Polypyrrole/Ni(II) metal-organic frameworks nanocomposites: Fabrication, characterization, and biocompatibility investigations

Abstract

Over the past few years, possible applications of nickel nanocompounds have attracted more interest in biomedicine. This study reports the fabrication and biocompatibility of some nickel-based metal-organic frameworks (MOFs) with polypyrrole (PPy) nanocomposites, PPy/x%Ni-MOFs nanocomposites (PPy/x%Ni-MOFs, x = 20, 50, and 80), via the solution mixing procedure. The structures and chemical composition of the as-fabricated nanocomposites were investigated by FT-IR, PXRD, SEM, and TEM techniques. PPy exhibited an amorphous structure, as confirmed by the PXRD study. The spherical morphology of the pure PPy and its nanocomposites was confirmed by SEM and TEM analyses. In vitro and in vivo toxicity of the PPy/x%Ni-MOFs were assessed by MTT and hemolysis assay. The expression of inflammatory enzymes in macrophages was also evaluated by measuring the serum level of two liver transaminases. The pure PPy and Ni-MOFs were nontoxic for 3T3 fibroblasts, J774. A1 macrophages, and breast tumor MCF-7 cells. In contrast, the as-fabricated PPy/x%Ni-MOFs, especially the PPy/80%Ni-MOFs, were toxic in tumor cells (MCF-7) to a greater extent than that in the normal cells (3T3 fibroblasts, J774. A1macrophages, and human red blood cells). The PPy/80%Ni-MOFs activated macrophages to produce inflammatory enzymes COX-2 at the concentration of 75 μg mL−1. Serum level of ALT and AST, which refers to liver damage did not change significantly at 20 days post intravenous injection of PPy/x%Ni-MOFs. The as-fabricated PPy/50%Ni-MOFs demonstrated a proper degree of biocompatibility among the PPy/x%Ni-MOFs. Collectively, the as-obtained PPy/x%Ni-MOFs could be a turning point in the field of biomedicine.