Design of injectable organic-inorganic hybrid for bone tissue repair.

Injectable bone substitutes are rapidly gained success in tissue engineering applications for their less invasive surgical aspect. Here, the design and the characterization of a novel degradable paste of PCL reinforced with nanocrystals of hydroxyapatite have been presented aiming to mimic natural tissue. Nanohydroxyapatite has been successfully synthesized via sol-gel technique. Dynamic and steady state viscoelastic properties of the solutions and paste were investigated to control the kinetic of phase transition. Correspondingly, the morphology and composition were characterized via TEM, EDAX, and thermal analysis. Injection test underlines the completely ability of the paste of being injected without altering its features. Preliminary biological study showed that the composite paste is not cytotoxic. The synergistic rheological and biological properties, combined with the positive effect of chemical synthesis method indicate that the composite paste is very suitable as local bone substitute in low-load areas.