Emerging Nanocarrier Strategies for Optimized Drug Delivery in the Treatment of Primary Bone Cancer.

Primary bone cancer is a relatively rare malignant tumor that manifests in the bone and affects the normal functioning of the bone tissue. Primary bone cancer can be characterized into three subtypes, which are osteosarcoma, chondrosarcoma, and Ewing sarcoma. Notably, the treatment of primary bone cancer with conventional modalities, like chemotherapy and surgical interventions, has been overwhelmed with dismal clinical outcomes. The conventional therapies are challenged with non-specificity, resulting in off-target effects and ultimate harm to healthy tissue. Particularly, chemotherapy as a first-line treatment option is riddled with poor drug bioavailability, limited tumor accumulation, and increasing drug resistance. Several innovative drug delivery systems, including nano-based carriers, have been investigated to overcome the systemic drug delivery challenges in primary bone cancer. Accordingly, with most reviews focusing on bone metastasis (secondary bone cancer), this current narrative review aims to provides critical insights on nanocarrier strategies for drug delivery in primary bone cancer, comprehensively expounding on the epidemiology, cellular mechanisms, and etiological effects of primary bone cancer, as well as the current therapies and new drug nanocarriers prototyped to optimize the clinical outcomes in bone cancer management.