“摇铃形”金复合纳米二氧化硅在细胞和组织暗场成像中的应用

Dark field imaging of rattle-type silica nanorattles coated gold nanoparticles in vitro and in vivo

金纳米颗粒因其具有独特的物理化学及光学性质,在生物影像、癌症诊断治疗等领域表现出极大的应用前景,但因小尺寸纳米金颗粒(<20nm)在生理体液环境中稳定性较差、体内安全剂量低、被动靶向效果不明显等问题,使其在体内成像,尤其在活体肿瘤部位成像中受到较大局限.本文针对上述问题,将13nm金颗粒生长在具有特殊核壳结构的夹心二氧化硅空腔之内,形成具有新型结构的"摇铃形"金复合纳米二氧化硅(silica nanorattles@gold nanoparticles,SN@GN),既保留金纳米颗粒的强散射特性以利于细胞和动物组织中实现暗场成像,同时二氧化硅壳层将金颗粒保护起来,提高了纳米颗粒的稳定性.细胞毒性实验表明SN@GN的细胞生物相容性良好,毒性低.动物急性毒性实验表明,SN@GN的最大耐受剂量大于200mg/kg,而GN的体内最大耐受剂量仅为4.6mg/kg,显著提高了金纳米颗粒的生物相容性.本研究为SN@GN在生物暗场影像领域的应用提供了重要的实验依据.

Gold nanoparticle is a promising nanomaterial used in the field of biological imaging, cancer diagnosis and treatment. However, the research of gold nanoparticles in the dark field imaging using the light scattering characteristics is still rare and the biocompatibility has become an important problem that plagued its application. In this paper, we synthesized a novel nanostructure in which 13 nm gold nanoparticles exist in the cavity of the core-shell silica structure. This nanostructure remained gold particle dark field imaging characteristics, and improved the monodispersity and bioeompatibility of gold nanoparticles. Cytotoxicity experiments show good biocompatibility of SN@GN in vitro. Acute toxicity in mice showed that the maximum-tolerated dose of SN@GN greater than 200 mg/kg, significantly improve the biocompatibility of gold nanoparticles. This study provides an important experimental basis of SN@GN in the medical imaging application.