Cytotoxicity of AuCu–Cu₂S Nanocomposites: Implications for Biological Evaluation of the Nanocomposite Effect on Bombyx mori Silkworms and Cell Lines

Abstract

AuCu–Cu2S nanocomposites are unique materials with exceptional properties that have recently received a lot of interest. However, little is known about their potential toxicity in terrestrial organisms and their subsequent effects on the environment. Therefore, it is essential to develop effective methodologies for evaluating AuCu–Cu2S nanocomposites in biological systems. This study reports the biological evaluation of the AuCu–Cu2S nanocomposite from animal and cell entity levels. The Bombyx mori silkworm was used as a model organism to study the effects of different concentrations of AuCu–Cu2S on silkworm development. Transcriptome analysis was also carried out to examine the genetic modulation exerted by the treatment. Moreover, biocompatibility and cytotoxicity of AuCu–Cu2S were evaluated in human bronchial epithelial cells 16HBE, human lung adenocarcinoma, and the insect Spodoptera frugiperda cell sf9 cell lines. The results showed that although AuCu–Cu2S at ≤400 ppm can prolong the eating habit of silkworms and promote the weight of the cocoon layer, there was an increase in silkworm mortality and a decrease in moth formation at a concentration of ≥800 ppm. The genetic regulation by AuCu–Cu2S treatment showed varying effects in the silkworm, primarily related to functions such as transport and catabolism, metabolism of cofactors and vitamins, xenobiotic biodegradation, amino acid, and carbohydrate. 16HBE, PC-9, and sf9 treated with 300 ppm of AuCu–Cu2S showed viability percentages of 60, 20, and 90%, respectively. Thus, AuCu–Cu2S at low concentrations serves as a safe and biocompatible material for the sf9 cell lines but is lethal to 16HBE and PC-9. This research could aid in understanding the biological effects and biocompatibility of AuCu–Cu2S nanocomposites, particularly in the field of biochemistry; however, the mechanisms involved need further exploration.