Kumar Rajiv, Roy Indrajit, Ohulchanskyy Tymish Y, Goswami Lalit N, Bonoiu Adela C, Bergey Earl J, Tramposch Kenneth M, Maitra Anirban, Prasad Paras N
Institute for Lasers, Photonics, and Biophotonics, University at Buffalo, State University of New York, Buffalo, New York 14260-3000, USA.
ACS Nano. 2008 Mar;2(3):449-56. doi: 10.1021/nn700370b.
In this paper we report the synthesis and characterization of organically modified silica (ORMOSIL) nanoparticles, covalently incorporating the fluorophore rhodamine-B, and surface-functionalized with a variety of active groups. The synthesized nanoparticles are of ultralow size (diameter approximately 20 nm), highly monodispersed, stable in aqueous suspension, and retain the optical properties of the incorporated fluorophore. The surface of the nanoparticles can be functionalized with a variety of active groups such as hydroxyl, thiol, amine, and carboxyl. The carboxyl groups on the surface were used to conjugate with various bioactive molecules such as transferrin, as well as monoclonal antibodies such as anti-claudin 4 and anti-mesothelin, for targeted delivery to pancreatic cancer cell lines. In vitro experiments have revealed that the cellular uptake of these bioconjugated (targeted) nanoparticles is significantly higher than that of the nonconjugated ones. The ease of surface functionalization and incorporation of a variety of biotargeting molecules, combined with their observed noncytotoxicity, makes these fluorescent ORMOSIL nanoparticles potential candidates as efficient probes for optical bioimaging, both in vitro and in vivo.
在本文中，我们报道了有机改性二氧化硅（ORMOSIL）纳米颗粒的合成与表征，该纳米颗粒共价结合了荧光团罗丹明 - B，并通过多种活性基团进行表面功能化。合成的纳米颗粒尺寸超小（直径约20纳米），高度单分散，在水悬浮液中稳定，并保留了所结合荧光团的光学性质。纳米颗粒的表面可用多种活性基团进行功能化，如羟基、硫醇、胺和羧基。表面的羧基用于与各种生物活性分子（如转铁蛋白）以及单克隆抗体（如抗claudin 4和抗间皮素）偶联，以靶向递送至胰腺癌细胞系。体外实验表明，这些生物偶联（靶向）纳米颗粒的细胞摄取量显著高于未偶联的纳米颗粒。表面功能化的简易性以及多种生物靶向分子的掺入，再加上观察到的无细胞毒性，使得这些荧光ORMOSIL纳米颗粒有可能成为体外和体内光学生物成像的高效探针。
