Aluminum Inhalation Reduces Silicosis in a Sheep Model

Abstract

In recent studies, we have documented that the biologic activity of quartz can be substantially reduced by surface chemistry modification with aluminum lactate treatment of the particles. In the present study, we evaluated the efficacy of aluminum lactate inhalation to reduce the biologic activity of experimental silicosis in the sheep tracheal lobe model. Four groups of 10 sheep were exposed once to either 100 ml phosphate-buffered saline (PBS) followed by aerosol inhalation of 10 ml PBS at monthly intervals (PBS-PBS group), to 100 ml PBS followed by inhalation of 100 mg aluminum lactate in 10 ml PBS (PBS-Al group), to 100 mg of quartz in 100 ml PBS followed by inhalation of 10 ml PBS (Si-PBS group), or to 100 mg of quartz in 100 ml PBS followed by inhalation of 100 mg aluminum lactate in 10 ml PBS (Si-Al group). Bronchoalveolar lavage (BAL) was repeated at monthly intervals for 6 months from before exposure (Month 0), and all sheep were autopsied at Month 6. All aerosol inhalations were carried out 24 h after BAL starting at Month 1 and monthly thereafter. In the PBS-PBS group and PBS-Al group, all BAL analyses remained at control levels and lung histology remained normal. In the Si-PBS group, BAL analyses documented significant sustained 3- to 10-fold increases in macrophages, lymphocytes, neutrophils, immunoglobulins, lactate dehydrogenase, glycosaminoglycans, lecithin, and phosphatidylglycerol, with histopathologic changes of nodular silicosis (pathologic score, 2.9 +/- 0.9) and mean retention of quartz at 2.83 +/- 0.98 micrograms/mg lung tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Organosilane-Based Coating of Quartz Species from the Traditional Ceramics Industry: Evidence of Hazard Reduction Using In Vitro and In Vivo Tests

“…Polyvinylpyridine- N -oxide (PVPNO) and aluminium salts have already been tested as non-covalent surface modifications to treat or prevent silicosis, however, with limited success (Weller, 1975; Zhao et al , 1983; Prügger et al , 1984; Bégin et al , 1986; Goldstein and Rendall, 1987; Dubois et al , 1988; Dufresne et al , 1994; Bégin et al , 1995). PVPNO forms strong hydrogen bonds via NO − groups, thus masking negatively charged SiO − groups (reviewed by Castranova, 1995), whereas aluminium lactate (AL) can block surface charges and radical formation via the aluminium cation and related ionic forces (Bégin et al , 1986; Brown et al , 1989; Duffin et al , 2001; Albrecht et al , 2004, 2007).…”

Low levels of aluminum can lead to behavioral and morphological changes associated with Alzheimer's disease and age-related neurodegeneration

“…The procedure was described as beneficial in an animal model of silicosis (Dubois et al, 1988) and continued despite the conclusion that humans suffering from silicosis, did not appreciably benefit from Al treatment (Kennedy, 1956). Harmful effects of inhaled Al, especially upon brain function, were later described (Rifat et al, 1990).…”

Crystalline Silica Particles Mediated Lung Injury

“…A couple of decades later, it was reported in the study of Denny et al 55) that inhalation of aluminum dusts can inhibit the pathogenic response of silica. The reduction in the solubility of quartz was demonstrated by a number of investigators 12,33) using aluminum powder and aluminum lactate [56][57][58][59][60] . Tetrandine: This chemical has been reported to retard and reverse the fibrotic lesions formed due to silicosis in rats 61) .…”