Peptide amphiphiles (PAs) are a class of molecules that combine the structural features of amphiphilic surfactants with the functions of bioactive peptides. They self-assemble into one-dimensional (1D) nanostructures, primarily nanofibers, under physiological conditions. These nanostructures are highly bioactive and have significant potential in biomedical applications such as tissue engineering, regenerative medicine, and drug delivery. This review highlights strategies for using molecular self-assembly to produce PA nanostructures and materials, and efforts to translate this technology into therapeutic applications. Recent progress in using these materials for spinal cord injury treatment, angiogenesis induction, and hard tissue regeneration and replacement is also discussed. PAs consist of a hydrophobic domain, a short peptide sequence capable of forming intermolecular hydrogen bonds, charged amino acids for solubility and pH/salt responsiveness, and bioactive signals for cell interaction. The self-assembly of PAs is driven by hydrophobic interactions, hydrogen bonding, and electrostatic repulsions. The resulting nanostructures can be tailored for specific functions, such as drug delivery, cell signaling, and tissue regeneration. The internal packing of PA nanofibers influences their morphological and functional properties, including their ability to present bioactive epitopes. Strategies to control PA self-assembly include modifying molecular forces, varying assembly environments, and introducing co-assembling molecules. These strategies allow for the creation of nanofibers with controlled shapes, sizes, and surface chemistries. PAs can be used to encapsulate small molecules, such as hydrophobic drugs, and to functionalize carbon nanotubes. Cross-linking chemistries enhance the robustness of PA nanofibers, while surface patterning enables the creation of bioactive surfaces for cell adhesion and tissue engineering. PA nanofibers have been used in regenerative medicine for neural regeneration, hard tissue replacement, and angiogenesis. They can support cell growth, promote differentiation, and provide structural support. The ability to tune the gelation time of PA nanofiber networks allows for the development of injectable biomaterials. PAs have also been used to enhance the bioactivity of traditional tissue engineering materials, such as poly(glycolic acid), by functionalizing their surfaces with bioactive epitopes. In summary, PA nanofibers offer a versatile platform for the development of bioactive materials with applications in regenerative medicine, drug delivery, and tissue engineering. Their ability to self-assemble into controlled nanostructures, combined with their tunable properties, makes them a promising tool for biomedical applications.Peptide amphiphiles (PAs) are a class of molecules that combine the structural features of amphiphilic surfactants with the functions of bioactive peptides. They self-assemble into one-dimensional (1D) nanostructures, primarily nanofibers, under physiological conditions. These nanostructures are highly bioactive and have significant potential in biomedical applications such as tissue engineering, regenerative medicine, and drug delivery. This review highlights strategies for using molecular self-assembly to produce PA nanostructures and materials, and efforts to translate this technology into therapeutic applications. Recent progress in using these materials for spinal cord injury treatment, angiogenesis induction, and hard tissue regeneration and replacement is also discussed. PAs consist of a hydrophobic domain, a short peptide sequence capable of forming intermolecular hydrogen bonds, charged amino acids for solubility and pH/salt responsiveness, and bioactive signals for cell interaction. The self-assembly of PAs is driven by hydrophobic interactions, hydrogen bonding, and electrostatic repulsions. The resulting nanostructures can be tailored for specific functions, such as drug delivery, cell signaling, and tissue regeneration. The internal packing of PA nanofibers influences their morphological and functional properties, including their ability to present bioactive epitopes. Strategies to control PA self-assembly include modifying molecular forces, varying assembly environments, and introducing co-assembling molecules. These strategies allow for the creation of nanofibers with controlled shapes, sizes, and surface chemistries. PAs can be used to encapsulate small molecules, such as hydrophobic drugs, and to functionalize carbon nanotubes. Cross-linking chemistries enhance the robustness of PA nanofibers, while surface patterning enables the creation of bioactive surfaces for cell adhesion and tissue engineering. PA nanofibers have been used in regenerative medicine for neural regeneration, hard tissue replacement, and angiogenesis. They can support cell growth, promote differentiation, and provide structural support. The ability to tune the gelation time of PA nanofiber networks allows for the development of injectable biomaterials. PAs have also been used to enhance the bioactivity of traditional tissue engineering materials, such as poly(glycolic acid), by functionalizing their surfaces with bioactive epitopes. In summary, PA nanofibers offer a versatile platform for the development of bioactive materials with applications in regenerative medicine, drug delivery, and tissue engineering. Their ability to self-assemble into controlled nanostructures, combined with their tunable properties, makes them a promising tool for biomedical applications.