Antibacterial And Antitumor Activities Based On Multifunctional Conjugated Polymer Composites

Every year,tens of thousands of humans die from cancer and pathogen infection in the world.Therefore,the diagnosis and therapy of cancer and pathogen infection are of vital importance.Within this context,this paper is divided into the following two parts.One is to propose a diagnosis and therapy strategy for pathogens detection and differentiation,and construct wearable flexible bioelectronic antibacterial therapy devices.The other is to monitor the metabolic process of cancer cells by using fluorescence resonance energy transformation(FRET)strategy,and develop a bioelectronic tumor treatment platform in combination with the plant photosynthesis system.Firstly,based on FRET of the conjugated polymer-quantum dot hybrid material,an integrated diagnosis and treatment platform for pathogen identification and killing has been developed.The hybrid material is composed of cationic poly(fluorene-altphenylene)derivative(PFP)and water-soluble anionic Cd Se/Zn S quantum dots(QDs).There was an efficient FRET between QDs and PFP due to the electrostatic interaction and spectral overlap.When interacting with various pathogens,the FRET between PFP and QDs was weakened due to the competitive binding of PFP and various negatively charged pathogens,leading to the change of fluorescence intensity to achieve the distinction of different pathogens.Light-controlled hybrid material antibacterial system provides an integrated diagnosis and treatment platform for pathogens identification and killing.Secondly,a new electrical stimulation therapy based on conjugated polymer nanoparticles was proposed.We found that conjugated polymer nanoparticles could generate holes followed by oxidizing water molecules to produce reactive oxygen species(ROS)under low-voltage electric field(0.8 V).Based on this treatment strategy,a flexible wearable bioelectronic device“electronic band aid”was designed and fabricated for efficiently treating pathogen infection.Electronic band aid possessed the properties of broad spectrum,good bactericidal activity and well inhibition of resistant bacteria.Animal experiments showed that the electronic band aid exhibited a good therapeutic effect on S.aureus infection with a sterilization efficiency of more than 80%.Significantly,Combination of ink-jet printing technology,it is easy to customize and large-scale production,and promotes the development of biological functional materials in the application of flexible electronic devices.Thirdly,a H₂O₂ responsive fluorescent probe based on FRET was designed to detect choline consumption in cells.The fluorescent probe composed of negatively charged Cd S/Zn S QDs and positively charged fluorescein(FB)modified with borate ester.Owing to the hydrolysis of borate ester group caused by H₂O₂,FRET was produced between QDs and FB.The detection of H₂O₂ was realized by calculating the change of fluorescence ratio.Furthermore,in combination of ACh E/Ch Ox cascade reaction,the process of choline consumption in cancer cells was monitored.Lastly,we developed conjugated polymer/chloroplast composite system for cancer therapy,where the conjugated polymers PBF possessed strong light harvesting ability,significantly improving the utilization rate of chloroplasts to sunlight and accelerating the electron transfer in the light reaction.Combined with the unique nitrogen cycle metabolism of chloroplast,the system showed great tumor inhibition effect and has a good biosafety.Significantly,this work provided a new idea for the further development of tumor therapy platform based on photosynthesis.