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Heavy Metal Index

Nanoparticles skin absorption: New aspects for a safety profile evaluation

This is a review. Primary-study penetration tables (quantum dots, titanium dioxide, silver, and the metal flux table) were not re-extracted.

This is a review. Primary-study penetration tables (quantum dots, titanium dioxide, silver, and the metal flux table) were not re-extracted. Rows here are the size rules and critical sizes the authors adopt in the abstract, the discussion, and Table 7.

Key numbers

AnalyteMatrixValueUnitStatisticNWhere
nanoparticle sizeintact and damaged skin4-20nmadopted size rangep.13 (printed 319)
nanoparticle sizedamaged skin21-45nmadopted size rangep.13 (printed 319)

Methods (brief)

Literature search of PubMed, Web of Science, and Google Scholar. They separate metal and non-metal nanoparticles and propose size bands of 4 nm or smaller, 4 to 20 nm, 21 to 45 nm, and larger than 45 nm. Table 7 assigns a critical size and a hazard word to each material.

Detection and reporting: not a new assay; some cited rows in Table 6 are marked <LOD and were not extracted

Basis: particle size in physiological media

Evidence fitness

This source can support: the authors’ size-based decision tree for nanoparticle skin penetration; critical sizes they assign to Au, Ag, CdSe, silica, Co, Ni, Pd, Pt, and Rh.

It cannot support: a single dermal absorption percentage for any metal; re-use of every cited study’s concentration table as if measured in this paper.

Limitations

Withheld: Table 1 quantum-dot studies, Table 2 titanium dioxide studies, Table 5 silver studies, Table 6 donor and receiving-solution concentrations (Ag, Au, Co, Pd, Rh, Pt, including the authors’ own earlier papers), and the 2005 sunscreen formulation percentages cited from Faunce et al. No absorption fraction in percent of dose is adopted as a single number except through the qualitative penetration and permeation calls in Table 7. No NOAEL or regulatory metal limit is set.

Update history

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