Biomimetic synthesized nanoporous silica@poly(ethyleneimine)s xerogel as drug carrier: characteristics and controlled release effect.

The purpose of this study was to prepare and characterize nanoporous silica@poly(ethyleneimine)s (NS@P) xerogel and methanol modified NS@P xerogel synthesized with biomimetic method, and investigate controlled release behavior of propranolol hydrochloride (PNH) loaded carrier materials in vitro and in vivo. Preparation was conducted at ambient conditions, and NS@P xerogel as well as PNH loaded NS@P xerogel were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and differential scanning calorimeter (DSC). Investigations on morphology and porous characteristics of NS@P xerogel and methanol modified NS@P xerogel were evaluated with scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption. The results showed that the order of morphology compactness was NS@P xerogel>25%NS@P xerogel>75%NS@P xerogel because PEIs scaffold ability for silica condensation and forming hydrogen bond weakened with increasing volume ratio of methanol modification. Moreover, SBET decreased and uniformity of pore size distribution was interrupted after methanol modification. PNH loaded carrier materials displayed controlled release, and release effect was related with pore size of materials and PEIs scaffold ability. In vivo pharmacokinetic study demonstrated that release of PNH was delayed due to the PNH incorporated inside carrier materials and controlled release effect was in accordance with in vitro results.