Preparation and characterization of Sr-substituted hydroxyapatite/reduced graphene oxide 3D scaffold as drug carrier for alendronate sodium delivery

Due to the characteristics of bone metabolic microenvironment in the local area of osteoporotic bone defect, it is often difficult for ordinary bone repair materials to achieve satisfactory repair effect. In this study, a multifunctional Sr-substituted hydroxyapatite/reduced graphene oxide (Sr-HAp/RGO) 3D scaffold was fabricated by a one-step hydrothermal reduction method. Sr-HAp colloids with good dispersion stability were firstly prepared to prevent precipitation and aggregation during hydrothermal process. The Sr-HAp/RGO composite scaffold with porous structure has a high compressive strength due to the reinforcement of Sr-HAp nanoparticles. Alendronate sodium (ALN), a commonly used drug for the treatment of osteoporosis, can be effectively loaded on the Sr-HAp/RGO scaffold and released for a prolonged time. The as-prepared ALN-loaded Sr-HAp/RGO scaffold shows promising potential for osteoporotic bone defect repair.