Peptide-Based Biomaterials as a Promising Tool for Cancer Radiotherapy

Radiotherapy (RT) is a mainstay therapeutic strategy for cancer; however, increasing radiation damage to tumor tissues while reducing the side effects on healthy tissues remains a great challenge. To address this issue, the use of biomaterials has proven promising. Recently, attention has been paid to peptide-based biomaterials as platforms for enhancing radiotherapeutic efficacy. This review explores peptide-based biomaterial-mediated tumor RT, including radiosensitizers and radiopharmaceuticals, with the aim of introducing emerging radiosensitive methods and RT strategies using radiopharmaceuticals. The advantages of peptide-based biomaterials, including controllable synthesis, good biocompatibility, targeting functions, and self-assembly performance, are introduced. These parameters must be considered in the rational design and optimization of peptide-based RT strategies. Peptide-based radiosensitizers are generally divided into three categories: peptides as direct radiosensitizers, peptides as carriers of radiosensitizers, and targeted-peptide-modified radiosensitizers. Peptide-based radiopharmaceuticals are known as peptide-radionuclide conjugates (PRCs) and are categorized according to their peptide targets. Details of PRCs used in clinical studies and US Food and Drug Administration-approved PRCs are also presented. Finally, challenges in the clinical translation of peptide-based biomaterials as RT tools are highlighted.