Sabancı University Nanotechnology Research and Application Center (SUNUM) Researchers Dr. Anjum Qureshi (SUNUM) and Dr. Javed H. Niazi’s “Probing size-dependent toxicity of nanomaterials on living microbial cells using lab-on-a-chip” titled project work has been highlighted in TUBITAK March 2018 bulletin.
Project highlights and findings:
The nanoparticles are rapidly becoming part of our daily life mainly because of their antibacterial and odor-fighting properties in many commercial products, such as cosmetics, toothpastes, sanitary-ware coatings, paints, wound-dressings, detergents, food packaging and even in medicine and drug delivery systems. Despite obvious benefits of these nanomaterials, there is a serious concern on their long-term impact on human health and environment due to their harmful or toxic effects.
The goal of this project was to probe size-dependent toxicity of nanomaterials on living microbial cells using lab-on-a-chip approach. The whole-cell biosensor (WCB) chip can respond to different nano-sizes and concentrations of nanomaterials through direct change in cellular behavior as capacitive/electrical signal. The schematic diagram below illustrates the interaction of nanoparticles with the bacterial cell under the AC electric field on developed lab-on-chip platform (Fig.1).
Fig.1. The schematic diagram illustrating the interaction of nanoparticles with the bacterial cell under the AC electric field on developed lab on a chip platform.
Our study demonstrated that toxicity of nanomaterials strictly depended on nano-size of materials, smaller the size of a nanoparticle, greater will be the toxicity on living cells. The extent of toxicity of nanomaterial also depends on type of cells, such as E. coli which is more sensitive to nanoparticles than the yeast cells.
Investigating the impacts of interactions between NPs and cell-surfaces through electrical and physical properties are important for interpreting toxicity data, and predicting the toxicity risks associated with engineered NPs. The most expensive methods employed todate for toxicity screening rely on fluorescence/colorimetric assays that are conventional techniques, also employed for validation in this project, only provided predictive assessments. The use of living microorganisms with normal cellular activity that are interfaced with electronic chips provided direct, real-time and specific biological information on the nature of NMs’ impact on living cells. Such type of information using the developed WCB chip to our knowledge, no other technique could provide. Thus, the developed WCB chip platform is a versatile tool for high throughput screening of not only NMs but could also for testing a wide range of chemicals, drugs or environmental contaminants. The potential advantages of the developed nanotoxicity assay and sensing platform include its ease of use, sensitivity, inherent selectivity which comes from the specificity of embedded microorganisms, versatility and its cost effectiveness.
The findings and results of this study has been published in many SCI journals and presented in various international conferences. All these credentials hold great promise in future of this technology in contributing to significant advances over conventional assays for determining the toxicity of NMs.