Biphasic Peptide Amphiphile Nanomatrix Embedded with Hydroxyapatite Nanoparticles for Stimulated Osteoinductive Response The structural support and biological complexity of bone extracellular matrix (ECM) are provided within a composite microenvironment that consists of an organic fibrous network reinforced by inorganic hydroxyapatite (HA) nanoparticles. Recreating this biphasic assembly, a bone ECM analogous scaffold comprised of self-assembling peptide amphiphile nanofibers and interspersed HA nanoparticles was investigated.