Theranostic Nanoparticles Laden In Macrophages For Targeting Tumor Cells

Compared to traditional cancer treatment approaches,PTT reveals efficient,minimally invasive and easily combined with other therapeutic approaches that has drawn considerable attention.As a common strategy in tumor targeting,almost all nanoparticles?NPs?delivered into tumors are based on the enhanced permeability and retention?EPR?effect.However,NPs are exogenous materials,which are recognized by the immune system and cleared by the liver and kidney severely restrict the accumulation of NPs in human body.Cell-mediated strategy can overcome this predicament that can help the NPs effectively circumvent the biological barriers and accumulate in tumor.Such as macrophages and mesenchymal stem cells have been reported as delivery vehicles to carry NPs into tumor.In this work,two kinds of Fe-DA nanoparticles,P[Fe-DA]-NPs and Fe-PDA-NPs,were prepared by one-step method with DA and FeCl₃.The biocompatibility and stability of P[Fe-DA]-NPs and Fe-PDA-NPs were improved by PVP.PH,different solvents,ratio,polymerization time and UV-vis absorption of the two Fe-DA nanoparticles were studied.We determined the preparation process of Fe-DA nanoparticles.The structure of P[Fe-DA]-NPs and Fe-PDA-NPs were determined by FT-IR.The size of NPs was about 60nm.MTT toxicity test showed that the cytotoxicity of P[Fe-DA]-NPs was less than that of Fe-PDA-NPs.At 4 h,the cell survival rate of P[Fe-DA]-NPs was over 90%,and the photothermal conversion efficiency of P[Fe-DA]-NPs was about 30%,which could be used as photothermal materials for photothermal therapy.And then,macrophages mediated Fe-DA nanoparticles systems were constructed:P[Fe-DA]-laden macrophage and Fe-PDA-laden macrophage.In vitro,P[Fe-DA]-laden macrophage had strong photoacoustic signals than Fe-PDA-laden macrophage,which can be used for photoacoustic imaging.In addition,P[Fe-DA]-laden macrophage can convert the absorbed light energy into heat energy and effectively kill tumor cells.In vivo,photoacoustic imaging was combined with photothermal therapy,under 808 nm irradiation of laser,the temperature achieved by P[Fe-DA]-laden macrophage were able to ablate tumor sites.After 24 days,the tumors were significantly suppressed.There were no abnormal liver and kidney functions.Therefore,the P[Fe-DA]-laden macrophage hold great potential in the future clinical cancer therapy.