Genotoxicity of Nanocarriers.

Background: With the rapid development of nanoparticles in drug delivery system, a lot of interest in the genotoxicity evaluation of nanocarriers has emerged currently. Here our emphasis was placed on the summary of studies on standard genotoxicity assays.

Methods: We performed a PubMed/MEDLINE search for all publications in the English language related to assessment of genotoxicity of nanocarriers. A total of 45 publications were included. In these studies, the in vitro and in vivo Comet assay, in vitro and in vivo micronucleus assay, in vitro and in vivo Chromosomal Aberration (CA) assay, Ames test, phosphorylated histone H2Ax (γ-H2Ax) foci formation detection, 8-hydroxy-2'-deoxyguanosine (8-OHdG) assay, Sister Chromatid Exchange (SCE) assay, and mammalian cell mutation assay were all included.

Results: We figured out that the results of these assays were apparently inconsistent. More positive results of detecting genotoxicity of nanocarriers were generated via in vitro assays than in vivo assays. Besides, less in vitro positive outcomes turned out in detection of gene mutation than chromosome and DNA damage. Most of the mutagenicity tests for nanocarriers were negative.

Conclusion: To sum up, these inconsistent results on genotoxicity of nanocarriers indicate that there are great challenges regarding risk assessment and an urgent need to establishing a battery of standard measurements in the future.