Study On PH-responsive Drug Loading System Based On Mesoporous Silica

Mesoporous silica is an ideal drug carrier material,which has the characteristics of large specific surface area,large pore volume,adjustable pore size,non-toxic safety,stable structure,and easy modification.Due to its unique structure and regular distribution of pores,MCM-41 is beneficial to release drug.However,as a drug carrier,MCM-41 does not have the ability to control drug release.In this paper,tetraethylorthosilicate?TEOS?and 3-aminopropyltriethoxysilane?APTES?are co-condensed to form amino mesoporous silica?NH₂-MCM-41?,which is modified by organic reaction to obtain R-Ph-NH-MCM-41?where R:-OH,-CH₃,-COOH,-CHO?drug carriers.Through the protonation of amino groups at different pH conditions to achieve the role of drug release,the effects of different R groups on protonation conditions of amino groups are studied to further achieve the purpose of controlling drug release,aiming to prepare a good pH smart response drug Carrier.The main content of this paper includes the following aspects:?1?NH₂-MCM-41 is synthesized by co-condensation method.The results show that the amino group have been successfully grafted onto mesoporous silica.At the same time,amino group modification could improve the drug-loading performance of silica.?2?Four different drug carriers of R-Ph-NH-MCM-41?where R:-OH,-CH₃,-COOH,and-CHO?are modified by organic reactions.The results show that Me-Ph-NH-MCM-41,OHC-Ph-NH-MCM-41,HO-Ph-NH-MCM-41and HOOC-Ph-NH-MCM-41 are accumulated at pH=1.2.The drug release rates are34.63%,52.03%,43.94%,and 57.87%,respectively.At pH 7.4,the cumulative drug release is 3.21%,3.12%,3.05%,and 3.09%,respectively.Strong pH responsiveness,and almost no drug release under neutral conditions,its release behavior can be described using the Korsmeyer-Peppas kinetic model.According to drug release experiments,it can be seen that HOOC-Ph-NH-MCM-41>OHC-Ph-NH-MCM-41>HO-Ph-NH-MCM-41>Me-Ph-NH-MCM-41,R The pellet can affect the pH response of the drug carrier.