Enhanced hemostasis and bone regeneration achieved by thrombin-simvastatin-polydopamine loaded spray-dried β-TCP/ gelatin/ soy protein isolate biocomposites in critical rat calvarial defects.

Effective bone tissue engineering strategies require scaffolds with tailored properties to address specific bone abnormalities and fractures. Herein, porous biocomposite scaffolds were fabricated via repeated freeze-casting and three-layer coating. The prepared system consisted of spray-dried β-TCP granules and bio-macromolecule gelatin-based soya protein isolate (S) combined with a layer of the biomimetic adherent poly-dopamine (PDA) for simvastatin (SIM) coating via dopamine self-polymerization through the dip-coating process. Thrombin (Th) was then loaded to make the final hemostatic hybrid bone graft (TGS/SIM/Th). The PDA adhered layer improved the mechanical qualities as expected (13.93 MPa). Additionally, MC3T3-E1 cell migration (>90%) and osteogenic differentiation (∗∗∗p < 0.001) were superior in vitro. The sustained release of SIM (∼78%) can help form new capillary networks, and the burst release of Th (∼97.2%) supports the creation of stable blood coagulation. The hemostatic time of the TGS/SIM/Th significantly decreased (∗∗∗∗p < 0.0001) in the critical-sized rat calvarial defect model and tail amputation model, which would effectively enhance the bone repair. This study shows that the fabricated biocomposite could represent a new approach for treating bone defects while absorbing a large amount of blood from onsite bleeding.