Research On The Preparation Of Electrospun Inorganic Nanofibers And The Monitoring Of Drug Release

Inorganic nanofibers doped with upconversion luminescent materials have attracted widespread attention in the field of biomedicine as carriers for drug controlled release.Nanofibers with controllable drug release and sensitive monitoring properties for drug delivery can regulate the drug release rate and obtain the real-time information between drug release amount and therapeutic effect,which are of great importance in clinical applications.Organic/inorganic hybrid precursor fibers can be readily obtained by electrospinning techniques,followed by our proposed reoxidation method to prepare flexibility-enhanced inorganic nanofibers that does not need traditional high temperature calcination.We prepared NaYF₄:Yb³⁺,Tm³⁺@SiO₂ nanofibers by reoxidation method,which can obtain stronger up-conversion luminescence compared with the traditional calcination method.More interestingly,higher drug loading capacity and slower drug releasing rate are obtained after nanofibers are modified with carboxyl.The main mechanism is ascribed to the ionic interaction between DNR molecules and carboxyl group verified by FTIR.Further experimental results show that controllable drug release can be achieved not only via this carboxyl modification,but also the change of pH.Moreover,thanks to nanofibers prepared by this reoxidation method possessing stronger luminescence,they exhibit more sensitive monitoring properties especially for monitoring trace drug release such as 1%which cannot be well monitored by nanofibers prepared by traditional calcination methods.In order to simultaneously monitor multiple drug delivery with different drug ratios,we prepared NaYF₄:Yb³⁺,Er³⁺@SiO₂ nanofibers by reoxidation method.The inorganic fiber prepared by the method has tunable multicolor upconversion fluorescence to satisfy the demand of simultaneous monitoring.By this method,the tunable green to red ratio varying from 5 to 0.3 can be achieved without changing chemical constituents or concentrations.Compared with traditional method that cannot monitor dual drug delivery and show a low sensitivity,the nanofibers prepared by our new method exhibit a high sensitivity verified by simultaneously monitoring dual drug delivery with multiple different drug ratios.Due to the tunable green to red ratio and appropriate selection criteria,these nanofibers exhibit a broad detection range of two drugs without losing excellent sensitivity,which cannot be achieved by conventional single-drug monitoring system.