Cytotoxicity and osteogenic effects of aluminum ions

In this study, we monitored the effect of Al³⁺ ions on mesenchymal cells (KUSA-A1) and human fibroblasts (NHDF) by means of in vitro experiments by culturing the cells with addition of small concentrations of aluminum ions (i.e., 0.1, 1, 10, and 100 ppm). Bone formation test was then conducted using KUSA-A1. Small concentrations of aluminum ions delayed but did not completely inhibit cell proliferation. The amount of bone tissue decreased as the concentration of Al³⁺ increased and crystallinity changes were also detected by Raman spectroscopic experiments. Moreover, Al³⁺ ions greatly affected both structure and chemistry of bone tissues with mineral nodules becoming larger and atomic substitution of Ca with Al in bone tissue being more preponderant with increasing Al³⁺ concentration. Such effects in turn impaired the balance between mineral and collagen in the formed bone tissue.