Fe-doped 45S5 bioactive glass compositions impair the metabolic activity and proliferation of metastatic human breast cancer cellsin vitro.

Many kinds of human tumors, including breast carcinomas, frequently metastasize to the bone, making it prone to pathologic fractures. Surgical management of bone metastases ranges from the resection of metastases to bone repair. Current surgical methods for the repair of bone defects include the use of polymethyl methacrylate (PMMA)-based bone cements. A promising alternative material are bioactive glass (BG) particles that in addition to providing physical stability can also induce bone regeneration. Moreover, BGs doped with Fe₂O₃may also have a negative impact on tumor cells. Here, we tested the hypothesis that BGs can affect metastatic human breast cancer cells. To this end, we assessed the effects of different BG compositions with and without Fe₂O₃on metastatic human MDA-MB-231 breast cancer cellsin vitro. We found that all BGs tested impaired the viability and proliferation of breast cancer cells in a concentration-dependent manner. The anti-proliferative effects inversely correlated with BG particle size, and were in general less pronounced in mesenchymal stromal cells (MSCs) that served as a control. Moreover, Fe₂O₃-doped BGs were more potent inhibitors of tumor cell proliferation and metabolic activity than Fe₂O₃-free BG. Our data therefore indicate that BGs can affect human breast cancer cells more strongly than MSCs, and suggest that the presence of Fe₂O₃can potentiate anti-proliferative and anti-metabolic effects of BGs. Fe₂O₃-doped BGs thus have the potential to be used for the surgical management of metastatic bone lesions, and may in addition to their regenerative properties also allow the local control of bone metastases.