Polymer-protein systems have excellent characteristics, such as non-toxic, non-irritating, good water solubility and biocompatibility, which makes them very appealing as cancer therapeutics agents. Inspiringly, they can achieve sustained release and targeted delivery of drugs, greatly improving the effect of cancer therapy and reducing side effects. However, many challenges, such as reducing the toxicity of materials, protecting the activities of proteins and controlling the release of proteins, still need to be overcome. In this review, the design of hybrid polymer–protein systems, including the selection of polymers and the bonding forms of polymer–protein systems, is presented. Meanwhile, vital considerations, including reaction conditions and the release of proteins in the design process, are addressed. Then, hybrid polymer–protein systems developed in the past decades for cancer therapy, including targeted therapy, gene therapy, phototherapy, immunotherapy and vaccine therapy, are summarized. Furthermore, challenges for the hybrid polymer–protein systems in cancer therapy are exemplified, and the perspectives of the field are covered.

Atherosclerosis (AS) is an important causative agent of cardiovascular diseases, and the occurrence and development of AS is accompanied by oxidative stress, so antioxidant therapy has become one of the strategies for the treatment of AS. This study aimed to design and construct an apolipoprotein ApoA1-modified inorganic–organic composite nanosystem for AS therapy, in which ApoA1 was modified onto carboxylated CeO₂/Mn₃O₄ by covalent bonding, resulting in an inorganic–organic nanocomplex with a structure similar to that of high-density lipoprotein. The nanocomplex could effectively deliver the antioxidant nanoparticles to the AS plaque through the specific recognition between ApoA1 and the macrophage at the AS lesion site. For one thing, the nanocomplex could alleviate the oxidative stress environment of the AS site through the highly efficient antioxidant effect of CeO₂/Mn₃O₄, which played a therapeutic role in the treatment of AS. For another, it could effectively eliminate the formed lipid plaques and maximally alleviate and treat AS by utilizing the cholesterol efflux effect of ApoA1.