Preparation And Properties Of Multifunctional Copper-based Antibacterial Wound Dressing

Wound inflammation caused by bacterial and other microbial infections is difficult to control with conventional treatment and poses a great threat to public health.This is mainly attributed to the inefficient management of skin wounds using traditional wound dressings.Although this type of dressing is low-cost and widely sourced,it gradually exhibits many shortcomings,such as sudden release drugs,efficacy monitoring,and wound skin wetness.The single function it can provide cannot meet people’s various needs for wound healing.In this paper,three kinds of multifunctional bacteriostatic wound dressings were developed,and their surface morphology,chemical structure,mechanical properties and cytotoxicity were characterized;Its bacteriostatic effect on representative bacteria was tested and its working mechanism was explored.The main contents of this paper are summarized as follows:（1）Copper nanosheets-clove essential oil/polyvinyl alcohol/polyethylene glycol（Cu NSs/PVA-EO/PVA/PEG）bilayer hydrogels were prepared successfully,and the bilayer hydrogels showed better mechanical properties,swelling property,water retention and thermal stability than the single layer.The double layer hydrogel has good bacteriostasis,which still has 96%bacteriostasis after 72 h of continuous bacteriostasis.The effects of double-layer hydrogels are mainly reflected in two aspects:first,the lower Cu NSs/PVA has weak antibacterial activity and excellent biocompatibility;Cu²⁺can promote angiogenesis and accelerate wound healing.Second,the upper EO/PVA/PEG has strong bacteriostasis,which can avoid the infection of bacteria and other microorganisms in the environment.Meanwhile,EO slowly penetrates downward and collaborates with Cu NSs to enhance the bacteriostasis of the lower layer,achieving the effect of slow-release drugs.（2）In order to endow the antibacterial hydrogel with the function of real-time monitoring drug diffusion,CQDs were coated on Cu NSs by using the high fluorescence quantum yield of CQDs and the adhesion of dopamine,and copper nanosheets coated with carbon quantum dots/polyvinyl alcohol were prepared（Cu NSs@CQDs-PVA）hydrogel,fourier transform infrared spectroscopy,scanning electron microscopy,transmission electron microscopy and other characterization showed that the materials were successfully prepared.The composite hydrogel has excellent fluorescence performance.The size of fluorescence ring and copper diffusion ring recorded by real-time photography confirmed that the fluorescence of CQDs can mark the diffusion of copper,that is Cu NSs@CQDs-PVA hydrogel has the function of real-time monitoring as an antibacterial wound dressing.（3）CSNPs were prepared by ion gel method,and copper ion crosslinked chitosan nanoparticles/sodium alginate/gelatin/polyethylene glycol(Cu²⁺-CSNPs/SA/GEL/PEG)super absorbent sponge was prepared by freeze-drying and soaking in Cu²⁺crosslinked solution.The composite sponge has a porosity of up to 91.45%and a water vapor permeability of 761.1 g/m²/day,which can absorb 377.25%of its own mass of water.When used as a wound dressing,the composite sponge can absorb wound exudate,has good breathability,and can maintain appropriate wetness of the wound.The composite sponge has good antibacterial activity and no cytotoxicity,which has great potential as a wound dressing.