Porous poly(L-lactic acid) scaffold reinforced by titanium dioxide nanoparticles

Particle reinforcement is one kind of modification method to improve the physical and chemical properties of polyester-based biodegradable polymers. We build titanium dioxide (TiO₂) nanoparticle reinforced poly(L-lactic acid) (PLLA/TiO₂) porous scaffolds using thermally induced phase separation (TIPS) and further examine the influence of TiO₂ contents on the physicochemical properties of porous scaffolds. With improving the doses of TiO₂ nanoparticles from 0 to 2%, the compressive strength and modulus of the scaffolds increase from 1.15 to 1.49 MPa and from 22.3 to 30.5 MPa, respectively, whereas the porosities decrease from 82.0 to 70.3% despite the scaffolds still can keep their porous structure. During in vitro hydrolytic degradation for 20 weeks, the scaffolds begin to fracture and the porous structures turn irregular, which become obvious with increasing the contents of TiO₂. These results prove that the introduction of TiO₂ nanoparticle can accelerate the degradation of PLLA matrix. The present finding demonstrates the potential of PLLA/TiO₂ porous scaffold in tissue regeneration.