Development of poly(ε-polycaprolactone)/hydroxyapatite composites for bone tissue regeneration

The incorporation of osteoconductive hydroxyapatite (HA) into poly(sigma-polycaprolactone) (PCL) may enhance the material hydrophilicity, protein adsorption, roughness, and consequently, bone formation. In this work, PCL/HA composites with 5, 10, and 25 wt% of HA were prepared by melt compounding followed by hot compression, and their properties such as torque, molecular weight, mechanical resistance, and viscosity were compared to neat PCL to understand the influence of the filler on the polymer stability and printability. The addition of 5 and 10 wt% of HA leads to properties similar to the neat PCL; therefore, these compositions were chosen to produce scaffolds by 3D printing. The scaffolds presented excellent printability and homogenous dispersion of the HA. The compressive strength modulus of both compressed samples and scaffolds is around 30 MPa, similar to cancellous bone. The presence of increasing HA content combined with surface treatment using NaOH enhanced osteoblast proliferation.