Bioactive nanoparticles have widely been used to produce polymer nanocomposite scaffolds suitable for bone tissue engineering; however no study has investigated the effect of geometry, size, and surface properties of these nanoparticles on behavior of scaffolds. Therefore, Mehdi Sadat‐Shojai and Hassanali Moghaddas conducted this study to understand how the critical features of reinforcing nanoparticles affect the efficiency of nanocomposites. The image shows FESEM micrograph of a nanofibrous system in which poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) was combined with surface‐modified rod‐like hydroxyapatite nanoparticles. The results showed that critical properties can be controlled by incorporating appropriate amounts of nanoparticles having the specific geometry and surface properties. DOI: 10.1002/app.49810