Biosensing Approaches for Rapid Genotoxicity and Cytotoxicity Assays upon Nanomaterial Exposure

Abstract

The increased utilization of nanomaterials could affect human health and the environment due to increased exposure. Several mechanisms regarding the negative effects of nanomaterials have been proposed, one of the most discussed being oxidative stress. Many studies have shown that some metal oxide nanoparticles can enhance reactive oxygen species generation, inducing oxidative stress, DNA damage, and unregulated cell signaling, and eventually leading to changes in cell motility, apoptosis, and even carcinogenesis. 8-Hydroxy-2'-deoxyguanosine (8-OHdG) is one of the predominant forms of oxidative DNA damage, and has therefore been widely used as a biomarker for oxidative stress and carcinogenesis. Ther are two major objectives to this study. Firstly, the development of a novel lateral flow immunoassay (LFIA) is presented to measure the concentration of 8-OHdG in cells and thus reveal the nanotoxicity on the genomic level. The feasibility of this new method is validated by comparison with two other established methods: Alamar Blue assay and a recently developed electrical impedance sensing (EIS) system on the level of cell proliferation/viability. Secondly, the toxicological effects of three metallic nanoparticles (CuO, CdO, and TiO2 ) are investigated and compared using these three methods with completely different mechanisms. The results show that there is a high variation among different nanoparticles concerning their ability to cause toxic effects. CuO nanoparticles are the most potent regarding cytotoxicity and DNA damage. CdO shows a fallen cell viability as well as DNA damage, however, to a lesser extent than CuO nanoparticles. TiO2 particles only cause very limited cytotoxicity, and there is no obvious increase in 8-OHdG levels. In conclusion, LFIA as well as the EIS system are useful methods for quantitative or qualitative nanotoxicity assessments with high sensitivity, specificity, speed of performance, and simplicity.

Biosensing of DNA oxidative damage: a model of using glucose meter for non-glucose biomarker detection

“…activity of the conjugates was tested through our previously published method. 17 As illustrated in Figure 3, competitive type strips are designed for testing small molecules with single antigenic determinants (ie, 8-OHdG), which cannot bind to two antibodies simultaneously. Both 8-OHdG in the sample solution and 8-hydroxyguanosine on the test line compete to bind to the Ab from the conjugation pad.…”

“…17 The Supplementary materials also include a detail instruction for the synthesis. For the conjugation, the AuNPs solution (~20 nm) was concentrated fivefold and the pH was adjusted to 8.5-9.0 with 0.1 M K 2 CO 3 in advance for labeling.…”

“…[1][2][3][4][5][6][7][8][9] Among them, paper-based POC devices are a special category due to the advantages of being simple, rapid, on-site, and cost-effective; they have been widely used in home health care and medical testing, [10][11][12] even environmental monitoring. [13][14][15] The lateral flow immunochromatographic assay, also called lateral flow test, is one of the simplest and most popular formats of paper-based POC devices and can be used to detect specific substances, including small molecules, [15][16][17][18] large proteins, [19][20][21] and even whole pathogens, 10 in a sample by using an immunological reaction. However, most of these tests are based on qualitative colorimetry, which is not sufficient in many cases.…”

“…The concept is demonstrated by using an oxidative DNA damage biomarker, 8-hydroxy-2′-deoxyguanosine (8-OHdG). The basic design of the device is adapted from our previously reported colorimetric visual detection platform 17 based on a gold nanoparticles (AuNPs)-based competitive immunoassay. However, visual detection can provide only qualitative and semiquantitative results.…”

Development of Point-of-Care Testing Sensors for Biomarker Detection

“…13,24,[163][164][165][166][167][168][169] Among them, paper-based POCT devices is a special category due to the advantages of being simple, rapid, on-site, and cost-effective; they have been widely used in home healthcare and medical testing, 56,61,138 even environmental monitoring. 39,40,170 LFS is one of the simplest and most popular formats of paper-based POCT devices, and can be used to detect specific substances including small molecules, 40,60,171,172 large proteins 15,58,173 and even whole pathogens, 138 in a sample by using an immunological reaction. However, most of these tests are based on qualitative colorimetry, which is not sufficient in many cases.…”