Fractal evolution of dual pH- and temperature-responsive P(NIPAM- co-AA)@BMMs with bimodal mesoporous silica core and coated-copolymer shell during drug delivery procedure via SAXS characterization

The dual (pH- and temperature-) responsive core-shell structured mesoporous nanomaterial P@BMMs were prepared using bimodal mesoporous silica as a core and poly(N-isopropyla crylamide-co-acrylic acid) P(NIPAM-co-AA) copolymer as a shell. Ibuprofen (IBU) was used as a model drug, and the effects of copolymer-coated shell thickness on drug loading and controlled release behavior were investigated by means of N-2 sorption isotherms, dynamic light scattering measurements, X-ray diffraction patterns, Fourier transform infrared spectra, scanning electron and transmission electron microscopy, thermogravimetric profiles, and elemental analysis techniques. Particularly, their fractal evolutions in the drug delivery durations were explored via small angle X-ray scattering methods, demonstrating that the resultant P@BMMs before IBU-loading and after releasing possess the typical fractal features with spherical morphology. Meanwhile, the estimation for shell thickness of P@BMMs coating in different time intervals indicated that the drug-loaded capacity was improved with the increasing shell thickness, but drug-released rate varies, strongly depending on both shell thickness and release conditions. The drug delivery mechanism was preliminarily explored, following the Korsmeyer-Peppas model. Finally, cytotoxicity in cell and pharmacokinetic of released-IBU from hybrid nanocomposite in mice via intravenously injection were preliminarily explored. (C) 2019 Production and hosting by Elsevier B.V. on behalf of King Saud University.