Preparation And Biomedical Application Of Reduction-Responsive Photothermal Polymer Composites

Coordination polymer-based polymer composites are a new type of functional hybrid material that combines the advantages of organic polymers and coordination polymers(CPs).With adjustable components,easy post-modification and processing,and good biocompatibility,polymer composites possess broad application prospects in biomedical fields such as cancer treatment and antibacterial.On the basis of retaining the channel properties of coordination polymers,the polymer composites exhibit potential to enhance not only the processability and chemical stability of materials,but also the superiority over inorganic and organic components,leading to improved synergistic effects.In this paper,the polyoxometalate-based coordination polymer/polymer composite material was prepared.The synthesized composite material exhibited tunable redox properties,superior near-infrared photothermal activity and good biocompatibility,which could be applied to bacterial biofilms removal and thermal ablation of malignant tumors.The specific content of the research is as follows:(1)Preparation of near-infrared photoresponsive polymer mixed matrix membrane and its application in antibacterial photothermal coating.By regulating charge transfer and surface hydrophilicity and hydrophobicity,a polymer mixed matrix membrane(MMMs)doped with NPCN-Mo nanoparticles was successfully obtained.The composite material improved the chemical stability,mechanical processability and photothermal conversion efficiency of the composite system,and could be employed as an antibacterial coating layer.The inorganic component NPCN-Mo contained in MMMs,its unique near-infrared photothermal activity was derived from the efficient charge transfer between the photoactive CPs host and the keggin-type polyoxometalate guest.Under irradiation at 808 nm,NPCN-Mo showed the broad-spectrum antimicrobial properties with an antibacterial rate of 99.9%against S.aureus and E.coli.The construction of the hydrophilic structure on the surface of the NPCN-Mo mixed matrix membrane endowed the composite with synergistic anti-adhesion and antibacterial properties.PEG-MMMs could reduce bacterial adhesion to the substrate surface,remove biofilm effectively,and be recyclable.The charge transfer strategy and regulation of surface hydrophilic and hydrophobic properties offer a novel research concept for the development of visible light-responsive functional coatings and catalytic systems.(2)Preparation of photothermal nanocomposites activated by tumor microenvironment and its application in thermal ablation of tumors.Overexpression of glutathione(GSH)in tumor lesions is one of the main reasons of tumor drug resistance.In this paper,a nanocomposite particle(Mo-ZIF/PEG)encapsulated by polyethylene glycol phosphatidylethanolamine(DSPE-PEG)was designed.After the redox reaction between Mo-ZIF and GSH,it showed an obvious red-shifted absorption band and enhanced near-infrared photothermal activity,which could effectively kill tumor cells under light conditions.In addition,Mo-ZIF/PEG could be selectively activated at the tumor sites with high near-infrared photothermal conversion efficiency,therefore overcoming the present limitations of photothermal treatment.This nano-drug delivery system based on endogenous tumor components is of tremendous importance for achieving precision tumor treatment and minimizing adverse effects.