ALB and neoplasm: Cai et al. hybridized human serum albumin with hemoglobin through intermolecular disulfide bonds to develop a Ce6 coated mixed protein- O2 nano-capsules (C@HPOC) for O2 self-contained PDT, which realized tumor targeted co-delivery of photosensitizer and O2, and significantly alleviated tumor hypoxia (Figures 4A, B) (Chen et al., 2018).