A comparison of poly(methyl methacrylate) and silorane-based cements as carriers for local doxorubicin delivery

Orthopedic osteosarcomas and metastatic lesions can be difficult to treat with systemically delivered chemotherapy agents alone. Following removal of the primary tumor, implantation of cement to fill the lesion is often done to stabilize weight-bearing bones. One of the commonly used treatments to address osteosarcoma is systemic delivery of doxorubicin. Therefore, research on the incorporation and release of efficacious doxorubicin for local delivery from cement is important. Poly(methyl methacrylate) (PMMA)-based bone cements are the gold standard in orthopedics but have inherent disadvantages. Efforts to overcome some of these deficiencies led to the development of a novel silorane-based biomaterial (SBB). This work evaluated the ability of both PMMA and SBB to incorporate and release efficacious doxorubicin. PMMA-released doxorubicin showed reduced chemotherapeutic efficacy in vitro. The mechanical properties of PMMA were reduced from controls upon doxorubicin incorporation, likely stemming from doxorubicin inhibition of PMMA radical polymerization. SBB properties were not affected by doxorubicin incorporation and SBB eluted doxorubicin was fully efficacious in vitro compared to doxorubicin controls. These results indicate a likely inhibitory interaction between PMMA and doxorubicin, which affects both the strength of PMMA and the efficacy of doxorubicin. Further, this work illustrates SBB as a potential biomaterial alternative for traditional acrylics for medical biomaterial applications where load-bearing strength alongside drug delivery are key factors.