CYTOXICITY AND GENOTOXICITY OF POLYSTYRENE NANOPARTICLES IN BOVINE OVIDUCTAL EPITHELIAL CELLS (BOEC).

Recently a great interest surrounds the development of nanoparticles (NPs) for potential biomedical applications such as drug delivery, cancer therapy and medical imaging. NP delivery system in vivo promises to overcome the epithelial barriers, key obstacle to the administration of drugs, vaccines, plasmid DNA and RNAi material. However, so far the interplay and hazards between nanoscale materials and biological systems have not been fully understood. Highlight of these data we have evaluated the effect of polystyrene nanoparticles (PS-NPs), widely used as model and reference particles, on primary culture of bovine oviductal epithelial cells (BOEC) that form a epithelial barrier of female reproductive tracts involved in the secretion of products essential for gametes and embryos. BOEC have been cultured with 44 nm fitc-PS-NPs 10ug/ml for 7 days until achievement of cell confluence and treated to study NP influence on the cellular proliferation and chromosomal arrangement, using also confocal microscope, and gene expression by differential display. The confocal analysis has not revealed the NP presence in the nucleus during cell division and the karyotype analysis has not showed stastistically significant chromosomal anomalies compared to control sample. However study of gene expression by differential display has exposed interesting alterations. Particularly, BOEC treated with NPs have showed the activation of expression of a band 100 bp and one of 600 bp. The sequencing has revealed an identity of 99% between the 100 bp band and Bos taurus microsatellite DNA clone RP42-69E7, whereas the 600 bp band shared and identity of 87% with Bos taurus breed Hereford chromosome 5 genomic scaffold (3517 bp at 5' side: GRAM domaincontaining protein 4 6521 bp at 3' side: ceramide kinase (CERK). Microsatellite sequences may occur within promoters and other cisregulatory regions, playing an important role in modulating of gene expression under stress. The phosphorylation of ceramide (C-1-P) via CERK has been shown to stimulate the production of signaling molecules of cell proliferation. Moreover the interaction of C-1-P with phosphatidylinositol 3-kinase/Akt and Mammalian target of rapamycin indicate that disregulated CERK expression may lead to cancer. Our results demonstrate that PS-NPs seem do not affect cell division and chromosomal rearrangement, but may interfere with gene expression and progression in cell cycle. Our data represent a preliminary new contribute to understand the complicated interactions and the effects between NPs and biological systems. However other studies are necessary before NP application in biomedical field.