The Preparation And Modification Of TiO₂ Nanotube Arrays/Mesoporous Silica Composite

Studies on local delivery system based on TiO2 nanotube arrays have attracted great attention.In order to improve the clinical applicability of TNTs,it is necessary to optimize its drug loading and release properties.In this paper,TNTs prepared by anodic oxidation had good morphology.On this basis,TNTs were modified by several methods to increase drug loading capacity while reduce the early release amount during the period of drug release,prolong the overall release time,and control the release of drugs intelligently under specific circumstances and needs.This paper mainly used hydrophilic anti-inflammatory drugs Loxoprofen sodium(LS)as drug model.Firstly,TiO2 nanotube arrays/mesoporous silica composite was prepared under the condition of weakly alkaline,using Dodecyl trimethyl ammonium bromide(DTAB)as template and tetraethyl orthosilicate(TEOS)as silicon source.During the experiment,the optimum conditions of template method were investigated,the performance of the composite was analyzed,and the drug loading and sustained release were observed and analyzed.The results showed that mesoporous silica can be successfully loaded on TNTs by template method,and the loading amount of mesoporous silica increased with the increase of soaking temperature and the prolongation of soaking time.After soaking at 35 0C for 6 h,the morphology of the composite was better.The composite had good biological activity and stability.The release behavior showed that the drug loading capacity of the sample was obviously improved through the loading of mesoporous silica,and the burst release amount in the early stage of the drug release was obviously reduced,and the sustained-release performance was greatly improved.Secondly,the amino group was grafted onto the surface of the composite by soaking the composite in AEPTMS-dimethylbenzenesolution at 50 ?.The results showed that this operation enhanced the biological activity of the composite.Under certain pH conditions,the functionalized composite carried positive charge,which will produce electrostatic adsorption with the negative charge drug Losuprofen sodium,thus increasing the amount of drug loading and optimizing the slow-release performance.Finally,the TiO2 nanotube array/mesoporous silica composite was coated with tannic acid-Fe(?)complex by a simple drip coating method.It significantly inhibited the burst release in the early stage of drug release.The coordination conditions of the complex were different under different pH conditions,which resulted in the different stability of the coating.So as to control the release of Losuprofen sodium under different pH conditions to reach pH-responsive release.The data showed that the coating of tannic acid-Fe(?)complex was not only applicable to the hydrophilic drug Losoprofen sodium,but also applicable to the hydrophobic drug Ibuprofen,and had a wide application range.