Comparative effects of two different aluminum nanoparticle formulations on the histological and physiological aspects of Drosophila melanogaster (Diptera: Drosophilidae) as a model

Recycling aluminum, which is widely utilized in industries such as
packaging, poses a significant challenge in selecting the most efficient
method that retains its properties while minimizing environmental impact.
This study investigates the potential adverse effects of aluminum oxide
nanoparticles (Al2O3 NPs) synthesized from disposable aluminum foil waste
using two different recycling methods: conventional grinding (CG) and ball
milling (BM). This study employs Drosophila melanogaster as a
well-established in vivo model organism to determine which recycling
technique yields nanoparticles (NPs) that are less harm to non-targets. To
assess this, relevant concentration of Al2O3 NPs formulations was added
into the food media. Seven days post feeding, alterations of adult’s
midgut were analyzed at physiological and ultrastructure levels. The
results showed that Al2O3 NPs had significant effects on digestive
enzymes, regardless of how they are synthesized. In contrast to chitinase
and protease, the activities of digestive enzymes such as lipase,
phospholipase A2, and carboxypeptidase were significantly higher in flies
exposed to Al2O3 NPs synthesized by BM than those in fed on control food
media or those supplemented with Al2O3 NPs synthesized by CG. Histological
and ultrastructural analyses revealed that both formulations of Al2O3 NPs
negatively impacted the midgut cells. However, the harmful effects were
more pronounced in NPs synthesized by the BM method compared to those
produced using the CG method. Where indistinct peritrophic membrane and
disrupted microvilli, columnar and goblet cells with numerous vacuoles
were recorded. Collectively, while the findings confirm the toxicity of
Al2O3 NPs to Drosophila, the synthesis method used to process aluminum and
convert it into nanoparticle form plays a significant role in determining
its potential hazards and should be carefully considered.