Iron Oxide-Based Nanomaterials and Mammalian Health: A Spatial Assessment of Nano Impact

Nanotechnology offers immense potential to sustain agricultural productivity while minimizing environmental impact. However, nanomaterials can exert both beneficial and adverse effects on living organisms depending on their composition, concentration, and exposure duration. The present study investigated the effects of three GYTI-awarded, patented oxalate-capped iron-based nanomaterials, iron oxide (OCIO), iron–copper oxide (OCICuox), and iron–manganese oxide (OCIMnox) on mammalian health using Wistar rats, following OECD Guideline 425. Rats were randomly assigned to treatment groups and administered OCIO, OCICuox, or OCIMnox at a dose of 2000 mg·kg−1. In parallel, rats were also fed with tomato fruits cultivated in nanomaterial-enriched soil (hereafter referred to as OCIO-treated tomato, OCICuox-treated tomato, and OCIMnox-treated tomato). The food intake and body weight of nano-exposed rats were comparable to those of the control group, with higher food consumption observed during the first week. Rats fed with OCIO-grown tomatoes exhibited a significant 1.14–1.26-fold increase in body weight, while similar growth patterns were recorded in rats administered OCICuox- and OCIMnox-grown tomatoes. Although direct OCICuox exposure caused mortality in a few rats, most animals remained healthy throughout the study. Biochemical analyses revealed that glucose levels in OCIO- and OCIMnox-administered rats were significantly elevated (p < 0.05), whereas triglyceride and cholesterol levels were reduced compared to controls. Serum creatinine and hepatoprotective enzyme (GOT, GPT) activities remained within normal ranges. Interestingly, feeding rats with OCIO- and OCIMnox-treated tomatoes markedly lowered glucose, triglyceride, and cholesterol concentrations, suggesting potential anti-diabetic and lipid-regulating benefits. Histopathological examinations of the brain, heart, liver, and lungs revealed no detrimental alterations, confirming the absence of tissue toxicity. Collectively, these findings indicate that the oxalate-capped iron-based nanomaterials (OCIO, OCIMnox, and OCICuox) are nontoxic and biocompatible, demonstrating their suitability for agricultural and other biological applications with minimal adverse impact on mammalian health.