Efficient Drug Delivery Carrier Surface without Unwanted Adsorption Using Sulfobetaine Zwitterion

Many studies describing the high colloidal stability and antifouling effects of zwitterion nanoparticles are reported; however, to date, disadvantages including complex synthetic methods and lack of methods for hydration layer analysis persist. In this study, zwitterion nanoparticles (SiZwit) are synthesized using (3-aminopropyl)triethoxysilane and 1,3-propane sultone and the hydration layer and colloidal stability of SiZwit are analyzed. Investigation of dipole-dipole interactions between zwitterion nanoparticles and H2O molecules reveals that a stronger hydration layer is formed on the SiZwit. The antifouling effect of SiZwit increases by more than 80-90% due to the hydration layer. The colloidal stability in deionized water, phosphate-buffered saline, and in cell growth media increases more than fourfold compared to the bare silica nanoparticle (SiOH), and amine-functionalized silica nanoparticle (SiNH2). No cell cytotoxicity of SiZwit is observed and cellular uptake for normal cells and macrophages is significantly reduced. Moreover, as seen from the drug loading and release profile of SiZwit, a fourfold increase in drug loading and sustained release is observed because of stable electrostatic interactions compared to SiOH and SiNH2.