Articles by Yeonho Jo in JoVE
Synthesis of Multi-walled Carbon Nanotubes Modified with Silver Nanoparticles and Evaluation of Their Antibacterial Activities and Cytotoxic Properties Youngmin Seo*1, Chanhwi Park*2, Jaewoo Son2, Kyungwoo Lee2, Jangsun Hwang2, Yeonho Jo2, Dohyun Lee2, Muhammad Saad Khan2, Sachin Ganpat Chavan2, Yonghyun Choi2, Dasom Kim2, Assaf A Gilad3, Jonghoon Choi2 1Center for Biomaterials, Biomedical Research Institute, Korea Institute of Science and Technology, 2School of Integrative Engineering, Chung-Ang University, 3Division of Synthetic Biology and Regenerative Medicine, Institute for Quantitative Health Science and Engineering, Michigan State University In this study, antimicrobial nanomaterials were synthesized by acidic oxidation of multiwalled carbon nanotubes and subsequent reductive deposition of silver nanoparticles. Antimicrobial activity and cytotoxicity tests were performed with the as-prepared nanomaterials.
Other articles by Yeonho Jo on PubMed
Aptamer-conjugated Live Human Immune Cell Based Biosensors for the Accurate Detection of C-reactive Protein Scientific Reports. | Pubmed ID: 27708384 C-reactive protein (CRP) is a pentameric protein that is present in the bloodstream during inflammatory events, e.g., liver failure, leukemia, and/or bacterial infection. The level of CRP indicates the progress and prognosis of certain diseases; it is therefore necessary to measure CRP levels in the blood accurately. The normal concentration of CRP is reported to be 1-3 mg/L. Inflammatory events increase the level of CRP by up to 500 times; accordingly, CRP is a biomarker of acute inflammatory disease. In this study, we demonstrated the preparation of DNA aptamer-conjugated peripheral blood mononuclear cells (Apt-PBMCs) that specifically capture human CRP. Live PBMCs functionalized with aptamers could detect different levels of human CRP by producing immune complexes with reporter antibody. The binding behavior of Apt-PBMCs toward highly concentrated CRP sites was also investigated. The immune responses of Apt-PBMCs were evaluated by measuring TNF-alpha secretion after stimulating the PBMCs with lipopolysaccharides. In summary, engineered Apt-PBMCs have potential applications as live cell based biosensors and for in vitro tracing of CRP secretion sites.
Sensitive Detection of Copper Ions Via Ion-responsive Fluorescence Quenching of Engineered Porous Silicon Nanoparticles Scientific Reports. | Pubmed ID: 27752120 Heavy metal pollution has been a problem since the advent of modern transportation, which despite efforts to curb emissions, continues to play a critical role in environmental pollution. Copper ions (Cu), in particular, are one of the more prevalent metals that have widespread detrimental ramifications. From this perspective, a simple and inexpensive method of detecting Cu at the micromolar level would be highly desirable. In this study, we use porous silicon nanoparticles (NPs), obtained via anodic etching of Si wafers, as a basis for undecylenic acid (UDA)- or acrylic acid (AA)-mediated hydrosilylation. The resulting alkyl-terminated porous silicon nanoparticles (APS NPs) have enhanced fluorescence stability and intensity, and importantly, exhibit [Cu]-dependent quenching of fluorescence. After determining various aqueous sensing conditions for Cu, we demonstrate the use of APS NPs in two separate applications - a standard well-based paper kit and a portable layer-by-layer stick kit. Collectively, we demonstrate the potential of APS NPs in sensors for the effective detection of Cu.
Probing Characteristics of Cancer Cells Cultured on Engineered Platforms Simulating Different Microenvironments Artificial Cells, Nanomedicine, and Biotechnology. | Pubmed ID: 29519165 In this study, we demonstrate cell culture platforms that can provide a microenvironment similar to in vivo conditions so that in vivo-compatible drug testing results can be obtained from the in vitro experiments. To realize such in vivo microenvironment-mimetic platforms, different culture platforms such as a three-dimensional (3D) cell aggregate film, fluidic environment within a microfluidic system or extracellular matrix (ECM) coating were established. The tumor cell growth rate and sensitivity to doxorubicin (DOX) were studied using the glioblastoma cell line T98G. When 3 D spheroids were cultured, they grew significantly slower than under other culture conditions. When the cells were treated with DOX, the anticancer drug could not efficiently penetrate the 3 D spheroids to inhibit cell growth. When cultured on the Matrigel-coated culture vessel, T98G cells grew even in the presence of DOX, demonstrating chemoresistance. Nonetheless, in the 2D culture plate and in the microfluidic chip, cell growth decreased with DOX treatment and the binding ability was lost. These results indicate that the cells reacted differently to the same anticancer drug depending on the culture microenvironment. We believe that the development of a more physiologically relevant tumor cell culture platform will lead to more reliable antitumor drug responses.