Polyphosphate-crosslinked collagen scaffolds for hemostasis and alveolar bone regeneration after tooth extraction

Post-extraction bleeding and alveolar bone resorption are the two frequently encountered complications after tooth extraction that result in poor healing and rehabilitation difficulties.The present study covalently bonded polyphosphate onto a collagen scaffold(P-CS)by crosslinking.The P-CS demonstrated improved hemostatic property in a healthy rat model and an anticoagulant-treated rat model.This improvement is attributed to the increase in hydrophilicity,increased thrombin generation,platelet activation and stimulation of the intrinsic coagulation pathway.In addition,the P-CS promoted the in-situ bone regeneration and alveolar ridge preservation in a rat alveolar bone defect model.The promotion is attributed to enhanced osteogenic differentiation of bone marrow stromal cells.Osteogenesis was improved by both polyphosphate and blood clots.Taken together,P-CS possesses favorable hemostasis and alveolar ridge preservation capability.It may be used as an effective treatment option for post-extraction bleeding and alveolar bone loss.Statement of significance:Collagen scaffold is commonly used for the treatment of post-extraction bleeding and alveolar bone loss after tooth extraction.However,its application is hampered by insufficient hemostatic and osteoinductive property.Crosslinking polyphosphate with collagen produces a modified collagen scaffold that possesses improved hemostatic performance and augmented bone regeneration potential.