Renal clearable BiOI nanodots with M1 macrophage membrane coating for enhanced radiotherapy of hepatocellular carcinoma

•Ultrasmall BiOI nanodots with M1 macrophage membrane coating were developed to enhance the efficacy of radiotherapy against hepatocellular carcinoma.•BiOI@M possessed an excellent capability to act as a radiosensitizer and showed rapid renal clearance and low systemic toxicity.•BiOI@M exhibited prolonged circulation time inside the body and good tumor targeting.•The enhanced radiotherapeutic effects of BiOI@M significantly inhibited tumor growth, thus providing an innovative avenue for the treatment of hepatocellular carcinoma.