Boosting Cancer Therapy with Bacteria and Metal

Radiotherapy, a common cancer treatment, often struggles to effectively kill tumor cells. Researchers have discovered a unique way to enhance this therapy using a clever combination of bacteria and a metal called selenium. They've created tiny particles, called BL@SeNPs, which are made by coating the probiotic bacterium Bifidobacterium longum (BL) with selenium nanoparticles (SeNPs). These BL@SeNPs have a special ability to target the oxygen-deprived areas of tumors, which are known as hypoxic regions. Once they reach these areas, they stick to the tumor cells and prevent them from multiplying. The selenium in the nanoparticles also generates reactive oxygen species (ROS), which can damage the tumor cells' DNA and stop their growth. This damage leads to a type of cell death that triggers the immune system to fight the tumor. In addition to directly attacking tumor cells, BL@SeNPs can also act as a trigger for immune cells. They activate dendritic cells, which are important for initiating immune responses. Moreover, when combined with radiotherapy, BL@SeNPs reduce the number of immunosuppressive cells within tumors, such as tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), and tumor-associated neutrophils (TANs). This change in the tumor microenvironment makes it harder for tumors to grow and spread. This innovative approach offers a promising new strategy for cancer treatment. It not only makes radiotherapy more effective but also helps the immune system fight the tumor. This study highlights the potential of using biomimetic nanoparticles to improve cancer therapies and paves the way for developing even more advanced nanoradiosensitizers in the future.