Department of Oral and Maxillofacial Surgery, Kanagawa Dental College, 82 Inaoka, Yokosuka, Kanagawa 238-8580, Japan.
Sci Rep. 2012;2:935. doi: 10.1038/srep00935. Epub 2012 Dec 6.
Bombyx mori cypovirus is a major pathogen which causes significant losses in silkworm cocoon harvests because the virus 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.
家蚕质型多角体病毒是一种主要的病原体，它会导致蚕茧产量的重大损失，因为病毒颗粒嵌入到称为多角体的微米大小的蛋白质晶体中，并且可以在恶劣的环境条件下保持多年的传染性。但是多角体的惊人稳定性可以应用于细胞因子的缓释载体，用于组织工程。在这里，我们展示了通过骨形态发生蛋白 2（BMP-2）包封的多角体实现了临界大小骨缺损的完全愈合。尽管可吸收胶原海绵（ACS）安全有效地将重组人骨形态发生蛋白 2（rhBMP-2）递送到愈合组织中，但是当前的治疗方案在最初的高浓度后迅速下降，rhBMP-2 的释放速度迅速下降。负载 BMP-2 多角体的 ACS 具有足够的成骨活性，可促进临界大小骨缺损的完全愈合，但是高剂量 rhBMP-2 的 ACS 显示出不完全的骨愈合，表明含有 BMP-2 的多角体微晶体有望推进骨愈合的技术状态。
