writer：Lijie Dong, Shuhua Liu, Haitao Gao, Ning Ding, Wolfgang Tremel, Chuanxi Xiong, Wolfgang Knoll
keywords：biological activity，drug delivery，magnetic materials，nanoparticles，self-assembly
source：期刊
Issue time：2009年

  In this work, surface-adsorbed gelatin polypeptide chains ensure the biocompatibility. Briefly, uniform 100- nm FeCo/gelatin nanospheres are assembled from in situ formed small primary FeCo NCs with the aid of gelatin polypeptides. During the assembly, the small primary FeCo NCs are encapsulated by gelatin chains through the multidentate coordination mode, followed by orderly assembly into bigger nanospheres at elevated temperature (220 ^oC), and finally uniform megranate-like nanospheres are formed and further stabilized by gelatin polypeptide shell. Because of the outer-surface gelatin polypeptide shells, the FeCo/gelatin nanospheres exhibit excellent dispersibility and can provide fine colloids in aqueous solution and buffers. More importantly, the self-assembled nanospheres show high capacity of loading DNA in PBS buffer. We demonstrated the maximum loading capacity of DNA can reach as high as 65mg/mg, which is higher than the highest value reported so far (50 mg/mg) for mesoporous silica-encapsulated magnetic nanoparticles. Similarly important is that the DNA releasing efficiency is up to 92%, which holds great promise for practical DNA therapeutical applications.