Catalase-positive Staphylococcus epidermidis based cryo-millineedle platform facilitates the photo-immunotherapy against colorectal cancer via hypoxia improvement

The synergistic anti-tumor impact of phototherapy and a cascading immune response are profoundly limited by hypoxia and a weakened immune response. Intravenous and intratumoral injection of therapeutic drugs also cause pain, rapid drug clearance and low utilization rates. Here, a novel cryo-millineedle platform for intratumoral delivery of a phototherapy system, S.epi@IR820, is developed in this work, combining the properties of Staphylococcus epidermidis (S. epidermidis) and IR820 for photo-immunotherapy of colorectal cancer. In this cryo-millineedle platform, S. epidermidis enhances the near-infrared absorption and light stability of IR820 and catalyzes the decomposition of H