TY - JOUR

T1 - Impact of serum as a dispersion agent for in vitro and in vivo toxicological assessments of TiO2 nanoparticles

AU - Vranic, Sandra

AU - Gosens, Ilse

AU - Jacobsen, Nicklas Raun

AU - Jensen, Keld A

AU - Bokkers, Bas

AU - Kermanizadeh, Ali

AU - Stone, Vicki

AU - Baeza-Squiban, Armelle

AU - Cassee, Flemming R

AU - Tran, Lang

AU - Boland, Sonja

PY - 2017/1

Y1 - 2017/1

N2 - Nanoparticles (NP) have a tendency to agglomerate after dispersion in physiological media, which can be prevented by the addition of serum. This may however result in modification of the toxic potential of particles due to the formation of protein corona. Our study aimed to analyze the role of serum that is added to improve the dispersion of 10 nm TiO2 NPs on in vitro and in vivo effects following the exposure via the respiratory route. We characterized NP size, surface charge, sedimentation rate, the presence of protein corona and the oxidant-generating capacity after NP dispersion in the presence/absence of serum. The effect of serum on NP internalization, cytotoxicity and pro-inflammatory responses was assessed in a human pulmonary cell line, NCI-H292. Serum in the dispersion medium led to a slower sedimentation, but an enhanced cellular uptake of TiO2 NPs. Despite this greater uptake, the pro-inflammatory response in NCI-H292 cells was lower after serum supplementation (used either as a dispersant or as a cell culture additive), which may be due to a reduced intrinsic oxidative potential of TiO2 NPs. Interestingly, serum could be added 2 h after the NP treatment without affecting the pro-inflammatory response. We also determined the acute pulmonary and hepatic toxicity in vivo 24 h after intratracheal instillation of TiO2 NPs in C57BL/6N mice. The use of serum resulted in an underestimation of the local acute inflammatory response in the lung, while a systemic response on glutathione reduction remained unaffected. In conclusion, serum as a dispersion agent for TiO2 NPs can lead to an underestimation of the acute pro-inflammatory response in vitro and in vivo. To avoid potential unwanted effects of dispersants and medium components, we recommend that the protocol of NM preparation should be thoroughly tested, and reflect as close as possible realistic exposure conditions.

AB - Nanoparticles (NP) have a tendency to agglomerate after dispersion in physiological media, which can be prevented by the addition of serum. This may however result in modification of the toxic potential of particles due to the formation of protein corona. Our study aimed to analyze the role of serum that is added to improve the dispersion of 10 nm TiO2 NPs on in vitro and in vivo effects following the exposure via the respiratory route. We characterized NP size, surface charge, sedimentation rate, the presence of protein corona and the oxidant-generating capacity after NP dispersion in the presence/absence of serum. The effect of serum on NP internalization, cytotoxicity and pro-inflammatory responses was assessed in a human pulmonary cell line, NCI-H292. Serum in the dispersion medium led to a slower sedimentation, but an enhanced cellular uptake of TiO2 NPs. Despite this greater uptake, the pro-inflammatory response in NCI-H292 cells was lower after serum supplementation (used either as a dispersant or as a cell culture additive), which may be due to a reduced intrinsic oxidative potential of TiO2 NPs. Interestingly, serum could be added 2 h after the NP treatment without affecting the pro-inflammatory response. We also determined the acute pulmonary and hepatic toxicity in vivo 24 h after intratracheal instillation of TiO2 NPs in C57BL/6N mice. The use of serum resulted in an underestimation of the local acute inflammatory response in the lung, while a systemic response on glutathione reduction remained unaffected. In conclusion, serum as a dispersion agent for TiO2 NPs can lead to an underestimation of the acute pro-inflammatory response in vitro and in vivo. To avoid potential unwanted effects of dispersants and medium components, we recommend that the protocol of NM preparation should be thoroughly tested, and reflect as close as possible realistic exposure conditions.

KW - Absorption, Physiological

KW - Administration, Inhalation

KW - Animals

KW - Bronchoalveolar Lavage Fluid/chemistry

KW - Cell Line, Tumor

KW - Cell Survival/drug effects

KW - Chemical Phenomena

KW - Female

KW - Liver/drug effects

KW - Metal Nanoparticles/administration & dosage

KW - Mice, Inbred C57BL

KW - Oxidants/administration & dosage

KW - Oxidative Stress/drug effects

KW - Particle Size

KW - Pharmaceutical Vehicles/chemistry

KW - Random Allocation

KW - Respiratory Mucosa/drug effects

KW - Serum/chemistry

KW - Surface Properties

KW - Suspensions

KW - Titanium/administration & dosage

KW - Toxicity Tests, Acute

U2 - 10.1007/s00204-016-1673-3

DO - 10.1007/s00204-016-1673-3

M3 - Article

C2 - 26872950

VL - 91

SP - 353

EP - 363

JO - Archives of toxicology

JF - Archives of toxicology

SN - 0340-5761

IS - 1

ER -