Cellular Characterizations And Sepecific Uptake Of Luminescent Porous Silicon Nanoparticles As Nanocarriers

Porous silicon nanoparticles have been widely applied on the fields of cellular imaging,tumor imaging, biosensors, and drug delivery etc., because of its unique fluorescence properties,large surface area, high biocompatible. Based on the fabrication of porous silicon nanoparticleswith high photoluminescence and surface modification via microwave heating, we systemicallycarried out these researches of tuning photoluminescence, detecting intracellular ions,prolonging the blood circulation, and smart releasing drug molecules. The main results wereshown as followed:1. Firstly porous silicon nanoparticles had been fabricated by electrochemical etching andultrasonic dispersion. Fluorescence enhancement of porous silicon nanoparticles in ethanol ordimethylsulfoxide were observed under microwave heating. Accordingly, the mechanism wasexplored by infrared spectroscopy and scanning electron microscopy characterizations. Theresults indicated that microwave irradiation could lead to the pores enlargment and surfaceoxidation of porous silicon nanoparticles via oxidation etching. Finally, strong red fluorescencesilicon quantum dots with the size of~60nm had been successfully prepared.2. After microwave-induced hydrosilylation reaction with10-undecenoic acid, luminescentporous silicon nanoparticles showed excellent fluorescence stability under physiologicalconditions. Fluorescence quenching in as-prepared LPSiNPs was highly sensitive with theconcentration of Cu2+at μmol/L level, which could be further applied on the detection ofintracellular Cu2+.3. After microwave-induced hydrosilylation reaction with dodecene, bovine serumalbumin (BSA) was readily encapsulated onto alkyl-terminated PSiNPs surfaces viahydrophobic interaction, which could significantly improve their water-dispersibility andlong-term stability under physiological conditions. Furthermore, compared with PSiNPs alone,BSA-coated PSiNPs remarkably reduced nonspecific cellular uptake.4. As a broad-spectrum anticancer drug, doxorubicin, we found that bovine serum albuminwith an efficient loading of doxorubicin (DOX) could be readily attached ontoalkyl-terminated PSiNPs to form a novel PSiNPs-based nanocomposite with excellentlong-term stability under physiological conditions. In addition, pH-responsive release of DOXfrom these PSiNPs-based nanocomposites was clearly observed. After cellular interaction, DOXreleased from these PSiNPs-based nanocomposites were localized in intracellular nuclei, whichresulted in the enhancement of killing efficiency of cancer cells.