Research On Targeted Detection And Delivery Based On Fluorescence Energy Transfer And Composite Cell Membrane

The combination of Fluorescence Resonance Energy Transfer and composite membrane biomimetic nanoplatform will promote the research of tumor diagnosis and treatment due to its specific imaging detection ability and excellent targeting.Therefore,we designed and prepared a protocol that can be used for bioimaging analysis and drug targeted delivery.The specific research contents are as follows:1.Construction of nanoprobes combining FRET and AIE:We designed a FRET nanoprobe(HMSN/DOX/RVRR/PAMAM/TPE)for Furin imaging detection.First,DOX was loaded into HMSN,and RVRR peptide and PAMAM/TPE were used to encapsulate HMSN nanopores to form FRET nanoprobe.When it entered tumor cells,the overexpressed Furin cleaved RVRR peptide sequence blocked at the HMSN nanopore,allowing DOX to be released from the HMSN cavity.At this time,the external tightly conjugated PAMAM/TPE has a certain adhesive effect,which hinders the rapid release of DOX and realizes the effective conjugation of DOX.At this point,TPE/DOX can achieve FRET fluorescence"turn-on"effect.The experimental results show that the FRET fluorescence signal can be applied to the imaging analysis of intracellular Furin,which assists in the specific diagnosis of tumor cells;at the same time,with the continuous release of DOX,it can kill tumor cells and simultaneously realize tumor diagnosis and treatment.2.Construction of multifunctional biomimetic nanoplatform:We prepared DOX-loaded MCF-7 breast cancer cell membrane(MM)and Escherichia coli membrane(EM)coated Fe₃O₄/MnO₂multifunctional biomimetic nanoplatform(Fe₃O₄/MnO₂/MM/EM/D)for targeted drug delivery and bioimaging.First,Fe₃O₄/MnO₂nanoparticles have Fenton-like reactivity and photothermal conversion capability.On the one hand,the efficient fusion of MM and tumor cells can improve the homologous targeting ability;on the other hand,the highly expressed respiratory chain enzyme II(NDH-2)and superoxide dismutation Enzymes(SODs)in EM can catalyze the local production of H₂O₂,thereby enhancing the Fenton-like reaction.Meanwhile,Fe₃O₄/MnO₂/MM/EM/D can achieve targeted delivery of DOX.Therefore,the multifunctional biomimetic nanoplatform not only enhances synergistic therapy,but also shows the great potential of the biomimetic nanoplatform in tumor therapy.