Paclitaxel Organic Nano-framework And Biomimetic Polypyrrole Nanoparticles Combined With Photothermal Therapy For The Treatment And Mechanism Of Colorectal Cancer

Erythrocyte–platelet hybrid membranes coating polypyrrol nanoparticles for enhanced delivery and photothermaltherapyPolypyrrole nanoparticles(PPy NPs)are themselves non-toxic and can generate heat upon near-infrared(NIR)irradiation.Therefore,PPy NPs have been extensivelystudied for photothermal therapy(PTT)of tumors.However,PPy NPs still have certain limitations and challenges in clinical applications because they do not have long-circulation and self-targeting properties.PPy@RBC NPs were obtained by coating the erythrocyte membrane on the surface of polypyrrole,which inherits the characteristics of erythrocyte membrane and has excellent long-circulation characteristics,but the problem of self-targeting is not solved.Reference Professor Zhang Liangfang experiences on erythrocyte–platelet hybrid membrane coating,we fused erythrocytes(RBC)and platelets(PLT)in the surface of PPy NPs,biomimetic polypyrrole nanoparticles were obtained(i.e.PPy@[ R-P] NPs).The experimental result shows that PPy@[R-P] NPs not only have the characteristics of RBC and PLT,but also exhibit long-cycle characteristics and self-targeting properties.After administration of PPy@[R-P] NPs via tail vein,tumor vessels were injured by photothermal stimulation under NIR laser exposure,which induced a large amount of microthrombosis.Due to the existence of PLT membranes,a large number of PPy@[R-P] NPs were successfully recruited to the microthrombosis sites.As a result,the distribution of nanomaterials in the tumor tissues was improved,and excellent photothermal treatment was achieved.The resulting PPy@[R-P] NPs may contribute to anti-tumor PTT.Studies on the mechanism by which On-demand release of CO enhances paclitaxel inhibits tumor growthCarbon monoxide(CO)gas therapy is a promising treatment mode for malignant tumor,which not only does not damage normal cells,but also enhances chemotherapy and promotes tumor cell apoptosis.The chemotherapy which commonly used in clinical practice has a long cycle and poor effect,accompanied by local or systemic side effects.It is assumed that CO gas therapy can make up for the shortcomings of the above chemotherapy.Accordingly,it is proposed to develop an on-demand release of CO to enhance paclitaxel(PTX)inhibition of tumor growth.Herein,the treatment of malignant tumors with CO-enhanced PTX efficacy hasexcellent synergistic effects compared with gas therapy alone or chemotherapy alone.We reported Paclitaxel(PTX)loaded metal-organic framework coated PEGylated(denoted as MCM@PEG-CO-PTX NPs)as theranostics nanoplatforms for near-infrared(NIR)-responded CO-PTX combination therapy.The preparation route of MCM@PEG-CO-PTX is simple and easy.Under Near Infrared(NIR)irradiation,MCM@PEG-CO-PTX can release CO and PTX as needed.Among them,the effect of CO-enhanced PTX can make MCM@PEG-CO-PTX kill cancer cells more effectively.