. Author manuscript; available in PMC: 2016 Jan 6.

Published in final edited form as: Chem Soc Rev. 2011 Dec 14;41(6):2323–2343. doi: 10.1039/c1cs15188f

Table 4.

Effect of NPs’ shape on biological response

Particle examples	Toxicity mechanism	Physiological response	Ref.
Iron oxide, gold	Internalization and membrane disruption. Highest cellular uptake with least membrane disruption among all shapes, thus least shape dependent toxicity	Cell division dysfunction and disturbed cellular trafficking; Mechanical interference with the mitotic spindle and DNA	^204–206
SWCNT, MWCNT, TiO₂, gold, mesoporous silica	Internalization and membrane disruption. Severe influence on initiation of phagocytosis. Blockage of transport channels. Highest distorting force on cell membrane among all shapes. Smaller aspect ratios lead to faster internalization and less cell membrane disruption	Chronic inflammation due to frustrated phagocytosis, mutagenic events, mesothelioma formation	^207–213
Gold	Dependent on the average radius of curvature. Disruption of membrane integrity and transport may occur	Toxicity due to chronic inflammation or impaired phagocytosis	²⁰²
Nickel, carbon black, TiO₂	Aggregation or agglomeration changes size of particles thus increasing their visibility to macrophages	Aggregation changes retention time of particles; changes in size may increase or decrease toxicity	^{143, 214, 215}
ZnO, iron oxide	Aggregation and cell membrane disruption may be dependent on the prevalence of high aspect ratio particles	Combinational effect similar to aggregated particles and fibrous particles	^{16, 216, 217}
Quantum dots	Similar to spherical NPs	Similar to spherical NPs	²¹⁸