A comprehensive review on peptide-bearing biomaterials: From ex situ to in situ self-assembly

In the last few decades, we have witnessed the great advances of molecular self-assembly in biomedical applications. Among the building blocks for molecular self-assembly, peptide exhibits several merits such as structural designability, feasible synthetic methodology, and robust self-assembling tendency. Particularly, the excellent biocompatibility, biodegradability and bioactivity bestow peptide-based assemblies with dominant advantages as biological materials. Herein, the state-of-the-art research on peptide self-assembly is reviewed. First, we discuss the representative achievements of ex situ peptide self-assembly for cargo delivery carriers, self-deliverable nanomedicines, and tissue engineering materials, which are contributed to the prefabrication of micro/nanoarchitectures in solution. After that, the in vitro/in vivo formation of peptide-based nanomaterials is presented, which is nominated as in situ peptide self-assembly. The design principle and trigger module of in situ peptide self-assembly are summarized, with an emphasis on its biological effects used for disease imaging and therapy. Finally, the combinational modality, i.e. integrating ex situ construction of peptide self-assemblies for their delivery with in situ adaptive transformation of their morphologies to optimize outcomes, is attached, which bridges the gap between ex situ and in situ peptide self-assembly. We hope this review will provide a panoramic sketch of peptide self-assembly, which is helpful for chemists and material scientists to exploit more biomedical functions from peptide libraries for disease treatments.