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Chemotaxis model for human breast cancer cells based on signal-to-noise ratio [article]

Seongjin Lim, Hyeono Nam, Jessie Sungyun Jeon
2018 bioRxiv   pre-print
Chemotaxis, a biased migration of cells under a chemical gradient, plays a significant role in diverse biological phenomena including cancer metastasis. Stromal cells release signaling proteins to induce chemotaxis, which further causes organ-specific metastasis. Epidermal growth factor (EGF) is an example of the chemical attractants, and its gradient stimulates metastasis of breast cancer cells. Hence, the interactions between EGF and breast cancer cells have long been a subject of interest
more » ... oncologists and clinicians. However, most current approaches do not systematically separate the effects of gradient and absolute concentration of EGF on chemotaxis of breast cancer cells. In this work, we develop a theoretical model based on signal-to-noise ratio to represent stochastic properties and report our microfluidic experiments to verify the analytical predictions from the model. The results demonstrate that even under the same EGF concentration gradients, breast cancer cells can reveal distinct chemotaxis patterns at different absolute concentrations. Moreover, we found that addition of EGF receptor antibody can promote chemotaxis at a low EGF level. This apparently counterintuitive finding suggests that EGF receptor-targeted therapy may stimulate metastasis of breast cancer at a particular condition, which should be considered in anticancer drug design.
doi:10.1101/292300 fatcat:mtjxv7eejbbhpl3miuwh3gxu5i

Chemotaxis Model for Breast Cancer Cells Based on Signal/Noise Ratio

Seongjin Lim, Hyeono Nam, Jessie S Jeon
2018 Biophysical Journal  
Chemotaxis, a biased migration of cells under a chemical gradient, plays a significant role in diverse biological phenomena including cancer metastasis. Stromal cells release signaling proteins to induce chemotaxis, which leads to organ-specific metastasis. Epidermal growth factor (EGF) is an example of the chemical attractants, and its gradient stimulates metastasis of breast cancer cells. Hence, the interactions between EGF and breast cancer cells have long been a subject of interest for
more » ... ogists and clinicians. However, most current approaches do not systematically separate the effects of gradient and absolute concentration of EGF on chemotaxis of breast cancer cells. In this work, we develop a theoretical model based on signal/noise ratio to represent stochastic properties and report our microfluidic experiments to verify the analytical predictions from the model. The results demonstrate that even under the same EGF concentration gradients (0-50 or 0-150 ng/mL), breast cancer cells reveal a more evident chemotaxis pattern when the absolute EGF concentrations are low. Moreover, we found that reducing the number of EGF receptors (EGFRs) with addition of EGFR antibody (1 ng/mL) can promote chemotaxis at an EGF gradient of 0-1 ng/mL as shown by chemotaxis index (0.121 ± 0.037, reduced EGFRs vs. 0.003 ± 0.041, control). This counterintuitive finding suggests that EGFR-targeted therapy may stimulate metastasis of breast cancer because the partial suppression of the receptors makes the number of receptors close to the optimal one for chemotaxis. This analysis should be considered in anticancer drug design.
doi:10.1016/j.bpj.2018.09.028 pmid:30366624 pmcid:PMC6303234 fatcat:zd5usjozsbed7p3ndx5byh3c2y

Reagent- and actuator-free analysis of individual erythrocytes using three-dimensional quantitative phase imaging and capillary microfluidics [article]

DongHun Ryu, Hyeono Nam, Jessie Sungyun Jeon, YongKeun Park
2021 bioRxiv   pre-print
Histopathological examination of blood cells plays a crucial role in the diagnosis of various diseases. However, it involves time-consuming and laborious staining procedures required for microscopic review by medical experts and is not directly applicable for point-of-care diagnosis in resource-limited locations. This study reports a dilution-, actuation- and label-free method for the analysis of individual red blood cells (RBCs) using a capillary microfluidic device and quantitative phase
more » ... ng. Blood, without any sample treatment, is directly loaded into a micrometer-thick channel such that it forms a quasi-monolayer inside the channel. The morphological and biochemical properties of RBCs, including hemoglobin concentration, hemoglobin content, and corpuscular volume, were retrieved using the refractive index tomograms of individual RBCs measured using 3D quantitative phase imaging. The deformability of individual RBCs was also obtained by measuring the dynamic membrane fluctuations. The proposed framework applies to other imaging modalities and biomedical applications, facilitating rapid and cost-effective diagnosis and prognosis of diseases.
doi:10.1101/2021.05.15.442583 fatcat:okver3jpxjdjlpfi6vz3y3vroi

