Publications by authors named "Kin-Fong Lei"

This review explores the significant role of microfluidic technologies in advancing cancer research, focusing on the below key areas: droplet-based microfluidics, organ-on-chip systems, paper-based microfluidics, electrokinetic chips, and microfluidic chips for the study of immune response. Droplet-based microfluidics allows precise manipulation of cells and three-dimensional microtissues, enabling high-throughput experiments that reveal insights into cancer cell migration, invasion, and drug resistance. Organ-on-chip systems replicate human organs to assess drug efficacy and toxicity, particularly in the liver, heart, kidney, gut, lung, and brain.

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  • Liver cancer is a major global health issue, resistant to standard treatments like chemotherapy, prompting the need for improved evaluation methods for combination therapies.
  • A new hydrogel-based microfluidic platform was developed to test drug effects on liver cancer tumor spheroids, allowing for precise measurement of drug responses and identification of effective drug combinations through innovative visualization techniques.
  • This platform replicates real-life tumor conditions and offers a quick way to screen drugs, potentially leading to better treatment strategies in clinical settings.
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In native tissues, cells encounter a diverse range of stiffness, which can significantly affect their behavior and function. The ability of cells to sense and respond to these mechanical cues is essential for various physiological processes, including cell migration. Cell migration is a complex process influenced by multiple factors, with substrate stiffness emerging as a critical determinant.

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  • The study focuses on developing a folding paper system that mimics the native tumor microenvironment to better understand cancer metastasis.
  • This system allows cancer cells to grow under conditions similar to solid tumors, enabling researchers to observe cell migration and identify differentiating traits based on their movements.
  • Gene expression analysis revealed links between cancer cell migration and various biological processes, highlighting the system's potential for studying aggressive cancer characteristics and molecular pathways involved in metastasis.
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The development of micro- and nanotechnology for biomedical applications has defined the cutting edge of medical technology for over three decades, as advancements in fabrication technology developed originally in the semiconductor industry have been applied to solving ever-more complex problems in medicine and biology. These technologies are ideally suited to interfacing with life sciences, since they are on the scale lengths as cells (microns) and biomacromolecules (nanometers). In this paper, we review the state of the art in bionanotechnology and bioMEMS (collectively BNM), including developments and challenges in the areas of BNM, such as microfluidic organ-on-chip devices, oral drug delivery, emerging technologies for managing infectious diseases, 3D printed microfluidic devices, AC electrokinetics, flexible MEMS devices, implantable microdevices, paper-based microfluidic platforms for cellular analysis, and wearable sensors for point-of-care testing.

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  • Periosteum-derived progenitor cells (PDPCs) and adipose-derived stem cells (ADSCs) play crucial roles in bone healing, and co-culturing them can create a microenvironment for studying their interaction.
  • A novel paper-based osteogenesis-on-a-chip platform was developed to facilitate a 3D co-culture model of PDPCs and ADSCs, allowing the study of growth factors and cellular communication.
  • The research utilizes this platform to analyze the effects of various growth factors on PDPC osteogenesis, potentially leading to advancements in bone regeneration therapies.
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When tumor cells are released from a primary tumor into the bloodstream or lymphatic circulation system, they are exposed to a continuous shear flow environment. This environment exerts physical stresses on the tumor cells, which can activate apoptotic pathways. However, certain tumor cells have the ability to adapt to these mechanical stresses, enhancing their likelihood of survival and promoting metastasis.

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Electrical impedance biosensors are powerful and continuously being developed for various biological sensing applications. In this line, the sensitivity of impedance biosensors embedded with microfluidic technologies, such as sheath flow focusing, dielectrophoretic focusing, and interdigitated electrode arrays, can still be greatly improved. In particular, reagent consumption reduction and analysis time-shortening features can highly increase the analytical capabilities of such biosensors.

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  • High mortality rates in cancer patients with distant metastasis highlight the need for targeted drugs to inhibit cancer spread.
  • A novel folding paper system was created to mimic tumor-vascular interactions and study long-distance cell migration, revealing significant correlations between migration distance and metastasis-related genes.
  • Further analysis showed that the PTPN13 gene acts as a tumor suppressor that inhibits long-distance cell migration, offering insights for potential targeted therapies against cancer metastasis.
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This work describes a facile fabrication of an efficient electrochemical sensor utilizing sonication-derived Galinstan nanoparticles (Galinstan NPs) interfaced to annealed dirhenium heptoxide (ReO) thin-film on Silicon (Si) for the quantitative detection of the most promising acute renal disease biomarker Neutrophil Gelatinase Associated Lipocalin (NGAL). Under optimized preconditions, the anti-NGAL antibodies were immobilized on the Galinstan NPs/ReO/Si electrode by carbodiimide crosslinking to detect NGAL. The composition, morphology, and structural properties of the electrode were elucidated by various physical characterizations.

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pH monitoring in clinical assessment is pivotal as pH imbalance significantly influences the physiological and extracellular functions of the human body. Metal oxide based pH sensors, a promising alternative to bulky pH electrodes, mostly require complex fabrication, high-temperature post-deposition treatment, and high expenses that inhibit their practical applicability. So, there is still room to develop a straightforward and cost-effective metal oxide based pH sensor comprising high sensitivity and reliability.

