Tumor Targeting Nanoparticles For NIR Controlled Tumor Photothermal & Chemotherapy And Tumor Gene Silence Therapy

Tumor surgical resection,chemotherapy,radiation therapy are the three main tumor treatment methods,but anyone of them has its own limitation.Therefore,looking for an alternative treatment strategy is in full swing.Tumor targeting strategy can utilize tumor special surface markers,tumor special micro tissue structure and special tumor microenvironment.Based on these theory,tumor targeting study develop rapidly recently.Equipped with positive and passive targeting designs,more NPs can enter tumor and gather in there.Consequently,tumor local therapy efficiency can be improved and side effects can be reduced.However,there still are some problems on NPs,such as poor enrichment of tumor area,uncontrollable treatment,strong side effect on normal tissue,and so on.To further reduce side effects and increase therapy efficiency,spatiotemporally--controlled payload release is required.Among controlling methods,light,especially near infrared ray(NIR),is the most accurate and safest way.Therefore,based on the concept of NIR controlled release,we designed two NIR controlled tumor therapeutic NPs.One is a tumor targeted theranostic NP which combines tumor photothermal therapy and chemotherapy.DESIGN: Based with Cu S core,this NP can convert NIR energy into thermal energy;At the same time,the outer layer of the Cu S core is temperature sensitive amphoteric polymer;The inner hydrophobic layer of this polymer can be used to load most of the hydrophobic drugs;At the terminal end of PEG,we conjugated GE11 peptide,which can bind to tumor over expressed EGFR molecule.METHOD: TEM and DLS to test NP diameter and morphological characteristics;Absorbance value was used to test the phase transition temperature of this NP;Temperature change curve and drug release curve under NIR were used to evaluate the NIR triggered PTT and release effects;NP cellular uptake efficiency was detected by flow cytometry and fluorescence microscopy;MTT test was used to detect the killing effect of this NP on tumor cells;3D tumor spheroid models were used to determine the potential tumor penetrating and kill effects in vivo;Under the NIR,the ultrasonic signal was detected to explore the function of the PA imaging of this NP.RESULT: DLS and transmission electron microscope data showed that the NP has a Homogeneous particle size and uniform dispersion;The maximum absorption of this NP is in the infrared spectrum(989 nm);Phase transition temperature range is from 38? to 41 ?;Under the NIR,this NP can effectively generated photothermal conversion and rapidly release chemotherapy;GE11 design can enhance tumor cellular uptake;PTT and NIR triggered drug burst release can effectively kill tumor cell and show a synergistic effect;NP showed good tumor penetration effect and kill effects on 3D tumor spheroid models;This NP has the function of PA imaging.CONCLUSION: Based on the concept of NIR controlling,we successfully designed a tumor targeting therapeutic vector combined with photothermal therapy and burst release chemotherapy effect,and this carrier also has a PA imaging function.The other NP is NIR controlled gene silencing vector modified by multiply tumor targeting strategy.DESIGN: A variety of functional polymers and si RNA molecules were added on the surface of lanthanum core,with the host and guest interaction between azobenzene and ?-cyclodextrin;At the terminal end of PEG,we conjugated tumor targeting peptide(GE11)and a kind of p H responsive peptide TH.METHOD: TEM and DLS to test NP diameter and morphological characteristics;Using spectrometer to test the up-conversion function;Test NP NIR controlled si RNA release function using Cy5-si RNA absorbance detection;NP cellular uptake efficiency was detected by flow cytometry and fluorescence microscopy;Using laser confocal fluorescence microscope to test NP inner cellular traffic pathway;GFP cell model was used to test NIR controlled gene silencing function;3D tumor spheroid model was used to evaluate potential tumor penetrating and killing effects;MTT assay was used to evaluate the biosafety level.RESULT: DLS and transmission electron microscope data showed that the NP has a Homogeneous particle size and uniform dispersion;Emission spectrum of this NP shows a 330-360 ultraviolet band;After 10 min and 20 min NIR treatment,the NP released 41% and 85% of si RNA respectively;The flow cytometry and fluorescence microscopy data showed that the NP targeting modification can enhance tumor cell uptake effect;Confocal results showed that considerable NPs escaped from endosomes in 120 min;GFP showed a NIR space-time controllable gene silencing;NP showed good tumor penetration effect and gene silencing effect on 3D tumor spheroid model.CONCLUSION: Based on the concept of NIR controlled release,we designed a tumor targeting vector that can realize spatiotemporally controlled gene silencing.