Design of a RADA16-based self-assembling peptide nanofiber scaffold for biomedical applications.

RADA16 (RADARADARADARADA) is an amphiphilic polypeptide composed of 16 amino acids, which is composed of alternating positively charged arginine (R), hydrophobic alanine (A) and negatively charged aspartic acid (D) that repeat periodically throughout the composition. This structure allows RADA16 to form an extremely stable and highly ordered β-sheet structure by noncovalent bonding (ionic bonds, hydrogen bonds, hydrophobic action, π-π bonds, etc.). Moreover, it can form a three-dimensional (3D) nanofiber hydrogel scaffold in neutral pH with water content higher than 99% and with a physiological saline solution, having excellent biocompatibility and low immunogenicity, etc. Its degradation products are amino acids, which can reduce the possibility of an inflammatory reaction and have little effect on the normal healing process of damaged tissue. In addition, the special 3D structure of RADA16 facilitates the proliferation and differentiation of cells, making it widely used in cell culture scaffolds. Subsequent studies have found that the C-terminus or N-terminus of RADA16 is modified by a specific functional peptide, which not only retains the original function of RADA16 but also gives the RADA16 self-assembling hydrogel a more powerful function. In recent years, RADA16 and RADA16-based fusion peptides have been applied in biomedical fields, such as 3D cell culture, tissue repair, rapid hemostasis, and delivery systems, which have broad prospects. This review focuses on recent research and applications of RADA16 and RADA16-based self-assembling peptide nanofiber scaffold (SAPNS) in biomedicine.