EXPERIMENTAL METHODS AND IN VITRO CYTOXICITY AND GENOTOXICITY OF NANOMATERIALS

Exposure to nanosized materials (specifically, materials with one dimension less than 100 nm) is nothing new. Humans have long been exposed to nanomaterials from various earth related processes, like forest fires and volcanoes, as well as naturally occurring events, such as sea spray. Due to the advent of modern nanotechnology research, however, the arrival of the industrial nanotechnology age is upon us where large quantities of various synthetic nanomaterials are formulated and exposed to humans on a daily basis. As such, there is an on-going need for more researchers to determine human and environmental toxicity of nanomaterials. This review paper will assess the current knowledge on the in vitro cytotoxicity and genotoxicity of nanomaterials while summarizing the exploration of nanotechnology within the specific world of biomaterials. An overview of material characterization studies as well as various biological assays currently used to evaluate cytotoxicity and genotoxicity will also be addressed. Specifically, after defining some basic definitions of biomaterials and biocompatibility, commonly used cytotoxicity assays are summarized, and some examples of nanomaterial cytotoxicity studies presented. Next, an understanding of genotoxicity assays and associated mechanisms with nanomaterials are presented. Finally, some future thoughts on nanobiomaterial (that is, nanomaterials used as biomaterials) cytotoxicity and genotoxicity are presented. Such an overview reflects a comprehensive effort to gain an understanding of the toxicity of nanobiomaterials at the molecular level requiring the use of a battery of toxicological assays. The purpose of this review article is to serve as reference for those new to the field of nanotoxicity and to encourage others to conduct accurate and meaningful nanotoxicity studies.