About this Journal Submit a Manuscript Table of Contents
BioMed Research International
Volume 2013 (2013), Article ID 539348, 10 pages
http://dx.doi.org/10.1155/2013/539348
Research Article

Vitronectin Absorbed on Nanoparticles Mediate Cell Viability/Proliferation and Uptake by 3T3 Swiss Albino Mouse Fibroblasts: In Vitro Study

1Laboratory of Applied Biotechnology, Department of Anaesthesiological, Surgical and Emergency Sciences, Second University of Napoli, Via Costantinopoli 16, 80138 Napoli, Italy
2Laboratory of Bioactive Polymeric Materials for Biomedical and Environmental Applications, UdR INSTM, Department of Chemistry and Industrial Chemistry, University of Pisa, Via Risorgimento 35, 59126 Pisa, Italy

Received 17 September 2012; Revised 5 December 2012; Accepted 6 December 2012

Academic Editor: Mandeep Singh Bakshi

Copyright © 2013 F. Rosso et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We study the interaction of 3T3 Swiss albino mouse fibroblasts with polymeric nanoparticles (NPs) and investigate cellular behaviour in terms of viability/cytotoxicity, cell cycle, NPs uptake, MAP kinase (ERK1/2), and focal adhesion kinase (FAK) activation. After incubation of NPs with cell culture media, western blot analysis showed that Vitronectin is retained by NPs, while Fibronectin is not detected. From cytotoxicity studies (MTT and BrdU methods) an LD50 of about 1.5 mg/mL results for NPs. However, NPs in the range 0.01–0.30 mg/mL are able to trigger a statistically significant increase in proliferation and cell cycle progression in dose and time depending manner. Also, biochemical evaluation of ERK1/2 and FAK clearly shows an increasing phosphorylation in a dose and time depending manner. Finally, we found by transmission electron microscopy that NPs are internalised by cells. Competitively blocking VN-integrin receptors with echistatin (1  g/mL) results in a decrease of viability/proliferation, cell cycle progression, cellular uptake, and FAK/ERK activation showing the involvement of Vitronectin receptors in signal transduction. In conclusion, our results show that cell surface NPs interactions are mediated by absorbed plasma proteins (i.e., Vitronectin) that represent an external stimuli, switched to the nucleus by FAK enzyme, which in turn modulate fibroblasts viability/proliferation.