Controlled-release drug carriers based hierarchical silica microtubes templated from cellulose acetate nanofibers

We report a facile method to synthesize hollow silica microtubes (SMTs) from electrospun cellulose acetate fiber precursors. Specific surface areas of up to 765 m/g (Brunauer–Emmett–Teller) were measured for the SMTs, which had a typical wall thickness of 100 nm and submicron inner diameters. An average pore size of 4.6 nm and pore volume of 0.41 cm/g were derived from Barrett–Joyner–Halenda fitting, whereas Horvath–Kawazoe pore size distribution analysis revealed microporous median pore size and maximum pore volume of 0.7 nm and 0.18 cm/g, respectively. The as-prepared SMTs featuring microand mesoporous structures in the walls where amino-functionalized to facilitate a very high drug loading (15% by weight). Drug release profile revealed sustained release rates (79% of acetylsalicylic acid was released after 6 h). It is concluded that the high drug loading and sustained release resulted from the advantageous integration of SMTs’ hollow structure and wall mesoporosity. VC 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42562.