Study On Mesoporous Fe_xSi_1-xO₂ Nanoparticles With Enhancing Transfer And Its Application In Drug Loading And Release

Mesoporous silica nanoparticles?MSNs? show significant advantages over traditional drug carriers, such as high surface area, large pore volume, uniform pore size, the easily functionalized surface and biocompatibility. These properties endow MSNs encapsulate a variety of drugs and delivere these agents to the desired location. The drug loading capacities of MSNs can be improved by altering their structures or surface functional groups. However, it's hard for the pure silica with weak acidity to form a water passage in the channel. The result of mass transfer in the process of drug delivery is seriously restricted by the water passage of MSNs. Therefore, it is important to improve the mass transfer of MSNs in the process of drug loading and release.In this study, the mesoporous Fe_xSi_1-xO₂ nanoparticles?Fe-MSNs? were fabricated by the cohydrolysis between FeCl3 and TEOS with the cetyltrimethyl ammonium bromide?CTAB? as template. Lattice defect of MSNs with Lewis acid sites were formed by Fe doped into silica lattice. The formation of Lewis acid sites of MSNs can improve the hydrophilic of micro channels and the mass tansfer was also enhanced. Compared with MSNs, the acetaminophen?AP? loading capacity of Fe-MSNs was increased from 74.29mg/g to 81.26mg/g, the AP cumulative release of Fe-MSNs was increased from 53.24% to 63.32%. These results indicate that Fe doping improved the mass transfer of Fe-MSNs channel.In order to increase hydrophobicdrug loading capacity, the surface of Fe-MSNs was functionalized with amine groups by treatment with APTS?Fe-MSNs-NH₂?. Under the best preparation conditions, the fexofenadine hydrochloride?FXD? loading efficiency of Fe-MSNs-NH₂ and Fe-MSNs was 79.32mg/g and 68.56 mg/g.In addition to the hydrophilic of channel, the pore size is also an important factor effect the diffusion mass transfer of Fe-MSNs. Under the best preparation conditions, the Fe-MSNs with different pore diameters?LMSNs? were synthesized with CTAB as the liquid crystal template and 1,3,5-trimethylbenzene?TMB? as assistant agent. Compared with Fe-MSNs, the AP loading capacity of LMSNs was increased from 81.26mg/g to 93.9mg/g, the AP cumulative release of Fe-MSNs was increased from 63.32% to 70.14%.The chemical composition and morphology of LMSNs was characterized by small angle XRD, SEM, TEM, FT-IR, and BET. The results show that LMSNs is good sphericity and the size of LMSNs is between 100 and 150 nm. The specific surface area of LMSNs is 893m2/g and the pore diameter is 4.69 nm.The drug release fitting profiles were fitted with Korsmeyer–Peppas equation and the drug release mechanism of mesoporous materials was studied.