Amino functionalized mesoporous silica with twisted rod-like shapes: Synthetic design, in vitro and in vivo evaluation for ibuprofen delivery

In the present study, amino functionalized mesoporous silica (Amino-MSR) with twisted rod-like shapes was successfully fabricated using biomimetic method, and employed as poorly water-soluble drug ibuprofen (IBU) carrier. The formation mechanism of silica-based carriers was elucidated by molecular docking software. As potential drug carriers for oral delivery, its application as IBU carrier was intensively investigated in vitro and vivo and compared with non-functionalized mesoporous silica nanorod (MSR). The results demonstrated that electrostatic interaction, hydrogen bonding and hydrophobic interaction played significant roles in preparing MSR and Amino-MSR, especially the electrostatic interaction between -COO- of N-myristyl- l -alanine (N-MLA) and –NH3+ of 3-aminopropyltriethoxysilane (APTES), which strongly promoted the helical packing in the process of cooperative self-assembly. After incorporating into carriers, IBU successfully transformed from crystalline state to amorphous state. Compared with MSR (22.80%), Amino-MSR showed a high drug loading content (29.12%) due to the stronger hydrogen bonding force formed between the amino enriched nano-space and carboxylic acid moiety of IBU. Consequently, both the IBU release rate and amount were significantly improved in stimulated gastric fluid (SGF) medium. Particularly, Amino-MSR exhibited controlled drug release behavior because of the stronger host-guest interaction. Benefiting from the great advantages in improving the solubility of IBU and controlled drug release behavior, IBU/Amino-MSR exhibited better anti-inflammatory effect and higher relative bioavailability (203%).