Facile Fabrication of Poly(L-lactic Acid)-Grafted Hydroxyapatite/Poly(lactic-co-glycolic Acid) Scaffolds by Pickering High Internal Phase Emulsion Templates

Porous scaffolds consisting of bioactive inorganic nanoparticles and biodegradable polymers have gained much interest in bone tissue engineering. We report here a facile approach to fabricating poly(l-lactic acid)-grafted hydroxyapatite (g-HAp)/poly(lactide-co-glycolide) (PLGA) nanocomposite (NC) porous scaffolds by solvent evaporation of Pickering high internal phase emulsion (HIPE) templates, where g-HAp nanoparticles act as particulate stabilizers. The resultant porous scaffolds exhibit an open and rough pore structure. The pore structure and mechanical properties of the scaffolds can be tuned readily by varying the g-HAp nanoparticle concentration and internal phase volume fraction of the emulsion templates. With increasing the g-HAp concentration or decreasing the internal phase volume fraction, the pore size and the porosity decrease, while the Young's modulus and the compressive stress enhance. Moreover, the in vitro mineralization tests show that the bioactivity of the scaffolds increases with increasing the g-HAp concentration. Furthermore, the anti-inflammatory drug ibuprofen (IBU) is loaded into the scaffolds, and the drug release studies indicate that the loaded-IBU exhibits a sustained release profile. Finally, in vitro cell culture assays prove that the scaffolds are biocompatible because of supporting adhesion, spreading, and proliferation of mouse bone mesenchymal stem cells. All the results indicate that the solvent evaporation based on Pickering HIPE templates is a promising alternative method to fabricate NC porous scaffolds for potential bone tissue engineering applications.