Notably, mice treated with free Dox (group c) showed marked weight decline during the treatment, while no obvious weight variations were observed in other groups, revealing that capsulation of Dox in nanogels can effectively reduce the adverse side effects of traditional chemotherapeutic drugs (Figure ). Additionally, the major organs (heart, liver, spleen, lung, kidney, and intestine) from the mice in different groups after 14 days post intravenous injection were excised and stained with H&E for histological analysis. No evident inflammatory lesions or tissue damage appeared in any of the groups (Figure ), indicating that the assay dosage was bearable to mice and no noticeable severe side effects were caused in vivo.