Kinetics of silica nanoparticles in the human placenta

Abstract

The potential medical applications of nanoparticles (NPs) warrant their investigation in terms of biodistribution and safety during pregnancy. The transport of silica NPs across the placenta was investigated using two models of maternal–foetal transfer in human placenta, namely, the BeWo b30 choriocarcinoma cell line and the ex vivo perfused human placenta. Nanotoxicity in BeWo cells was examined by the MTT assay which demonstrated decreased cell viability at concentrations >100 µg/mL. In the placental perfusion experiments, antipyrine crossed the placenta rapidly, with a foetal:maternal ratio of 0.97 ± 0.10 after 2 h. In contrast, the percentage of silica NPs reaching the foetal perfusate after 6 h was limited to 4.2 ± 4.9% and 4.6 ± 2.4% for 25 and 50 nm NPs, respectively. The transport of silica NPs across the BeWo cells was also limited, with an apparent permeability of only 1.54 × 10⁻⁶ ± 1.56 × 10⁻⁶ cm/s. Using confocal microscopy, there was visual confirmation of particle accumulation in both BeWo cells and in perfused placental tissue. Despite the low transfer of silica NPs to the foetal compartment, questions regarding biocompatibility could limit the application of unmodified silica NPs in biomedical imaging or therapy.

• transport
• BeWo cells
• placental perfusion
• nanotoxicology
• in vitro

Acknowledgements

The authors are grateful for the support of Maria Dusinska, Lucienne Juillerat, Margaret Saunders and Antonio Marcomini in their leadership roles within the NanoTEST Consortium. The Core Facility for Integrated Microscopy (http://www.cfim.ku.dk) is acknowledged for support with confocal microscopy.

Declaration of interest

The authors report no conflicts of interest in this work. The authors acknowledge funding provided through the NanoTEST Consortium, supported by the European Commission FP7 (Health-2007-2001.3-4, contract number 201335). M. S. Poulsen is supported by the Institute of Public Health, Copenhagen University. E. Rytting is supported by a research career development award (K12HD052023: Building Interdisciplinary Research Careers in Women's Health Program, BIRCWH) from the National Institute of Allergy and Infectious Diseases (NIAID), the NICHD and the Office of the Director (OD), National Institutes of Health (NIH). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIAID, NICHD, OD or the NIH.