Mühlfeld, Christian; Mayhew, Terry M; Gehr, Peter; Rothen-Rutishauser, Barbara
(2007).
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A novel quantitative method for analyzing the distributions of nanoparticles between different tissue and intracellular compartments.
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Journal of aerosol medicine - deposition, clearance, and effects in the lung, 20(4), pp. 395-407.
New York, N.Y.: Mary Ann Liebert
10.1089/jam.2007.0624

The penetration, translocation, and distribution of ultrafine and nanoparticles in tissues and cells are challenging issues in aerosol research. This article describes a set of novel quantitative microscopic methods for evaluating particle distributions within sectional images of tissues and cells by addressing the following questions: (1) is the observed distribution of particles between spatial compartments random? (2) Which compartments are preferentially targeted by particles? and (3) Does the observed particle distribution shift between different experimental groups? Each of these questions can be addressed by testing an appropriate null hypothesis. The methods all require observed particle distributions to be estimated by counting the number of particles associated with each defined compartment. For studying preferential labeling of compartments, the size of each of the compartments must also be estimated by counting the number of points of a randomly superimposed test grid that hit the different compartments. The latter provides information about the particle distribution that would be expected if the particles were randomly distributed, that is, the expected number of particles. From these data, we can calculate a relative deposition index (RDI) by dividing the observed number of particles by the expected number of particles. The RDI indicates whether the observed number of particles corresponds to that predicted solely by compartment size (for which RDI = 1). Within one group, the observed and expected particle distributions are compared by chi-squared analysis. The total chi-squared value indicates whether an observed distribution is random. If not, the partial chi-squared values help to identify those compartments that are preferential targets of the particles (RDI > 1). Particle distributions between different groups can be compared in a similar way by contingency table analysis. We first describe the preconditions and the way to implement these methods, then provide three worked examples, and finally discuss the advantages, pitfalls, and limitations of this method.

## Item Type: |
Journal Article (Original Article) |
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## Division/Institute: |
04 Faculty of Medicine > Pre-clinic Human Medicine > Institute of Anatomy > Topographical and Clinical Anatomy 04 Faculty of Medicine > Pre-clinic Human Medicine > Institute of Anatomy 04 Faculty of Medicine > Pre-clinic Human Medicine > BioMedical Research (DBMR) > Forschungsbereich Mu50 > Forschungsgruppe Pneumologie (Erwachsene) |

## UniBE Contributor: |
Mühlfeld, Christian; Gehr, Peter and Rothen-Rutishauser, Barbara |

## ISSN: |
0894-2684 |

## ISBN: |
18158712 |

## Publisher: |
Mary Ann Liebert |

## Language: |
English |

## Submitter: |
Factscience Import |

## Date Deposited: |
04 Oct 2013 14:55 |

## Last Modified: |
17 Mar 2015 22:02 |

## Publisher DOI: |
10.1089/jam.2007.0624 |

## PubMed ID: |
18158712 |

## Web of Science ID: |
000251992400001 |

## URI: |
https://boris.unibe.ch/id/eprint/23513 (FactScience: 42170) |