Pluronic And Biomimetic Nanoparticles Based On Cancer Cell Membranes For Inhibiton Of Tumor Metastasis

Maligant tumor is a major disease that endangers human health,and the breast cancer occupies the first position of the female cancer incidence rate.Metastasis is the major cause of the high mortality of the breast cancer patients.Currently,many strategies of tumor treatments including the surgery,chemotherapy,radiotherapy,et.al have been applied in clinic.However,none of them have made significant achievements.Thus,it is highly desirable to explore new strategies to effectively inhibit the breast cancer metastasis.In present work,we mainly proposed two new strategies for the inhibition of breast cancer metastasis.One is the exploration of the adjuvant therapeutic potentials in the inhibition of metastasis of Pluronics which were commonly used for the drug delivery carriers.The other one is the construction of a novel cancer cell biomimetic nanosized drug delivery system for homotypic targeting the primary tumor and metastatic cancer cells.The 4T1 tumor cell membrane(CMs)behaved as the outer shell.The inner core is a paclitaxel(PTX)-loaded polymeric nanoparticle prepared from the poly(caprolactone)(PCL)and pluronic copolymer F68(PPNs).The final cancer cell membrane-coated nanoparticles(CPPNs)with the core-shell structure were obtained.The mentioned two strategies were both applied to inhibit the breast tumor growth and metastasis.Firstly,we evaluated the in vitro anti-metastasis effects of the commonly used Pluronic copolymers including Pluronic P85,P123,L61,F68,F108 and F127.The results showed that the Pluronic P85 and P123 could significantly inhibit the migration and invasion of 4T1 cells.Moreover,it was found that better anti-metastasis effects of Pluconics could be achieved with the HLB between 8 and 16.Based on this,Pluronic P85and P123 were used to investigate the anti-metastasis potentials in vivo.We found that both of them could effectively inhibit the tumor metastasis in vivo.In addition,the co-administration of them with the free doxorubicin(DOX)could further simultaneously inhibit the tumor growth and metastasis.The anti-metastasis effects of Pluronic P85 and P123 could be due to the down regulation of matrix metalloproteinase-9(MMP-9)proteins.Then we prepared the 4T1 CMs through the hyposmosis treatments of the 4T1 cells.The PPNs were self-assembeld.Finally,the new nanoparticles CPPNs were constructed by the extrusion of the mixture of CMs and PPNs.We investigated the physicochemical properties of CPPNs.The results showed that the CPPNs exhibited a compact and spherical morphology with an average particle size of 175.4±0.6 nm.The surface charge of CPPNs was determined to be-18.2±0.7 mV.CPPNs showed high colloidal stability.The surface proteins were remained on the CPPNs,such as TF-antigen,E-cadherin,CD44,CD326 and CD47.The expression levels of the surface markers including TF-antigen,E-cadherin and CD47 on the 4T1 primary tumor and metastatic tumor cells were similar to each other.In the in vitro release experiments,the PTX loaded in CPPNs could be sustainedly released into the surrounding medium until the end.To investigate the in vitro targeting capability of CPPNs to the 4T1 cells.The internalization of CPPNs on the 4T1 cells were far more than the other negative controls.And no significant difference of cellular uptake on the non-4T1 cells such as mice lung fibroblast(WML2)cells were observed in the CPPNs and the other groups.These results suggested that CPPNs showed superior affinity to the 4T1 cells.The cytotoxicity of CPPNs were also enhanced in the 4T1 cells.Moreover,the lower cellular uptake in the mouse macrophage RAW264.7 cells indicated CPPNs could decrease the internalization of the macrophage cells.In the in vivo experiments,the blood circulation time of CPPNs were significantly higher than the PPNs without cell membranes,and it could simultaneously distributed to the tumor tissues and lung metastatic nodules.The accumulation of CPPNs in the tumors and lung tissues were higher than the PPNs.In the 4T1 orthotopic mammary tumor metastasis model,the inhibition rate of the primary tumors of CPPNs was 95.2%and the metastatic nodules decrease by 97.8%.In the 4T1 bloodstream metastasis model,the pulmonary metastatic nodules decreased by 89.9%.In addition,CPPNs also showed excellent biosafety.In conclusion,Pluronic P85 and P123 with anti-metastasis ability could be therapeutic adjuvants in the construction of drug delivery systems.The cancer cell membrane-coated nanoparticles CPPNs could homotypic target the 4T1 primary tumor and metastatic tumor cells to inhibit the primary tumor growth and metastasis.These two new strategies could be effective approaches for the treatments of breast cancer metastasis.