effects of drugs for bladder cancer such as rapamycin and BCG showed that the effect in the 2D cell culture environment was more exaggerated than that in the 3D cell culture environment.ConclusionsWe fabricated 3D scaffolds with bladder cancer cells using a 3D bio printer, and the 3D scaffolds were similar to bladder cancer tissue. This technique can be used to create a cancer cell-like environment for a drug screening platform.

Microfluidic assay-based optical measurement techniques for cell analysis: A review of recent progress.

The healing process of diabetic foot ulcers (DFUs) presents a slow pattern with an increased risk of infections, ischemia, and thrombosis correlated with high levels of reactive oxygen species production. Vascular injury is one of the factors contributing to the difficulty of wound healing in diabetic patients. Although the understanding of the pathophysiology of DFUs has significantly increased in recent years, associated treatments still have a high level of failure, leading to high morbidity rates, mortality, and amputations. Three-dimensional (3D) cell culture platforms offer a new approach to investigating and treating these wounds, as they can reproduce one or more physiological systems in a relevant microenvironment. This systematic review describes the advancements, challenges, and future implications of advanced 3D culture models in vascularization, encompassing pathophysiological understanding, treatment, and prognostic perspectives. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. This work was registered under PROSPERO protocol number CRD42022336473. The eligibility criteria addressed studies related to chronic DFUs that analyzed vascularization during the healing process. The selected study designs involved 3D cultures and organ-on-a- chip (OoC) platforms, utilizing either primary or secondary human cell lines. Studies published more than 10 years ago or using only animal cells in 2D culture environments were excluded. The search was conducted in PubMed, LILACS, Embase, MEDLINE, IEEE, the BSV regional portal, ScienceDirect, Scopus, CINAHL, EBSCO, and Web of Science. A total of 2,539 relevant studies were identified as of June 1, 2025. After screening, only seven met the inclusion criteria. These studies reflect a growing interest in using hydrogel scaffolds and microfluidic systems to replicate diabetic skin environments; however, the field remains in an early stage of development. OoC platforms, in particular, stand out for their ability to recreate dynamic, tissue-like conditions and vascular function. While some promising attempts have been made to combine hydrogels with these technologies, the evidence is still limited and inconclusive for chronic wound modeling. This review underscores both the potential and the urgent need for more robust and translational research in this area—especially toward building personalized, clinically relevant models to support future drug testing and therapeutic innovation.

Mammalian cells cultured on 2D surfaces in microfluidic channels are increasingly used in drug development and biological research applications. These systems would have more biological or clinical relevance if the cells exhibit 3D phenotypes similar to the cells in vivo. We have developed a microfluidic channel based system that allows cells to be perfusion-cultured in 3D by supporting them with adequate 3D cell-cell and cell-matrix interactions. The maximal cell-cell interaction was achieved by perfusion-seeding cells through an array of micropillars; and 3D cell-matrix interactions were achieved by a polyelectrolyte complex coacervation process to form a thin layer of matrix conforming to the 3D cell shapes. Carcinoma cell lines (HepG2, MCF7), primary differentiated (hepatocytes) and primary progenitor cells (bone marrow mesenchymal stem cells) were perfusion-cultured for 72 hours to 1 week in the microfluidic channel, which preserved their 3D cyto-architecture and cell-specific functions or differentiation competence. This transparent 3D microfluidic channel-based cell culture system also allows direct optical monitoring of cellular events for a wide range of applications.

A portable fluorescence optical detection system was developed to demonstrate real-time in situ analysis of cells that are three-dimensionally cultured in an extracellular matrix under microfluidic environment. The system was designed to provide a large field of view in the lateral plane to average out cellular processes in an axial layer and simultaneously diffraction-limited axial resolution. In this proof-of-concept study, the detection system was applied to quantitative analyses of short-term measurements of cell staining and cell cytotoxicity and long-term monitoring of a cell-invasion assay. For assays, colon cancer cells were cultured in a Matrigel or alginate matrix. The measured data were largely consistent with predicted results and revealed quantitatively cell dynamics specific to 3D cell cultures. The detection system has a potential as a single package to investigate 3D cultures in a microfluidic system.

Although the recent advances in stem cell engineering have gained a great deal of attention due to their high potential in clinical research, the applicability of stem cells for preclinical screening in the drug discovery process is still challenging due to difficulties in controlling the stem cell microenvironment and the limited availability of high-throughput systems. Recently, researchers have been actively developing and evaluating three-dimensional (3D) cell culture-based platforms using microfluidic technologies, such as organ-on-a-chip and organoid-on-a-chip platforms, and they have achieved promising breakthroughs in stem cell engineering. In this review, we start with a comprehensive discussion on the importance of microfluidic 3D cell culture techniques in stem cell research and their technical strategies in the field of drug discovery. In a subsequent section, we discuss microfluidic 3D cell culture techniques for high-throughput analysis for use in stem cell research. In addition, some potential and practical applications of organ-on-a-chip or organoid-on-a-chip platforms using stem cells as drug screening and disease models are highlighted.

