A Local, Sustained Delivery System for Zoledronic Acid and RANKL-Inhibitory Antibody as a Potential Treatment for Metastatic Bone Disease

Cancerous solid tumors can migrate and lead to metastatic bone disease. Drugs prescribed to reduce bone resorption from metastasis, such as zoledronic acid and the RANKL-inhibitory antibody Denosumab, cause side effects such as osteonecrosis of the jaw when delivered systemically. This project used two biocompatible materials, acrylic bone cement (PMMA) and poly(lactic-co-glycolic acid) (PLGA), to incorporate and sustain release of anti-resorptive agents. Results showed similar mechanical properties for acrylic bone cements loaded up to 6.6% drug by weight. Results showed sustained zoledronic acid release for 8 weeks from both systems, with PMMA releasing up to 22% of loaded drug and PLGA films releasing over 95%. The antibody release rate was lower, with the majority of antibody still inside the PLGA films after 8 weeks. In vitro bioactivity remained above 50% for zoledronic acid eluted from both materials at early, middle, and late time points. This study sheds light on the behavior of these biocompatible polymers at high drug weight percent loadings compared to previous studies. PLGA demonstrated superior release kinetics but inferior bioactivity of eluted drug. By incorporating anti-resorptive drugs into locally implantable materials, this work could lead to a treatment offering improved quality of life for cancer patients