Bone is one of the most common metastatic sites among breast cancer (BC) patients. Once bone metastasis is developed, patients’ survival and quality of life will be significantly declined. At present, there are limited therapeutic options for BC patients with bone metastasis. Different nanotechnology-based delivery systems have been developed aiming to specifically deliver the therapeutic agents to the bone. The conjugation of targeting agents to nanoparticles can enhance the selective delivery of various payloads to the metastatic bone lesion. The current review highlights promising and emerging advanced nanotechnologies designed for targeted delivery of anticancer therapeutics, contrast agents, photodynamic and photothermal materials to the bone to achieve the goal of treatment, diagnosis, and prevention of BC bone metastasis. A better understanding of various properties of these new therapeutic approaches may open up new landscapes in medicine towards improving the quality of life and overall survival of BC patients who experience bone metastasis.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). Since the first report of COVID-19 emerging in Wuhan, China, authorities in 216 countries and territories have reported about 47.3 million COVID-19 cases and 1.2 million deaths. The WHO guidelines for the management of COVID-19 are very limited to recommendations for managing symptoms and advice on careful management of pediatric patients, pregnant women, and patients with underlying comorbidities. There is no approved treatment for COVID-19 and guidelines vary between countries. In this review, first, a brief overview is provided on the basic knowledge about the virus, clinical features of the disease, and different diagnostic methods. Then, the relationship between COVID-19, various body systems, and other complications is discussed. Finallly, different management strategies are discussed, including those drawn on computational chemistry analyses, pre-clinical investigations, and clinical trials which involve pharmacological and non-pharmacological interventions. In conclusion, despite the recent approval of different vaccine candidates, more virological characteristics of SARS-CoV-2 are required to be explored, which may result in the discovery of more potential therapeutic targets leading to safer and more effective treatment to COVID-19.