PAA-grafted surface and fractal feature of dense nanosilica spheres for ibuprofen delivery

Autor: Ji Hong Sun, Shi Yang Bai, Xia Wu, Qian Wang, Xiao Qi Jin
Rok vydání: 2017
Předmět:
Zdroj: Materials Chemistry and Physics. 195:213-223
ISSN: 0254-0584
DOI: 10.1016/j.matchemphys.2017.04.026
Popis: The polymer/SiO 2 hybrid material (P/SiO 2 -MPS) with core-shell structure were synthesized using the dense nanosilica spheres (DNSS) as core and pH responsive poly(acrylic acid) (PAA) as a shell. Meanwhile, using ibuprofen (IBU) as a model drug, the structure and properties of obtained P/SiO 2 -MPS were characterized by SEM, TEM, FT-IR, TGA, EDS, NMR, XRD, DLS and SAXS. The results elucidated that PAA was successfully incorporated onto the surface of DNSS, and thereafter the thickness of PAA shell could be controlled by adjusting the additive amount of AA. Particularly, SAXS patterns evidently exhibited that P/SiO 2 -MPS before IBU-loading and after releasing possessed the surface fractal feature, which increased from 2.19 for SiO 2 -MPS, to 2.41 for P/SiO 2 -MPS, to 2.54 for IBU-loaded P/SiO 2 -MPS, and to 2.65 for IBU-released P/SiO 2 -MPS. Moreover, the IBU-releasing percentage of three samples (P/SiO 2 -MPS-1, P/SiO 2 -MPS-3 and P/SiO 2 -MPS-5) increased gradually at both pH 3.0 and 7.4 with the enlarged thickness of PAA shells, while for P/SiO 2 -MPS-7 with the thickest PAA layer, its release rate was not more than that of P/SiO 2 -MPS-5. Therefore, IBU molecules were hindered from passing through PAA layer. Furthermore, the IBU loading of P/SiO 2 -MPS was fitted into the pseudo-second-order model, while its drug-release kinetic profile was favorable to Korsmeyer-Peppas model. These observations evidently demonstrated that the surface effects of P/SiO 2 -MPS on its surface fractal feature and the diffusion of IBU delivery were very important, and therefore its mechanism was essentially proposed.
Databáze: OpenAIRE
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