Paper Title
Release of 5-Fluorouracil in Acidic Medium by 2-Vinylpyridine-Capped Mesoporous Silica Nanoparticles

Abstract
Ever since the encounter of ordered mesoporous silica materials in early 90’s, synthesis and applications of mesoporous solids have received increasing attention due to their high surface area, highly ordered structures, and larger pore sizes. Over the past few decades, mesoporous silica nanoparticles (MSN) have been advancing as pharmaceutical drugs delivery system by adsorption and release test of various anti-cancer drugs. Although MSN possessed great possibilities as drug delivery vehicle, its cell targeting specificity is still a question to be answered. Thus, the purpose of this study is to explore the potential of MSN to be functionalized based on stimuli such as pH by using 2-vinylpyridine (2-VP) as the acidic pH responsive material, as the cancerous cell is more acidic than the normal cell, it will assist the material to release drugs to more specific target. MSN was synthesized by sol gel method and further used to adsorb the 5-fluorouracil (5-FU) as the model drug. The addition of 2-VP was conducted after the adsorption of 5-FU. It was found that in pH 5, the initial release rate of 5-FU from MSN was significant, which was 0.37 mg/min, compared to almost no release of 5-FU in pH 7, which indicated that 2-VP partially exist in protonated form in acidic condition, which promote the breaking of 5-FU bond with MSN, which subsequently formed the release path for 5-FU form MSN channel. Keywords - Mesoporous silica nanoparticles; Drug delivery; Adsorption; Fluorouracil; 2-vinylpyridine