Preparation And Application Of AIEgens-functionalised Inorganic-organic Hybrid Materials

In recent years,the combination of diagnostic probes and therapeutic agents in a carrier for cancer therapy has become a hot research topic in biomedicine.A more intelligent and versatile diagnostic nanosystem is desired in the complex in vivo physiological environment to achieve the desired diagnostic and therapeutic effects.Fluorescence technology has been widely used in imaging-guided cancer therapy due to its sensitivity,non-radioactive character,and easy operation.However,conventional fluorescent agents have a high fluorescence quantum efficiency in dilute solutions,but the fluorescence becomes weak or even quenched when they are aggregated or immobilized on solid materials,named the ACQ effect,which largely limited the applications of these fluorescent materials.Unlike ACQ effect,AIE effect is a novel unique luminescence phenomenon.Chromophores with AIE character do not emit light in dilute solutions,but emit strong fluorescence in a solid state.AIE effect breaks through the limitations of ACQ effect and is widely used in chemicals sensing,OLED,and bioimaging,which is of great importance in reality.Inorganic mesoporous materials have the advantages of large specific surface area,abundant mesopores,adjustable morphology,easy surface functionalization and good biocompatibility,can be used as an ideal drug delivery system.Therefore,preparing AIEgens-functionalised inorganic organic hybrid materials which combines the advantages of both AIE luminogens and mesoporous materials with excellent luminescence property to obtain effective drug release systems for imaging-guided cancer therapy has great significance in biomedicine.We mainly focus on the preparation and application of AIEgens-functionalised inorganic-organic hybrid materials.AIE chromophores were introduced into different mesoporous materials by a post-grafting method.The obtained materials emit strong blue fluorescence under UV irradiation and have excellent biocompatibility,showing good performances in drug loading,p H controlled drug release and cell imaging.In addition,AIEgens and carboxylic groups dual functionalised hydroxyapatite rods are prepared by the co-condensation method.The obtained material exhibits good performances in explosive PA detection and drug delivery.This work provides references and ideas for designing multifunctional materials those can be applied in biomedicine and chemicals sensing.The main results are as follows:1.The aggregation-induced emission luminogens(AIEgens)tetraphenylethene functionalised mesoporous silica nanoparticles(FMSNs)were prepared through the simple post-grafting method.The obtained material exhibiting a spherical morphology has high surface area and highly ordered mesopores and emits strong blue light under 365 nm UV irradiation.FMSNs have an excellent biocompatibility and can be utilised for cell imaging.It can also serve as an effective drug delivery system for DOX's loading and p H-controlled release.Meanwhile,it can monitor the drug release process based on fluorescence resonance energy transfer(FRET)mechanism by the change of the material's fluorescence emission.This drug delivery system also has a strong lethality to He La cells,showing an excellent anticancer effect.2.AIEgens-functionalised mesoporous bioactive glass(FMBG)nanoparticles were prepared via the simple post-grafting method.The obtained nanoparticles with sizes of 60-100 nm emit strong blue light centered at 482 nm upon UV irradiation.FMBG also has a good biocompatibility and can be applied in cell imaging.What's more,FMBG has a high DOX loading capacity of 250.74 ?g mg-1 and excellent degradability in acid environment which can increase both the carrier's penetration ability and the drug release efficiency,which further leads to an enhanced tumor inhibition effect.3.Aggregation-induced emission luminogens(AIEgens)and carboxylic groups(-COOH)dual functionalised hydroxyapatite rods were synthesized by a one-pot condensation process.The obtained material emits strong sky blue light under UV irradiation in solutions and the solid state,exhibiting typical AIE property.Such a material can serve as an efficient fluorescent sensor for the detection of the explosive picric acid(PA)in water,with a quenching constant of 3.3×104 M-1.In addition,the obtained material with aboundant-COOH functional groups can react with the drug molecules such as anticancer drug doxorubicin(DOX)through hydrazone bond,which is quite stable in alkaline station but cleaves quickly in an acid condition.Thus,the prepared material can serve as an effective p H-triggered drug release system,showing potential application in biomedicine.