Intracellular Localisation, Geno- and Cytotoxic Response of Poly N-isopropylacrylamide (PNIPAM) Nanoparticles to Human Keratinocyte (HaCaT) and Colon Cells (SW 480)

Pratap Naha, Dublin Institute of Technology
Kunal Bhattacharya, Dublin Institute of Technology
Tiziana Tenuta, University College Dublin
Kenneth Dawson, University College Dublin
Iseult Lynch, University College Dublin
Amaya Gracia, Dublin Institute of Technology
Fiona M. Lyng, Dublin Institute of Technology
Hugh J. Byrne, Dublin Institute of Technology

Document Type Article

In Toxicology Letters, Vol.198, 5 October, 2010, pp.134-143. doi:10.1016/j.toxlet.2010.06.011


PNIPAM nanoparticles, with and without a covalentlylinked fluorescent label, were prepared by a free radical polymerisation technique. The cytoand genotoxicity of PNIPAM nanoparticles were analysed in two representative mammalian cell lines, SW480, a colon, and HaCaT, a dermal cell line. Physical characterisation in terms of particle size and zeta potential of the PNIPAM nanoparticles was carried out both in aqueous solution and in the appropriate cell culture media. Uptake and colocalisation of fluorescently labelled PNIPAM nanoparticles was monitored in both cell lines using confocal laser scanning microscopy. Genotoxicity analysis using the Comet assay was performed in both cell lines to evaluate any DNA damage. It was observed that the PNIPAM nanoparticles were internalized and localised in lysosomes within 24 hrs. No significant cytotoxic response (p ≤ 0.05) was observed in either cell line over concentration ranges from 25 mg/l to 1000 mg/l for all exposure time periods. Furthermore, no significant genotoxic response (p ≤ 0.05) was observed in either cell line over concentration ranges from 12.5 mg/l to 800 mg/l for all exposure time periods. The results suggest that the PNIPAM nanoparticles show excellent biocompatibility in vitro.