Zou Yuanwen, Wu Zhi, Huang Zhongbing, Yin Guangfu, Wang Lei, Gao Fabao
College of Materials Science and Engineering, Sichuan University, Chengdu, China.
College of Materials Science and Engineering, Sichuan University, P.O. Box: 610065, Chengdu. China.
Curr Drug Deliv. 2017;14(3):342-348. doi: 10.2174/1567201813666160223120529.
Multimodal bio-imaging is a new technique with more than one imaging modality. Eu3+ doping can tailor the multi-functions of Gd-based nanorods (NRs) to obtain the resolution the imaging at the cellular level. Silk fibroin with His and Lys can induce to fabricate metal compounds particles. However, one-step preparation of SFP-linked Eu-Gd(OH)3 NRs with cyto-compatibility is very challenging.
Eu-doped Gd(OH)3 nanorods with silk fibroin peptides (SFP-NRs) are synthesized via a simple and feasible biomimetic method in the assistance of SFPs.
The measurement results showed that these hexagonal crystal NRs possessed 300 nm of the length. Compared with pure NRs, SFP-NRs exhibited better in vitro T1 signal-enhancement of magnetic resonance (MR) imaging due to their higher ratio of Eu and Gd and SFP coating on their surface, and the longitudinal relaxivity r1 value is 2.57 (Gd mM·s)-1 under a 7.0 T MR imaging system. Furthermore, a series of in vivo T1-weighted MR images between pre- and post-injection in tumor regions for 9 h indicated that average intensity of post-injection of SF-NRs was enhanced to 68%, higher the increased value of pure NRs (19.6%), but also SFP-NRs showed the good luminescence labeling of viable cell in the fluorescence observation.
These results indicate that Eu-doped SFP-NRs have potential as T1 MR imaging contrast agents and optical imaging probe in tumor-detection field.
多模态生物成像作为一种新兴技术，融合了多种成像方式。铕（Eu3+）掺杂能够调控基于钆（Gd）的纳米棒（NRs）的多种功能，从而实现细胞水平的成像分辨率。含有组氨酸（His）和赖氨酸（Lys）的丝素蛋白可诱导制备金属化合物颗粒。然而，一步法制备具有细胞相容性的丝素蛋白肽连接的铕-氢氧化钆（Eu-Gd(OH)3）纳米棒极具挑战性。
在丝素蛋白肽（SFPs）的辅助下，通过一种简单可行的仿生方法合成了含铕的氢氧化钆纳米棒与丝素蛋白肽（SFP-NRs）。
测量结果表明，这些六方晶型的纳米棒长度为300纳米。与纯纳米棒相比，SFP-NRs由于其更高的铕和钆比例以及表面的SFP涂层，在体外磁共振（MR）成像中表现出更好的T1信号增强效果，在7.0 T MR成像系统下纵向弛豫率r1值为2.57（Gd mM·s）-1。此外，一系列肿瘤区域注射前和注射后9小时的体内T1加权MR图像显示，注射SFP-NRs后的平均强度增强至68%，高于纯纳米棒的增加值（19.6%），并且在荧光观察中SFP-NRs对活细胞也显示出良好的发光标记。
这些结果表明，掺铕的SFP-NRs在肿瘤检测领域具有作为T1 MR成像造影剂和光学成像探针的潜力。
