基于维生素B12-脂质缀合物制备含钴离子的外壳交联微球负载His标签蛋白促进骨愈合的研究

复杂骨组织损伤通常会伴随相关生长因子信号的丢失，中断正常愈合模式下的蛋白质协同级联反应，进而导致骨愈合效果不佳。尽管高分子微球作为生长因子载体已被使用于骨愈合研究中，但负载能力和实用性等方面的诸多缺陷限制了其进一步的临床应用。本项目基于钴离子对重组蛋白常用的组氨酸（His）标签的高亲和性，通过合成维生素B12（钴胺素）-脂质缀合物作为表面活性剂，并结合微流控技术制备表面含钴离子的PLGA微球作为His标签蛋白载体，克服普通微球载体负载能力和实用性的缺陷。并通过基于缀合物表面活性剂脂质成分的外壳交联，该微球将具有远超普通微球载体的稳定性，可解决普通微球的初期突释的问题。该微球可作为重组蛋白的通用载体，实现在临床条件下对各类生长因子简单、灵活、快速且高效的负载，以满足骨愈合对生长因子多样化的需求。

The complex bone injury always demonstrates healing difficult because of the suspension of protein cascade reaction in normal healing mode due to the concomitant loss of relative growth factor signals. Although some polymer microspheres have been used in the clinical application as growth factor carriers, the poor loading ability and practicability limited their clinical application in bone injury healing. Based on the high affinity between cobalt ions and His-tags, this program will design a series of vitamin B12 (cobalamin)-lipid conjugate surfactants combined with microfluidic technology to prepare PLGA microspheres with cobalt ion containing surface as versatile carriers of His-tagged recombinant proteins to overcome the loading ability and practicability limitations of traditional microspheres. The shell-crosslinking based on the lipid parts of conjugate surfactants would provide microspheres of much higher stability than traditional carriers and solve the initial burst release problem of normal microspheres. These microspheres could be used as versatile recombinant protein carriers to load different His-tagged recombinant growth factors with a simple, flexible, rapid and efficient method under clinical conditions, to satisfy the requirements of diversified growth factors in the clinical complex bone injury healing.