Development of pH-Sensitive Alendronate-Decorated Silk Fibroin/ Alginate Nanoparticles for Active Targeting of Doxorubicin to Bone Cancers

Targeted drug delivery has a positive impact on the concentration of anticancer drugs at the tumor site and can reduce harmful side effects. In this research, silk fibroin and sodium alginate were utilized to produce nanoparticles, which were then targeted using sodium alendronate (SF-SA-ALN NPs) to improve the effectiveness of chemotherapy on osteosarcoma. The resulting nanoparticles had a surface charge of -50.5 mV and an average size of 252 nm (with PDI = 0.157). Doxorubicin (DOX) was loaded onto the nanoparticles using ionic interaction with 96% drug loading efficiency. The nanoparticles showed higher drug release at pH 5.4 compared to pH 7.4. It was also investigated the effectiveness of in vitro bone targeting using hydroxyapatite (HA) as a bone model, and found that targeted nanoparticles accumulated in HA crystals. The toxicity of the drug-loaded nanoparticles on a human osteosarcoma cell line (MG-63) revealed that the drug-targeted nanoparticles were more toxic than free drug after 24 h. This may be due to the presence of alendronate on the SF-SA-ALN NPs, which allowed for internalization of the nanoparticles through endocytosis. Overall, these nanoparticles show promise as a potential drug delivery system for osteosarcoma treatment.