Toxicologie environnementale et analytique

Regeneration of Limbal Stem Cells in the Presence of Silver and Gold Nanoparticles

Abstract

Melinda Turani, Gaspar Banfalvi, Krisztina Kukoricza, Judit Jakim, Istvan Pocsi, Adam Kemeny-Beke and Gabor Nagy

To evaluate the potential of silver and gold nanoparticles in the healing of cornea damages cell regeneration was tested. Corneal limbal cell regrowth and structural changes in chromatin structure were studied in the presence of silver (AgNPs, 10 nm) and gold nanoparticles (AuNPs, 100 nm). An in vitro cell scratch model served to follow limbal cell growth by long-term scanning micro-photography. AgNPs exerted only a moderate delay on cell regeneration. Low concentration (80 ppm) of AuNPs did not affect severely, 160 and 320 ppm extended the repopulation of limbal monolayer in a included: a) decondensed veil-like, b) fibrillary chromatin, c) supercoiled ribbon structures, d) visible chromosomes as chromatin bodies, e) early linear forms, and e) finally as metaphase chromosomes. Characteristic distortions in chromatin structures took place in nuclei in the presence of nanoparticles. Ag nanoparticles prevented the formation of linear and metaphase chromosomes. Gold particles (80 ppm) allowed the formation of chromatin bodies, but not more condensed chromosomal forms. Higher concentrations of AuNPs prevented the formation of ribboned chromatin and higher chromosomal structures. Results show that cell regeneration and chromatin toxicity are dose dependent. In spite of their lower size, Ag nanoparticles (10 nm) were less toxic than larger Au particles (100 nm).