Rational Construction of Fluorescence Turn-Off Fluorinated Carbon Fiber/Ag Composites and Their Anticancer and Antibacterial Activities

Although fluorinated carbon fiber/Ag composites possess unique structure and special charge distribution and exhibit great potential in numerous fields, their synthesis has long been a headache because of inert chemistry bonds, low surface energy, and easy aggregation. Herein, we first demonstrate a fresh concept of constructing the nanoscale hydrosoluble fluorinated carbon fiber oxide (FCO)/Ag composite and then integrate it as a highly effective targeting nanocarrier and photothermal therapy and antibacterial agent. Chemical introduction of oxygen allows us to controllably deposit Ag nanoparticles (AgNPs) for the first time and further facilitates surface modification with folic acid prelinked bovine serum albumin to induce targeted endocytosis toward tumor cells. The structure adjustment of FCO into nanosize and the decoration of AgNPs endow the composite with much better photothermal property than fluorinated carbon materials, and FCO/Ag also serves as an effective fluorescence quencher for doxorubicin, realizing visual monitor of drug adsorption processes by "turn-off" fluorescence. Meanwhile, both in vitro and in vivo results reveal greatly improved cancer therapeutic effects than single therapy. What is more is that the synergistic interactions of lipophilic fluorine and AgNPs also ensure highly effective antibacterial activity. Our study integrates FCO/Ag as an emerging drug carrier that exhibits excellent targeted efficiency and high photothemal property and reports its unprecedented experimental example in both antibacterial- and anticancer-combined chemo-photothermal therapy.