Manufacture, detection and structural characterization of copper-chelated peptide nanoparticles, and their effect on Intestinal Porcine Epithelial Cell (IPEC-1)

To investigate the effect of copper-chelated peptide nanoparticles (P-Cu NPs) on intestinal porcine epithelial cell (IPEC-1), five common silica-based materials were used to analyze their immobilization kinetics with copper-chelated peptide (P-Cu), and the one with the highest immobilization was selected to manufacture P-Cu NPs, which were evaluated for structural characterization and stability. The cellular experiment included the control group, copper sulfate (CuSO₄) group, P-Cu group, and P-Cu NPs group. The effects of each group on oxidative stress, cell viability and absorption efficiency of IPEC-1 were observed at 12, 24, and 36 h, and concentrations of 0.5, 1, 2, 4, and 8 mg/L. The results indicated diat montmorillonite could be selected to manufacture P-Cu NPs, which had a maximum immobilization of 1.81 mg/mg and increased with decreasing pH and increasing temperature and was characterized by slow release. Moreover, IPEC-1 cells treated by P-Cu NPs had lower oxidative stress, higher cell viability and absorption efficiency than CuSO₄ and P-Cu. Therefore, P-Cu NPs as a new Cu source additive not only could improve the stability and bioavailability of P-Cu, but reduce oxidative stress, improve the cell viability and absorption efficiency of IPEC-1.