Nanomaterial-based drug sustainable release systems have been tentatively applied to bone regeneration. They, however, still face disadvantages of high toxicity, low biocompatibility, and low drug-load capacity. In view of the low toxicity and high biocompatibility of polymer nanomaterials and the excellent load capacity of hollow nanomaterials with high specific surface area, we evaluated the hollow polydopamine nanoparticles (HPDA NPs), in order to find an optimal system to effectively deliver the osteogenic drugs to improve treatment of bone defect. Data demonstrated that the HPDA NPs synthesized herein could efficiently load four types of osteogenic drugs and the drugs can effectively release from the HPDA NPs for a relatively longer time in vitro and in vivo with low toxicity and high biocompatibility. Results of qRT-PCR, ALP, and alizarin red S staining showed that drugs released from the HPDA NPs could promote osteogenic differentiation and proliferation of rat bone marrow mesenchymal stem cells (rBMSCs) in vitro. Image data from micro-CT and H&E staining showed that all four osteogenic drugs released from the HPDA NPs effectively promoted bone regeneration in the defect of tooth extraction fossa in vivo, especially tacrolimus. These results suggest that the HPDA NPs, the biodegradable hollow polymer nanoparticles with high drug load rate and sustainable release ability, have good prospect to treat the bone defect in future clinical practice.

基于纳米材料的药物可持续释放系统已初步应用于骨再生。然而，它们仍面临毒性大、生物相容性低和载药量低的缺点。鉴于高分子纳米材料的低毒性和高生物相容性以及具有高比表面积的中空纳米材料的优异负载能力，我们对中空聚多巴胺纳米粒子（HPDA NPs）进行了评估，以寻找有效递送成骨药物的最佳系统以改善骨缺损的治疗。数据表明，本文合成的HPDA NPs可以有效地负载四种类型的成骨药物，并且药物可以在体外和体内有效地从HPDA NPs中释放出较长的时间，具有低毒性和高生物相容性。qRT-PCR、ALP、茜素红 S 染色表明，HPDA NPs 释放的药物可以促进体外大鼠骨髓间充质干细胞 (rBMSCs) 的成骨分化和增殖。来自显微CT和H＆E染色的图像数据表明，从HPDA NPs释放的所有四种成骨药物都有效地促进了体内拔牙窝缺损的骨再生，尤其是他克莫司。这些结果表明，HPDA NPs 是一种具有高载药率和可持续释放能力的可生物降解的中空聚合物纳米粒子，在未来的临床实践中具有良好的治疗骨缺损的前景。E染色表明，HPDA NPs释放的四种成骨药物均有效促进了体内拔牙窝缺损的骨再生，尤其是他克莫司。这些结果表明，HPDA NPs 是一种具有高载药率和可持续释放能力的可生物降解的中空聚合物纳米粒子，在未来的临床实践中具有良好的治疗骨缺损的前景。E染色表明，HPDA NPs释放的四种成骨药物均有效促进了体内拔牙窝缺损的骨再生，尤其是他克莫司。这些结果表明，HPDA NPs 是一种具有高载药率和可持续释放能力的可生物降解的中空聚合物纳米粒子，在未来的临床实践中具有良好的治疗骨缺损的前景。