Inhalation of Bacterial Cellulose Nanofibers Facilitates Silica Particle Clearance in a Rat Silicosis Model

Abstract

Background: Millions of workers globally are afflicted by pneumoconiosis, a disease caused by inhaling dust or particles. A particularly prevalent form is silicosis, caused by inhaling silica particles. The Chinese herbal medicine kombucha, which contains Gluconacetobacter xylinus and yeasts, can effectively clear dust from rats’ lungs. The study presented here assessed the potential effectiveness of inhalable bacterial cellulose nanofibers (IBCNs) prepared from G. xylinus cultures for facilitating clearance of silica particles in a rat silicosis model. Methods: For this purpose, 50 mg portions of silica dust were injected into lungs of rats, which were subsequently exposed to IBCNs for a month. The treatment’s effects were then evaluated by examining the extent and severity of histopathological lesions in the animals’ lungs, analyzing gas contents of blood samples, and determining organ coefficients, lung collagen contents, lungs’ dry and wet weights, silica particle clearance rates, and both numbers and types of cells in lung lavage fluid. Results: IBCN inhalation was found to relieve the detrimental effects of silica exposure and facilitated silica particle clearance in a rat silicosis model. Unexpectedly, our results also indicated that saline inhalation also strongly stimulates silica particle clearance from rat lungs. Conclusions: These results provide the first evidence for a functional effect of IBCN inhalation in a rat silicosis model, indicating that bacterial cellulose nanofiber inhalation can facilitate silica particle clearance. Further studies are required to determine whether these effects are mediated by IBCN and define the mechanisms involved. The findings also indicate that salt water may effectively clear dust from lungs, thereby alleviating risks of silicosis and reducing risks associated with haze and smog.