In Vitro three-dimensional (3D) cell culture tools for spheroid and organoid models.

WITHDRAWN: In Vitro three-dimensional (3D) cell culture tools for spheroid and organoid models

In vitro models are necessary to study the pathophysiology of the disease and the development of effective, tailored treatment methods owing to the complexity and heterogeneity of breast cancer and the large population affected by it. The cellular connections and tumor microenvironments observed in vivo are often not recapitulated in conventional two-dimensional (2D) cell cultures. Therefore, developing 3D in vitro models that mimic the complex architecture and physiological circumstances of breast tumors is crucial for advancing our understanding of the illness. A 3D scaffold-free in vitro disease model mimics breast cancer pathophysiology by allowing cells to self-assemble/pattern into 3D structures, in contrast with other 3D models that rely on artificial scaffolds. It is possible that this model, whether applied to breast tumors using patient-derived primary cells (fibroblasts, endothelial cells, and cancer cells), can accurately replicate the observed heterogeneity. The complicated interactions between different cell types are modelled by integrating critical components of the tumor microenvironment, such as the extracellular matrix, vascular endothelial cells, and tumor growth factors. Tissue interactions, immune cell infiltration, and the effects of the milieu on drug resistance can be studied using this scaffold-free 3D model. The scaffold-free 3D in vitro disease model for mimicking tumor pathophysiology in breast cancer is a useful tool for studying the molecular basis of the disease, identifying new therapeutic targets, and evaluating treatment modalities. It provides a more physiologically appropriate high-throughput platform for screening large compound library in a 96–384 well format. We critically discussed the rapid development of personalized treatment strategies and accelerated drug screening platforms to close the gap between traditional 2D cell culture and in vivo investigations.Graphical

Stem cell-based tissue engineering shows enormous potential for regenerative medicine. Three-dimensional (3D) stem cell culture is the most basic aspect of tissue engineering. However, achievement of a perfect scaffold for highly efficient 3D cell culture is currently still limited. Herein, a new hyaluronic acid hydrogel dual-enzymatically crosslinked by horseradish peroxidase and choline oxidase is developed as a 3D stem cell culture system. This hydrogel possesses superior stability over two months, controllable biodegradability with hyaluronidases, a high swelling ratio exceeding 6000%, and excellent cytocompatibility in vitro and biocompatibility in vivo. More importantly, a long-time and highly cellular activity 3D culture of bone marrow-derived mesenchymal stem cells was achieved in vitro over 20 days. All these encouraging results highlight the great potential of this new hydrogel for 3D culture and tissue engineering.

The study of cell biology via monolayer cell culture systems is not entirely adequate for the investigation of complex inter-cell and cell to extracellular matrix interactions in vitro. Three dimensional (3D) cell culture systems better mimic more complex interactions and are extremely useful in broad applications of cell biology. In human cancer biology, a 3D culture system is better able to simulate an extracellular microenvironment to study tumor cell progression and sensitivity to anticancer agents. However, variability in forming spheres has been a persistent problem. This variability has been linked to medium composition and volume, cell density, duration in culture, and most importantly, the cellular interactions with the culture dish itself. Here, we hypothesize that a hydrophilic polymer coated surface, Thermo Scientific Nunclon Sphera, inhibits cell attachment to the culture dish by blocking binding of the extracellular matrix (ECM). First we demonstrated that the adsorption of ECM proteins (e.g. Collagen I and Fibronectin) to the hydrophilic polymer coated Nunclon Sphera surface is extremely low compared to that of the standard cell culture-treated surface, implying minimal interactions between the hydrophilic polymer and the ECM. We then examined spheroid formation on the hydrophilic polymer surface in comparison to the standard cell culture treated surface. We were able to show that unlike the standard cell culture surface, the hydrophilic polymer surface was able to support spheroid development in suspension with virtually no cell attachment by several cancer cell lines including HeLa, MCF-7, HepG2, Panc-1, Saos-2, and A549. In order to show that the hydrophilic polymer coating has no deleterious effects on cell growth, we conducted spheroid culture of a cancer stem cell line, P19.CL6, in the Nunclon Sphera dishes at relatively low cell seeding densities. Over time, the spheroids of all initial seeding densities were able to grow in volume, indicating that the hydrophilic polymer coating has no adverse effect on cell survival and proliferation. Finally, we demonstrated that the performance of Nunclon Sphera surface in supporting cancer spheroid formation is comparable to that of a similar product by a different manufacturer. Overall, the data supports that the Thermo Scientific Nunclon Sphera provides a consistent and reliable culture system for non-adherent spheroid growth, aiding in three dimensional modeling of cancer cells in vitro. Citation Format: Cindy Neeley, Louise Gaarn, Tina Marwood, Robert Scott, Stephanie Carter, Joseph Granchelli. A novel cell culture surface supports effective formation of three dimensional cancer spheroids in suspension. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 208. doi:10.1158/1538-7445.AM2013-208