用磁性颗粒标记细胞进行活体检测在生物医学应用方面是一个很吸引人的领域。构建同时具有荧光和磁性的纳米结构有利于在体的疾病诊断，实现实时在线示踪活细胞。我们选用壳聚糖(CS)作为包覆材料，合成了一种简单、稳定的双功能纳米探针，它同时具有荧光和磁学性能。壳聚糖具有天然，生物相容性好，无抗原性，易降解等优点。FITC的异硫氰酸根与壳聚糖的氨基结合得到具有荧光性质的改性壳聚糖(FITC-CS)，然后修饰磁性纳米颗粒（γ-Fe2O3），经通过流式细胞术、细胞磁共振成像、荧光显微镜等手段证明这种FITC-CS磁性纳米探针能够高效的标记癌细胞。在细胞数量为1×104 时，T2*信号强度明显降低。细胞毒性试验证明这种探针有良好的生物相容性，符合生物医学应用的要求。
Fig.1. Schematic diagram of preparation of FITC-CS@MNPs
Fig.2. T2* imaging of different number cells when labeled with FITC-CS@MNPs in vitro. Cells ranging from 5×102 to 1×105 after treatment with 15.44µg FITC-CS@MNP for 2h were scanned. Unlabeled cells of identical numbers and distilled water were scanned as a control group.
Fig.3. Fluorescent image of SMMC-7721 cells when incubation with (a) Control; (b) (c) FITS-CS@MNPs for 8h.
Yuqing Ge, Yu Zhang, Shiying He, Fang Nie, Gaojun Teng, Ning Gu. Fluorescence modified chitosan-coated magnetic nanoparticles for high-efficient cellular imaging, Nanoscale Research Letters. Volume 4, Issue4 (2009), Page 287.
