Daldosso N, Ghafarinazari A, Cortelletti P, Marongiu L, Donini M, Paterlini V, Bettotti P, Guider R, Froner E, Dusi S, Scarpa M
Department of Computer Science, Fluorescence Laboratory, University of Verona, Strada le Grazie 15, 37134 Verona, Italy.
J Mater Chem B. 2014 Oct 7;2(37):6345-6353. doi: 10.1039/c4tb01031k. Epub 2014 Aug 13.
Porous silicon micro-particles (micro-pSi) with size in the range of 1-10 μm are obtained by etching of silicon wafers followed by sonication. The derivatization of the micro-pSi surface by wet chemistry (silylation and coupling with a diamine) yields an interface, which exposes negative (carboxylic) or positive (amine) groups at pH 7.4. The surface modification, beyond the introduction of groups for the drug loading by covalent or electrostatic interactions, stabilizes the intense orange luminescence characteristic of the silicon nano-crystallites. Derivatization by amines introduces also a second emission in the blue region, which follows a different excitation pathway and can be attributed to the interface defects. The micro-pSi are efficiently internalized by human dendritic cells and do not show any toxic effect even at a concentration of 1 mg mL. The intrinsic luminescence of the differently functionalized micro-pSi is preserved inside the cells and permits the selective and efficient tracking of the microparticles without using molecular tags and thus leaving the organic coating available for the interaction with the drug. The results obtained suggest that the functionalized micro-pSi are an efficient platform for simultaneous imaging and delivery of therapeutic agents to the disease site.
通过对硅片进行蚀刻然后超声处理，可获得尺寸在1 - 10μm范围内的多孔硅微粒（微多孔硅）。通过湿化学方法（硅烷化以及与二胺偶联）对微多孔硅表面进行衍生化处理，可得到一种界面，该界面在pH 7.4时会暴露负性（羧基）或正性（胺基）基团。这种表面修饰除了通过共价或静电相互作用引入用于药物负载的基团外，还能稳定硅纳米晶体特有的强烈橙色发光。胺类衍生化还会在蓝色区域引入第二种发射，其遵循不同的激发途径，可归因于界面缺陷。微多孔硅能被人树突状细胞有效地内化，即使在浓度为1 mg/mL时也未显示出任何毒性作用。不同功能化的微多孔硅的固有发光在细胞内得以保留，无需使用分子标签就能对微粒进行选择性和高效追踪，从而使有机涂层可用于与药物相互作用。所获得的结果表明，功能化的微多孔硅是一个用于同时成像和将治疗剂递送至疾病部位的有效平台。
