Surface functionalization of magnetic nanoparticles (MNPs) has been an exciting area of interest for researchers in biomedicine. In this paper, we introduce a new family of peptide dendritic ligands for functionalizing MNPs of superior quality. L-Lysine- and L-glutamic acid-based dendritic ligands with dopamine located at the focal points were fully designed and synthesized before the functionalization. Then ligands of different dendritic generations (G1 to G3) were immobilized on the surface of oleic-acid-coated hydrophobic MNPsvia ligand-exchange method to realize phase transfer. The two series of modified MNPs were systematically studied viaFTIR, TGA, XRD, TEM, DLS, VSM and zeta potential measurements. The modified MNPs exhibited an adjustable number of terminal functional groups and superior stability in aqueous solutions in a broad pH range. The surface existence of water-soluble polypeptide ligands promoted monodispersity of the particles and led to an increased hydrodynamic diameter under 30 nm from G1 to G3. After the ligand exchange process, the superparamagnetic behavior was successfully retained. The two series of modified MNPs exhibited approximate magnetization in the same generation, while the saturation magnetization of the MNPs decreased with increasing surface dendritic generation. MNPs functionalized with G1L-glutamic acid dendritic ligands had the highest saturation magnetization (55 emu g−1), which was larger than for the initial MNPs. This novel functionalization strategy provides a potential platform for designing and preparing highly stable ultrafine MNPs with high magnetization for biomedicinal applications.
磁性纳米粒子(MNPs)的表面功能化一直是
生物医学研究人员关注的一个令人兴奋的领域。在本文中,我们介绍了一种新的肽树突
配体系列,用于对质量上乘的 MNPs 进行功能化。在功能化之前,我们充分设计并合成了以
L-赖氨酸和
L-谷氨酸为基质、以
多巴胺为焦点的树突
配体。然后通过
配体交换法将不同树突代(G1 至 G3)的
配体固定在
油酸包覆的疏
水性 MNPs 表面,实现相转移。通过FFTIR、TGA、XRD、
TEM、DLS、VSM和zeta电位测量对两个系列的修饰MNPs进行了系统研究。改性后的 MNPs 具有可调节的末端官能团数量,在宽 pH 值范围的
水溶液中具有优异的稳定性。
水溶性
多肽配体的表面存在促进了颗粒的单分散性,并使 G1 到 G3 的流体力学直径增加到 30 nm 以下。
配体交换过程后,超顺磁性能得以成功保留。两个系列的修饰 MNPs 在同一代中表现出近似的磁化,而 MNPs 的饱和磁化随着表面树枝状生成的增加而降低。用 G1
L-谷氨酸树枝状
配体功能化的 MNPs 具有最高的饱和磁化率(55 emu g-1),高于初始 MNPs。这种新颖的功能化策略为设计和制备具有高磁化率的高稳定性超细 MNPs 提供了一个潜在的平台,可用于
生物医学应用。