Agglomeration of titanium dioxide nanoparticles increases toxicological responses in vitro and in vivo

Table 3 Summary of the in vitro (A) and in vivo (B) responses to TiO₂ exposure

(A)
In vitro responses to TiO₂ exposure
Biological endpoint	HBE		Caco2		THP-1
Biological endpoint	17 nm	117 nm	17 nm	117 nm	17 nm	117 nm
Cell metabolic activity	No	No	No	No	No	No
Cell viability	No	No	No	No	No	No
DNA damage	Yes	Yes	Yes	Yes	Yes	Yes
GSH	Yes	Yes	Yes	No	Yes	No
TEER	Yes	Yes	No	Yes	n/a	n/a
IL-8	No	No	No	No	Yes	No
IL-6	Yes	No	No	No	No	No
TNF-α	No	No	No	No	Yes	No
IL-1β	No	Yes	No	No	Yes	No
(B)
In vivo responses to TiO₂ exposure
Biological endpoint	Aspiration		Gavage
Biological endpoint	17 nm	117 nm	17 nm	117 nm
BAL cell number	No	No	n/a	n/a
BALF LDH	No	Yes	n/a	n/a
BALF proteins	No	No	n/a	n/a
BAL macrophages	No	No	n/a	n/a
BAL neutrophils	No	No	n/a	n/a
BAL lymphocytes	Yes	Yes	n/a	n/a
Blood lymphocytes	No	No	No	No
Blood monocytes	No	No	No	No
Blood granulocytes	No	No	No	No
Lung Ti	Yes	Yes	n/a	n/a
Blood Ti	No	No	No	No
BAL DNA damage	No	No	n/a	n/a
Blood DNA damage	n/a	n/a	Yes	Yes
GSH lung	No	No	n/a	n/a
GSH liver	n/a	n/a	No	No

“Yes” indicates p < 0.05 (One-way ANOVA) and a significant difference compared to control; “No” indicates p > 0.05; n/a-not available