Liver cancer immunoassay with magnetic nanoparticles and MgO-based magnetic tunnel junction sensors

This journal issue is proceedings of the 56th 56th Conference on Magnetism and Magnetic MaterialsSession DV - Sensors 2 (Poster Session): no. DV-07We have demonstrated the detection of alpha-fetoprotein (AFP) labeled with magnetic nanoparticles (MNPs) using MgO-based magnetic tunnel junction (MTJ) sensors. AFP is an important hepatic tumor biomarker and the detection of AFP has significant applications for clinical diagnostics and immunoassay for early-stage liver cancer indications. In this work, MgO-based MTJ sensors and 20-nm iron-oxide magnetic nanoparticles (MNPs) were used for detecting AFP antigens by a sandwich-assay configuration. The MTJ sensors with a sensing area of 4 × 2 μm 2 possess tunneling magnetoresistance (TMR) of 122 and sensitivity of 0.95/Oe at room temperature. The target AFP antigens of three concentrations were successfully detected, and the experimental data indicate that the resistance variations of the MTJ sensor increased with the AFP concentration ratios proportionally. These results demonstrate that MgO-based MTJ sensors together with MNPs are a promising biosensing platform for liver cancer immunoassay. © 2012 American Institute of Physics.published_or_final_versionThe 56th Conference on Magnetism and Magnetic Materials, Scottsdale, AZ., 30 October-3 November 2011. In Journal of Applied Physics, 2012, v. 111 n. 7, article no. 07E50

Liver cancer immunoassay with magnetic nanoparticles and MgO-based magnetic tunnel junction sensors

2011-2012 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Spreadsheet-based ultrasensitive magnetic field sensor design tool using Microsoft Excel

Poster: P1.2

Sterilization on Dextran-Coated Iron Oxide Nanoparticles: Effects of Filtration, Autoclaving, and Ethanol Treatment

Poster Session: no. 006Dextran-coated iron oxide magnetic nanoparticles (DMNPs) have attracted significant attention for their applications in biomedical area. For this purpose, DMNPs must be sterile, and several terminal sterilization methods can be used. However, very little is known regarding the effect of sterilization methods on the properties of DMNPs. We studied the influences of autoclaving on DMNPs colloids and investigated the effects of sterile filtration and chemical sterilization with ethanol by using TEM, UV-Vis spectroscopy, FT-IR spectroscopy, DLS, VSM, and in vitro cytotoxicity study. Our results indicate caution must be taken on the sterilization methods for DMNPs. Filter sterilization reduced the amount of DMNPs significantly. Autoclaving affected the physical properties of DMNPs, increasing their hydrodynamic sizes dramatically, and decreasing their saturation magnetization. The ethanol sterilization did not exhibit any effect on the DMNPs and it is more suitable to sterilize DMNPs

In vitro Cytotoxicity Study of Magnetic Iron Oxide Nanoparticles on Normal Human Cells (RPE) and Cancer Cells (HeLa)

Poster no. NANO-10

Effects of Nanoporous and Microgrooved Substrates on Cell Morphology and Cell Migration of Hepatoma Cells

Understanding the mechanism of how surface topography influences mammalian cells is important for the development of medical implants and tissue engineering. Although variety of cell types have been used in cell-substrate studies for different purposes, hepatocytes have been paid relatively less attention. In this study, we investigated the influences of nanopores and microgrooves on the morphology and migration of hepatoma cell line, BEL-7402 cells. The cells were cultured on different synthetic substrates including flat cell culture plate, flat silicon wafer sputtered with alumina, nanoporous (140 nm in diameter) anodized aluminum membrane (AAM) surface, flat polydimethylsiloxane (PDMS), and PDMS patterned with microgrooves of various widths (10 μm, 30 μm and 50 μm in width, and 2 μm in depth). Cellular behaviour on these surfaces was studied using fluorescent microscopy, time lapse microscopy and scanning electron microscopy (SEM)

Effects of Nanoporous and Microgrooved Substrates on Cell Morphology and Cell Migration of Hepatoma Cells

Understanding the mechanism of how surface topography influences mammalian cells is important for the development of medical implants and tissue engineering. Although variety of cell types have been used in cell-substrate studies for different purposes, hepatocytes have been paid relatively less attention. In this study, we investigated the influences of nanopores and microgrooves on the morphology and migration of hepatoma cell line, BEL-7402 cells. The cells were cultured on different synthetic substrates including flat cell culture plate, flat silicon wafer sputtered with alumina, nanoporous (140 nm in diameter) anodized aluminum membrane (AAM) surface, flat polydimethylsiloxane (PDMS), and PDMS patterned with microgrooves of various widths (10 μm, 30 μm and 50 μm in width, and 2 μm in depth). Cellular behaviour on these surfaces was studied using fluorescent microscopy, time lapse microscopy and scanning electron microscopy (SEM)

Sterilization on dextran-coated iron oxide nanoparticles: Effects of autoclaving, filtration, UV irradiation, and ethanol treatment

Dextran-coated magnetic iron oxide nanoparticles (DMNPs) have attracted significant attention for their many applications in biomedical area such as diagnostic magnetic resonance imaging (MRI), and gene therapy. For biomedical applications, nanoparticles must be sterile, and several terminal sterilization methods can be used. However, very little is known regarding the effect of sterilization methods on the properties of DMNPs. It is crucial to find out whether the DMNPs are affected by the sterilization process. This paper reported the influences on the physicochemical properties of DMNPs from four different methods: autoclaving, sterile filtration, UV irradiation and chemical sterilization with ethanol. In addition, cell viability was also studied. Our results indicate that filter sterilization changes the iron oxide/dextran ratio in DMNPs sample significantly. Besides, the autoclaving and ethanol treatment affected the polydispersity index of DMNPs sample. Thus, caution must be taken when choosing an appropriate method to perform sterilization for DMNPs. © 2013 Elsevier B.V. All rights reserved

HIV Disease Detection Platform with Magnetic Nanoparticles and MgO-Based Magnetic Tunnel Junction Sensors

Poster Presentation: no. P81