Establishment of the newly bone regeneration therapy using polyhedra particles immobilized BMP-2 as a controlled release carrier for BMP-2

家蚕环状病毒颗粒被嵌入微米大小的多面体蛋白质晶体中，在恶劣的环境条件下可保持多年的传染性。但多面体具有显著的稳定性，可用于组织工程中细胞因子的缓释载体。在这里，我们展示了骨形态发生蛋白-2 （BMP-2）包封多面体对临界大小骨缺损的完全愈合。虽然可吸收性胶原蛋白海绵（ACS）安全有效地将重组人BMP-2 （rhBMP-2）输送到愈合组织中，但目前的治疗方案最初释放rhBMP-2的速率很高，之后速率迅速下降。BMP-2多面体浸透的ACS具有足够的成骨活性，可以促进临界尺寸骨缺损的完全愈合，但高剂量的BMP-2浸透的ACS显示骨愈合不完全，这表明含有BMP-2的多面体微晶体有望推动骨愈合的发展。

Bombyx mori cypovirus particles are embedded in micrometer-sized protein crystals called polyhedra and can remain infectious in harsh environmental conditions for years. But the remarkable stability of polyhedra can be applied on slow-release carriers of cytokines for tissue engineering. Here we show the complete healing in critical-sized bone defects by bone morphogenetic protein-2 (BMP-2) encapsulated polyhedra. Although absorbable collagen sponge (ACS) safely and effectively delivers recombinant human BMP-2 (rhBMP-2) into healing tissue, the current therapeutic regimens release rhBMP-2 at an initially high rate after which the rate declines rapidly. ACS impregnated with BMP-2 polyhedra had enough osteogenic activity to promote complete healing in critical-sized bone defects, but ACS with a high dose of rhBMP-2 showed incomplete bone healing, indicating that polyhedral microcrystals containing BMP-2 promise to advance the state of the art of bone healing.