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The early detection of lipocalin 2 (LCN 2), a biomarker to diagnose acute kidney injury (AKI) and its consequences leading to renal failure, is highly challenging due to the lack of proper investigating tools. To overcome this issue, we developed nickel oxide nanoparticles modified cerium copper oxide (NiO Nps/CeCuO) thin film-based immunosensor to determine the presence of LCN 2 in the analyte. The sol-gel deposited CeCuO (on a silicon (Si) substrate) was post-annealed at different temperatures (700 °C, 800 °C, and 900 °C), where 800 °C showed the optimum electrochemical performance.

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Background: Rotator cuff (RC) tendinopathy is one of the most common causes of shoulder pain. Platelet-rich plasma (PRP) has been frequently used in clinical scenarios, but its efficacy remains inconsistent.

Purpose: To investigate the different responses of human tenocytes from torn RCs to leukocyte-rich PRP (LR-PRP) and leukocyte-poor PRP (LP-PRP) in a 2-chamber coculture device.

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Cancer stem cells (CSCs) were reported to play important roles in cancer initialization, progression, and metastasis. In order to study the variation between CSCs and non-CSCs, single-cell analysis is conducted but technically complicated. In the current work, a microwell array made by an agarose hydrogel was developed for the study of a CSC-derived single colony.

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  • Hypoxia is a low oxygen condition often found in malignant tumors, triggering complex signaling pathways in cancer cells that contribute to tumor growth and metastasis.
  • A novel paper-based solid tumor model was developed by folding filter paper with cultured cancer cells, allowing researchers to analyze cellular responses in different layers and reproduce an internal hypoxic environment.
  • This model showed increased expression of HIF1-α and VEGFA in the inner layer, leading to enhanced endothelial cell proliferation and migration, and enables further studies on tumor hypoxia and angiogenesis in a living system.
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Investigation of stem cell-like property in cancer cells is important for the development of new therapeutic drugs targeting at malignant tumors. Currently, the standard approach for identifying cancer stem cell-like cells relies on the recognition of stem cell surface markers. However, the reliability remains controversial among biologists.

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Cancer metastasis, that cancer cells migrate from primary to distance site, is the major cause of death for cancer patients. Investigation of the correlation between cell migration and extracellular stimulation is critical to develop effective therapy for suppressing cancer metastasis. However, the existing cell migration assays remain limitations to faithfully investigate cell migration capability.

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Cancer metastasis is the primary cause of high mortality of cancer patients. Enumeration of circulating tumor cells (CTCs) in the bloodstream is a very important indicator to estimate the therapeutic outcome in various metastatic cancers. The aim of this article is to review recent developments on the CTC isolation technologies in microdevices.

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To investigate tumor cell migration capability, the scratch/wound healing assay and the Transwell assay are the most commonly used assays in the current biomedical research laboratory. However, both assays have their limitations and may mislead the interpretation of the results. In the current study, visualization and quantification of tumor cell migration process was realized in a three-dimensional (3D) environment.

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Capacitive Micromachined Ultrasonic Transducer (CMUT) is a promising ultrasonic transducer in medical diagnosis and therapeutic applications that demand a high output pressure. The concept of a CMUT with an annular embossed pattern on a membrane working in collapse mode is proposed to further improve the output pressure. To evaluate the performance of an embossed CMUT cell, both the embossed and uniform membrane CMUT cells were fabricated in the same die with a customized six-mask sacrificial release process.

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Background: Growing evidence indicates that measures of body composition may be related to clinical outcomes in patients with malignancies. The aim of this study was to investigate whether measures of regional adiposity-including subcutaneous adipose tissue index (SATI) and visceral adipose tissue index (VATI)-can be associated with overall survival (OS) in Taiwanese patients with bone metastases.

Methods: This is a retrospective analysis of prospectively collected data.

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Nowadays, cancer disease is continuously identified as the leading cause of mortality worldwide. Cancer chemotherapeutic agents have been continuously developing to achieve high curative effectiveness and low side effects. However, solid tumors present the properties of low drug penetration and resistance of quiescent cells.

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  • Culturing cells in a 3D environment improves cancer research and chemotherapy evaluation but is often complicated and time-consuming.
  • A new microfluidic platform was created using a paper/polymer composite that allows for easy screening of cell viability and protein expression in response to chemical gradients.
  • This technique simplifies the process by enabling analysis of cellular responses to various stimuli (like drug gradients) on a single paper substrate, with results obtainable in about 1.5 hours.
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  • Local antibiotic application, commonly used in orthopedic surgery, can be toxic to periosteal tissues, affecting bone growth and cellular expression.
  • In experiments with periosteal cells from rabbits, various concentrations of antibiotics (cefazolin, ciprofloxacin, vancomycin) revealed significant dose-related inhibitions in cell proliferation and osteogenic marker expression.
  • Analysis showed a strong correlation between growth indicators and antibiotic dosages, highlighting the need to consider antibiotic impacts on bone health when used in surgical procedures.
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  • Older patients with metastatic cancer tend to have higher neutrophil-to-lymphocyte ratios (NLR) and lower overall survival (OS) rates compared to younger patients.
  • Research involving 3981 patients showed that a pretreatment NLR below the median is an independent indicator of better OS for both age groups.
  • Specifically for older patients, those with a low NLR who received systemic therapy had the best survival outcomes.
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