可生物降解的磁性荧光四氧化三铁/聚（DL-丙交酯-co-α，β-苹果酸）复合纳米粒用于干细胞标记。

Biodegradable magnetic-fluorescent magnetite/poly(dl-lactic acid-co-alpha,beta-malic acid) composite nanoparticles for stem cell labeling.

机构信息

Department of Diagnostic Radiology, National University of Singapore, Kent Ridge, Singapore 119260, Singapore.

出版信息

Biomaterials. 2010 May;31(13):3502-11. doi: 10.1016/j.biomaterials.2010.01.081. Epub 2010 Feb 9.

DOI:10.1016/j.biomaterials.2010.01.081

PMID:20144844

Abstract

Bifunctional superparamagnetic magnetite/poly(dl-lactic acid-co-alpha,beta-malic acid) composite nanoparticles (PLMA-MNPs) detectable by both magnetic resonance imaging (MRI) and fluorescence microscopy were synthesized by coating Fe(3)O(4) nanoparticles with biodegradable poly(dl-lactic acid-co-alpha,beta-malic acid) copolymer (PLMA) with covalently bound fluorescein isothiocyanate (FITC). The FITC modified PLMA-MNPs (FITC-PLMA-MNPs) have a hydrodynamic diameter of 100nm and an anionic surface. MTT assays of mouse macrophages, 3T3 fibroblasts and human mesenchymal stem cells (hMSCs) incubated with these nanoparticles indicated that these nanoparticles did not possess significant cytotoxicity. Furthermore, the osteogenic and adipogenic differentiations of the hMSCs were not influenced by the labeling process. As a result of the high R(2) (164.8mm(-1)s(-1)) and R(2)/R(1) ratio (32) of the FITC-PLMA-MNPs, the labeled hMSCs can be detected by a clinical 3T MRI scanner at an in vitro detection threshold of about 1200 cells. The green fluorescence associated with the FITC can be readily observed. Such nanoparticles can potentially be used as a T(2)-weighted contrast agent and fluorescent agent for stem cell labeling.

摘要

双功能超顺磁性磁铁矿/聚（DL-丙交酯-co-α，β-马来酸）复合纳米粒子（PLMA-MNPs）可通过磁共振成像（MRI）和荧光显微镜检测到，通过用可生物降解的聚（DL-丙交酯-co-α，β-马来酸）共聚物（PLMA）涂覆 Fe 3 O 4 纳米粒子来合成，该共聚物与荧光素异硫氰酸酯（FITC）共价结合。FITC 修饰的 PLMA-MNPs（FITC-PLMA-MNPs）具有 100nm 的水动力直径和阴离子表面。用这些纳米粒子孵育的小鼠巨噬细胞、3T3 成纤维细胞和人间充质干细胞（hMSCs）的 MTT 测定表明，这些纳米粒子没有表现出明显的细胞毒性。此外，hMSCs 的成骨和成脂分化不受标记过程的影响。由于 FITC-PLMA-MNPs 的高 R 2 （164.8mm -1 s -1 ）和 R 2 / R 1 比值（32），标记的 hMSCs 可以在体外检测阈值约为 1200 个细胞的情况下通过临床 3T MRI 扫描仪检测到。与 FITC 相关的绿色荧光很容易观察到。这些纳米粒子可潜在地用作 T 2 加权造影剂和荧光剂用于干细胞标记。