Octacalcium phosphate coating for 3D printed cranioplastic porous titanium implants

In the present study, porous three-dimensional (3D) printed titanium (Ti) implants of complex shape and predefined architecture were produced by selective laser sintering (SLS) technique. Electrochemical deposition combined with biomimetic approach was applied to low-temperature coating of these implants with metastable octacalcium phosphate (OCP) achieved via chemical transformation of dicalcium phosphate dehydrate (DCPD). X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and compressive strength analyses were applied to study the chemical composition, morphology and mechanical properties of the final OCP coating on the titanium surface. In vivo comparative study of the porous 3D printed Ti and OCP coated Ti implants has been performed using critical-size crania model, porous 3D printed Ti and coated implants were compared. A statistically significant difference in the newly formed bone thickness for OCP coated Ti implants was detected already at 6 weeks after implantation. Our results provide an experimental proof of a new concept of OCP coating for cranioplasty clinical applications.