Fine-tuning the release of molecular guests from mesoporous silicas by controlling the orientation and mobility of surface phenyl substituents [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 546 Inorganic chemistry
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2017
• Mô tả vật lý: Size: p. 73-80 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 260315
• Chủ đề: 1. 37 inorganic, organic, physical, and analytical chemistry; 2. 60 applied life sciences; 3. Controlled release; 4. Drug delivery systems; 5. Ibuprofen; 6. Interface; 7. Mesoporous silica nanoparticles; 8. Polarity

Tóm tắt

Phenyl-functionalized mesoporous silica materials were used to explore the effect of non-covalent interactions on the release of Ibuprofen into simulated body fluid. Variations in orientation and conformational mobility of the surface phenyl groups were introduced by selecting different structural precursors: a rigid upright orientation was obtained using phenyl groups directly bound to surface Si atoms (Ph-MSN), mobile groups were produced by using ethylene linkers to connect phenyl groups to the surface (PhEt-MSN), and groups co-planar to the surface were obtained by synthesizing a phenylene-bridged periodic mesoporous organosilica (Ph-PMO). The Ibuprofen release profiles from these materials and non-functionalized mesoporous silica nanoparticles (MSN) were analyzed using an adsorption-diffusion model. The model provided kinetic and thermodynamic parameters that evidenced fundamental differences in drug-surface interactions between the materials. All phenyl-bearing materials show lower Ibuprofen initial release rates than bare MSN. The conformationally locked Ph-MSN and Ph-PMO have stronger interactions with the drug (negative ?G of adsorption) than the flexible PhEt-MSN and bare MSN (positive ?G of adsorption). These differences in strength of adsorption are consistent with differences between interaction geometries obtained from DFT calculations. B3LYP-D3-optimized models show that ?-? interactions contribute more to drug adsorption than H-bonding with silanol groups. Here, the results suggest that the type and geometry of interactions control the kinetics and extent of drug release, and should therefore serve as a guide to design new drug delivery systems with precise release behaviors customized to any desired target.