Construction Of Nano-silver/Amphiphilic Composite Membrane And Its Inhibition On Bacterial Biofilm Formation

In nature,clinical and industrial equipment,bacteria tend to attach to the surface of the material to form a condition layer,and then cause bacteria to adhere,reproduce,and finally form a biofilm.The existence of bacterial biofilm,especially those formed on tissues or medical devices,often leads to persistent infection,implant failure,or even death.At present,people mainly use the method of grafting hydrophilic polymer on the surface to reduce the adhesion of bacteria on the surface,but the modification process is complex and tedious.Therefore,to find a simple and effective method to remove protein / bacterial fouling and reduce the biological pollution on the surface of materials is still the main research hotspot and difficulty.A kind of amphiphilic carbon material(ACPs)was prepared by hydrothermal carbonization of yeast cell wall.The surface of ACPs is slightly rough,rich in hydrophobic groups(aromatic,aliphatic groups,etc.)and hydrophilic groups(carboxyl,hydroxyl,etc.),which can be evenly dispersed in polar and non-polar solvents.It is an ideal carrier material.Nano-silver is widely used in medical fields,such as antibacterial medical devices,antibacterial rubber products and plastics,antibacterial textile products,antibacterial coatings,glass and ceramics,etc.it is a kind of green antibacterial coating.In this paper,we choose nano-silver as antibacterial agent for research.In this paper,ACPs particles were used as carriers,and polyethyleneimine(PEI)was covalently grafted on the surface of ACPs by amide bond.Then,silver nanoparticles reduced by cyclodextrin were loaded on the surface of amphiphilic materials by electrostatic action.The compound not only did not change the amphiphilic properties of ACPs,but also had high antibacterial properties against staphylococcus aureus,escherichia coli,candida albicans and methicillin-resistant staphylococcus aureus.With the help of amphiphilic properties of ACPs,the amphiphilic materials loaded with nano silver can be dispersed in hydrophobic polymer matrix,such as polyurethane,silicone rubber,thermoplastic polyurethane and silicone rubber.At present,silicone rubber is the main medical material.We choose silicone rubber as the raw material,and mix the amphiphilic biochar loaded with nano silver with hydrophobic silicone rubber matrix to prepare the film of compatibility between granular material and silicone rubber.It not only solves the problem that the application of silicone rubber is blocked due to its own hydrophobicity,but also improves its antibacterial and adhesion resistance due to the addition of nano-silver.In the application of biomedical implants,the colonization and adhesion of bacteria eventually lead to the formation of biofilm,so we studied the effect of blend membrane on the formation of biofilm in vivo/in vitro.Through the in vitro anti biofilm experiment,the blend membrane can effectively inhibit the formation of biofilm.Through in vivo anti biofilm experiment,it is further proved that the blend membrane prepared by nano silver loaded amphiphilic biochar material can effectively inhibit the formation of biofilm.