Comparison of Si Nanoparticle types for use as a Potencial Drug Delivery System for Central Nervous System Diseases

Diseases affecting the central nervous system (CNS) are considered to be some of the most debilitating conditions worldwide. The range of standard therapies for disorders affecting CNS is largely limited for many patients. Nonetheless, nanoparticle-based drug delivery offers itself to be a promising strategy for effective drug delivery into the brain, addressing the frequently arising complications with blood-brain barrier crossing. This study compared the drug adsorption ability and the surface chemistry of two types of silicon nanoparticles (Si-NPs). Si- NPs were prepared using two methods: electrochemical etching of Si wafers (Si-E) and low-pressure plasma synthesis (Si-P). Silicon nanoparticles were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and nitrogen physisorption (method of Barrett, Joyner, and Halenda (BJH) and method of Brunauer, Emmett and Teller (BET)). The size and morphology were characterized by high-resolution transmission electron microscopy (HRTEM) linked with energy-dispersive X-ray spectroscopy (EDAX) and dynamic light scattering (DLS), respectively. The concentration of the drug substance that was captured by the silicon-based drug delivery system was determined by ultra high-performance liquid-chromatography-diode-array (UHPLC-DAD) method. Results of XPS showed that the Si-E are more oxidized than Si-P. The BET analysis showed us that the Si-E have more surface area, pore volume and grain size then the Si-P, and Si-P have a bigger pore size than Si-E. We also demonstrated by XRD that silicon nanoparticles prepared by both methods have a crystalline structure. The Si-P adsorption analysis of the model compound (ferulic acid) showed better adsorption ability than Si-E. The size of the Si-P (40- 120 nm) was also measured by HRTEM.