Effects of 95nm carbon black nanoparticles on inflammatory conditions in the murine lung - controversy to size dependent efficacy

Effects of nano-sized particles on sensitive population have not been well elucidated. Furthermore, their size dependency is still understudied. We have previously examined the effects of CBNP on lung inflammation related to lipopolysaccharide (LPS) or allergen in mice. This study examined the effects of pulmonary exposure to carbon black nanoparticles (95 nm: CBNP95) on these lung inflammation. In protocol 1, ICR male mice were divided into 4 experimental groups that intratracheally received a single exposure to vehicle, CBNP95 (250 g/animal), or LPS plus CBNP95. In protocol 2, ICR male mice were divided into 4 experimental groups that intratracheally received repeated exposure to vehicle, CBNP95 (100 g/animal), allergen (ovalbumin: OVA; 1 g/animal), or allergen plus CBNP95. In protocol 1, CBNP95exacerbated lung edema elicited by LPS, showing an overall trend of amplified lung expressions of proinflammatory cytokines. Furthermore, LPS plus CBNP95 significantly elevated circulatory levels of fibrinogen, macrophage chemoattractant protein-1, and keratinocyte-derived chemoattractant as compared with LPS alone. In protocol 2, CBNP95 significantly enhanced the pathophysiology of allergic asthma, characterized by eosinophilic lung inflammation. These results suggest that CBNP with size of 95nm exacerbated two types of (innate and adaptive immunity-dominant) lung inflammation. This study illustrates the need of further accumulation of evidence about dose-dependency of nanoparticles on sensitive lung diseases.