Surface engineering using peptide amphiphiles

Synthetic nanostructures (e.g., polymers, micelles, liposomes, nanoparticles) have great utility as theranostic agents. Regarding clinical implications, synthetic biomaterials have exhibited exceptional stability as bone and dental replacements while offering a platform of nanomaterials with tunable functions allowing the facile tagging of cellular components. Bioactive dressings incorporating polymeric and inorganic composites have shown to be effective in stopping arterial bleeding. The positive aspect of decreased mortality rate because of medical advancements has unfortunately led to an increased need for technological innovations that can sustain and promote biomedical reconstruction after traumatic injuries (e.g., spinal cord injury) and diagnose and treat diseases (e.g., cancer, neurological disorders) over multiple time domains. Biomaterials developed for such applications will benefit from well-defined structures and subdomains. Peptide amphiphiles (PA) are molecular synthetic building blocks that self-assemble into multidimensional structures such as spherical liposomes and fibrous micelles with well-characterized physicochemical properties. A PA is built using a hydrophilic peptide head group and a hydrophobic lipid tail subcomponent. The development of PA-based surface-engineering systems involves two-dimensional (2D) surfaces and 3D high-aspect-ratio materials during the past few decades. We cover historical aspects of PA research, present recent examples focusing on biomedical applications, and close with a summary and future directions.