![]() ![]() Therefore, the aim of this study was to develop a simple, rapid, and safe method of nanoparticle dispersion using the natural lung surfactant Survanta ® for in vitro and in vivo studies. Some of these methods are laborious, time consuming, potentially toxic, and may not mimic physiological condition. Over the years, a variety of methods have been described to disperse nanoparticles, including the use of cell culture reagents, dimethyl sulfoxide, acetone, pluronic surfactant, Tween 80, and pulmonary lavage fluids. Since nanoparticles in solution tend to form coarse agglomerates in physiological media, development of methods to disperse nanoparticles is important in assessing their biological activities. These studies often rely on the use of nanoparticle preparations suspended in physiological solutions. To aid the investigations of pulmonary responses to nanoparticle exposure, several in vitro and in vivo models have been developed. In contrast, more dispersed structures can deposit in the distal alveoli, rapidly migrate into the alveolar walls, and induce interstitial fibrosis. Large agglomerates deposit in the proximal alveoli and induce granulomas. The dispersion status of single-walled carbon nanotubes (SWCNT) has been shown to influence deposition pattern as well as biological effect. Animal exposure studies have shown that a major pathologic effect of CNT exposure is pulmonary fibrosis, and that this effect is dependent on the physiochemical properties of CNT. Individual CNT have a very high aspect ratio and can agglomerate into structures which are micrometers in diameter in the dry state or upon suspension in polar and non-polar solvents. Pulmonary exposure could occur due to aerosolization of nanomaterials including agglomerates of different size and shape. Nanoparticles can come in contact with the human body through inhalation as well as ingestion and dermal deposition. As the use of CNT has become more widespread, there has been a great concern about their potential adverse effects on human health and the environment. Carbon nanotubes (CNT) are a major class of nanomaterials possessing unique mechanical, electrical, and thermal properties. Since excessive collagen production is a hallmark of lung fibrosis, the results of this study suggest that the in vitro model using lung fibroblasts may be an effective and rapid screening tool for prediction of the fibrogenic potential of SWCNT in vivo.Īdvances in nanotechnology have made possible the fabrication of materials at the nanoscale level. Similar results were observed with AD-SWCNT, supporting the conclusion that Survanta ® did not mask the bioactivities of SWCNT and thus can be used as an effective dispersing agent. SD-SWCNT stimulated collagen production of lung fibroblasts in vitro and induced lung fibrosis in vivo. ![]() The results indicate that Survanta ® was effective in dispersing SWCNT in biological media without causing cytotoxic effects at the test concentrations used in this study. Likewise, in vivo studies show that both SD-SWCNT and AD-SWCNT induced lung fibrosis in mice, whereas the dispersing agent Survanta ® alone or Survanta ®-dispersed control ultrafine carbon black had no effect. This result is supported by a similar observation using Acetone/sonication dispersed SWCNT (AD-SWCNT), suggesting that Survanta ® did not mask the bioactivity of SWCNT. Studies using cultured human lung fibroblasts show that SD-SWCNT stimulated collagen production of the cells. Non-dispersed SWCNT (ND-SWCNT) did not exhibit these effects, suggesting the importance of dispersion status of SWCNT on bioactivities. In vitro studies show that Survanta ®-dispersed SWCNT (SD-SWCNT) stimulated proliferation of lung epithelial cells at low doses (0.04-0.12 μg/ml or 0.02-0.06 μg/cm 2 exposed surface area) but had a suppressive effect at high doses. At physiologically relevant concentrations, Survanta ® produced well dispersed SWCNT without causing a cytotoxic or fibrogenic effect. The natural lung surfactant Survanta ® was used to disperse single-walled carbon nanotubes (SWCNT) in a biological medium. The aims of this study were to develop a simple and rapid method of nanoparticle dispersion using a natural lung surfactant and to evaluate the effect of dispersion status of SWCNT on cytotoxicity and fibrogenicity in vitro and in vivo. Accumulating evidence indicate that the degree of dispersion of nanoparticles has a strong influence on their biological activities. ![]()
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