中文摘要：

将N-氨基-4-N-甲基哌嗪-1,8-萘酰亚胺（AMN）通过酰胺化反应接枝到聚丙烯酸链上,利用生成的聚合物在水溶液中的自组装,制备了一种水溶性荧光纳米粒子（PAAMN）。采用紫外可见光谱、核磁共振氢谱、透射电镜、动态光散射和荧光光谱方法对PAAMN进行了表征,MTT法检测其细胞相容性,最后用荧光显微镜观察其自身荧光及细胞成像效果。实验结果表明,PAAMN为球状结构,萘酰亚胺荧光团的摩尔取代度为4.1%;在生理pH条件下,以390 nm为激发波长,PAAMN在534 nm处发射较强的荧光,且光稳定性较好;在pH 4.0~10.0范围内,其荧光波长无明显变化,荧光强度随pH值增大而逐渐减小,但pH敏感程度小于AMN。PAAMN具有良好的细胞相容性,能进入细胞,且在~390 nm激发光下发射绿色荧光,可用于细胞成像。

英文摘要：

Polyacrylic acid was firstly grafted by N- amino-4-N- methylpiperazine-1 ,8-naphthlimide （ AMN） to prepare a amphiphilic polymer, which was self-assembled in water producing nanoparticles called as PAAMN.Then the morphology, structure and fluorescence properties of PAAMN were investigated by various methods including transmission electron microscopy, dynamic light scattering, ultraviolet-visible spectroscopy （ UV-Vis） , nuclear magnetic resonance spectroscopy （HNMR） and fluorescence spectroscopy. MTT assay was carried out to assess the cell compatibility of PAAMN. Finally, the fluorescence from PAAMN self and HeLa cells incubated with PAAMN was observed by fluorescence microscope. The results revealed that PAAMN had spherical structure, in which naphthlimide fluorphores were immobilized in the polyacrylic acid matrix with the degree of substitution of 4. 1%. Under the physiological pH condition, PAAMN excited at 390 nm could emit strong and stable fluorescence at 534 nm. In the range of pH 4.0- 10. 0, its excitation and emission wavelengths had no obvious change. The fluorescence intensity of PAAMN increased with the decrease of pH values, but the pH sensitivity of PAAMN was much lower than that of AMN. PAAMN had good cell compatibility. From the pictures of fluorescence imaging, it was found that both PAAMN self and cells-engulfed PAAMN could emit green fluorescence upon excited at 390 nm, indicating the potential of the developed nanoparticle for cell imaging.