Research On Preparation Of Hollow Mesoporous SiO₂ Nanoparticles As Drug Carriers And Nanochannel Encapsulating Technology

As a new type of drug carriers,hollow mesoporous silica micro/nanoparticles has large specific surface area,good biocompatibility.and large amount of drug molecules can be loaded based on its unique hollow structure.However,due to connectivity of the nanopores,it is hard to realize complete encapsulation because of molecular thermal movement and steric effect of surface functional groups.As a result,drug molecule would be released in the process of transportation.It will not only cause toxic side effects for healthy tissue and organs,but also reduce efficiency of target drug delivery.Hence,there is a need for a highly efficient nanopores encapsulating technology,which can realize the reliability of drug molecule encapsulation and make full use of hollow structure to realize ultra-high drug loading.In this work,we designed and prepared hollow mesoporous silica micro/nanoparticles and coated a layer of ultra-thin Al2O3 on the surface.We also built the p H responsive drug delivery system,which is based on a controllable degradation of the Al2O3 coating layer.We used emulsion method to synthesize polystyrene template particles.By adding a certain amount of surfactant and silica precursor,we successfully prepared HMSNPs of different size.The morphology,structure and dispersibility were characterized by scanning electron microscope(SEM),transmission electron microscope(TEM)and Brunauer-Emmett-Teller(BET)measurement.At the same time,complete encapsulation can be realized by the growth of a nano layer(Al2O3)on the surface of HMSNPs.Under the condition of acidic tumor microenvironment,the encapsulation layer would auto-degraded to realize the controlled release.In this paper,we investigated the loading capacity and p H-controlled release of different drug molecule,including rhodamine B,crystal violet,malachite green,sunset yellow and doxorubicin.In summary,this project proposed a complete encapsulation technology to realize ultra-high drug loading and stimulus response and release,thereby further improve the delivery efficiency of anti-cancer drugs.We hope that this technology can be used in clinical medicine,as well as provide a new type and highly efficient drug carrier.