Preparation And Photodynamic Antibacterial Activity Of Novel Graphene Nanodrug Carriers

As we all know,pathogen infection poses a great threat to human health and life.In order to treat and prevent this kind of infection,antibiotics are widely and frequently used.However,the increasingly prominent problem of bacterial resistance makes the current antibiotic based antimicrobial therapy inefficient.Therefore,researchers have to actively explore new non antibiotic and non drug antimicrobial strategies We should deal with the infection of drug-resistant bacteria.Antimicrobial photodynamic therapy is a potential alternative to the treatment of bacterial infection.However,due to the strong hydrophobicity and poor photostability of most photosensitizers,it has little impact on the survival ability of organized biofilm bacteria,which limits its clinical application.Drug carriers based on nanotechnology have attracted extensive attention due to their good drug targeting and biocompatibility.In recent years,graphene and metal organic frameworks(MOFs)as the representative of nanomaterials have shown great potential in drug delivery and photodynamic or photothermal therapy due to their unique structure and physicochemical properties.Based on this,functional graphene(PEI-G)and zeolitic imidazole framework(ZIF)were prepared by a simple wet chemical method and used as the drug carrier of photosensitizer chlorin e6(Ce6).By combining nanomaterials with photodynamic therapy,the antibacterial effect of photosensitizer was maximized.The main contents of this paper can be divided into the following two parts1.Dual enhanced anti-bacterial strategy based on high chlorin e6-loaded polyethyleneimine functionalized grapheneWe have prepared highly loaded photosensitizer chlorin e6(Ce6)supported on polyethyleneimine functionalized graphene(PEI-G)nanocomposites PEI-G@Ce6,Ce6 in PEI-G@Ce6 The drug loading was about 32.91%,and the composite nano material was stable PEI-G@Ce6 It not only improves the photostability of free photosensitizer Ce6,but also maintains the ability of photosensitizer Ce6 to produce singlet oxygen The composite nanomaterials have broad-spectrum antibacterial properties,play the physical antibacterial role of PEI-G and photodynamic role of photosensitizer Ce6,and have good antibacterial activities against Gram-positive bacteria such as Staphylococcus aureus and methicillin-resistant Staphylococcus aureus,Gram-negative bacteria such as Escherichia coli and Pseudomonas aeruginosa.2.Construction of efficient antibacterial nanocomposites based on polyethyleneimine functionalized graphene(PEI-G)and metal organic framework nanomaterials(ZIF-67)In the second part,photosensitizer Ce6 was loaded into the composite carrier of metal organic framework nanomaterials(ZIF-67)and polyethyleneimine functionalized graphene(PEI-G)to form the composite nanomaterials(Ce6/PEI-G@ZIF-67).The characteristic peaks and functional groups of the composite were characterized.Through in vitro antibacterial experiment and wound infection healing experiment,it was proved that Ce6/PEI-G@ZIF-67 composite nano material had good antibacterial effect on a variety of bacteria,which provided a new idea for improving the antibacterial efficiency of clinical wound bacterial infection.