Efficient Capture and Raman Analysis of Circulating Tumor Cells by Nano-Undulated AgNPs-rGO Composite SERS Substrates

Jong-Eun Park, Nuri Oh, Hyeono Nam, Ji-Ho Park, Sanha Kim, Jessie S. Jeon, Minyang Yang
2020 Sensors  
The analysis of circulating tumor cells (CTCs) in the peripheral blood of cancer patients is critical in clinical research for further investigation of tumor progression and metastasis. In this study, we present a novel surface-enhanced Raman scattering (SERS) substrate for the efficient capture and characterization of cancer cells using silver nanoparticles-reduced graphene oxide (AgNPs-rGO) composites. A pulsed laser reduction of silver nanowire-graphene oxide (AgNW-GO) mixture films induces
more » ... ot-spot formations among AgNPs and artificial biointerfaces consisting of rGOs. We also use in situ electric field-assisted fabrication methods to enhance the roughness of the SERS substrate. The AgNW-GO mixture films, well suited for the proposed process due to its inherent electrophoretic motion, is adjusted between indium tin oxide (ITO) transparent electrodes and the nano-undulated surface is generated by applying direct-current (DC) electric fields during the laser process. As a result, MCF7 breast cancer cells are efficiently captured on the AgNPs-rGO substrates, about four times higher than the AgNWs-GO films, and the captured living cells are successfully analyzed by SERS spectroscopy. Our newly designed bifunctional substrate can be applied as an effective system for the capture and characterization of CTCs.
doi:10.3390/s20185089 pmid:32906807 fatcat:htuwk3hrtrbyhdzd3z63pg27ea

Recycling silver nanoparticle debris from laser ablation of silver nanowire in liquid media toward minimum material waste

June Sik Hwang, Jong-Eun Park, Gun Woo Kim, Hyeono Nam, Sangseok Yu, Jessie S. Jeon, Sanha Kim, Huseung Lee, Minyang Yang
2021 Scientific Reports  
AbstractAs silver nanowires (Ag NWs) are usually manufactured by chemical synthesis, a patterning process is needed to use them as functional devices. Pulsed laser ablation is a promising Ag NW patterning process because it is a simple and inexpensive procedure. However, this process has a disadvantage in that target materials are wasted owing to the subtractive nature of the process involving the removal of unnecessary materials, and large quantities of raw materials are required. In this
more » ... , we report a minimum-waste laser patterning process utilizing silver nanoparticle (Ag NP) debris obtained through laser ablation of Ag NWs in liquid media. Since the generated Ag NPs can be used for several applications, wastage of Ag NWs, which is inevitable in conventional laser patterning processes, is dramatically reduced. In addition, electrophoretic deposition of the recycled Ag NPs onto non-ablated Ag NWs allows easy fabrication of junction-enhanced Ag NWs from the deposited Ag NPs. The unique advantage of this method lies in using recycled Ag NPs as building materials, eliminating the additional cost of junction welding Ag NWs. These fabricated Ag NW substrates could be utilized as transparent heaters and stretchable TCEs, thereby validating the effectiveness of the proposed process.
doi:10.1038/s41598-021-81692-9 pmid:33500481 fatcat:nwuptpb42zhlba3trvlizvalpy

Table of Contents

2019 2019 IEEE 13th International Conference on Nano/Molecular Medicine & Engineering (NANOMED)  
High-Throughput Microfluidic 3D Cytotoxicity Assay for Cancer Immunotherapy (CACI-IMPACT Platform) 129 Yunchan Hwang Directional Migration of Cancer Cells Under Oxygen Tension Gradient 130 Hyeono  ...  Lai Peptide-based Immunological Cloaking for Efficient In vivo Phage Therapy 78 Yoon Sung Nam Multi-functional Hydrogel-incorporated Nanofiber Scaffolds Capable of Controlled Release of Growth  ... 
doi:10.1109/nanomed49242.2019.9130620 fatcat:xgquijr23rf5dlm354zctinr4a

Kimdaejung Convention Center

2019 2019 IEEE 13th International Conference on Nano/Molecular Medicine & Engineering (NANOMED)  
Speaker Bio-Hyeono Nam is a Ph.D. candidate in the department of mechanical engineering at KAIST.  ...  SS7 Smart Biomaterials for Bio/Nano-Applications Speaker Bio-Yoon Sung Nam is an associate professor of Materials Science and Engineering at KAIST.  ... 
doi:10.1109/nanomed49242.2019.9130603 fatcat:wlmmq4uwyjablibepjnazw4fp4