The Preparation And Characterization Of Silver Nanoparticles Coated Central Venous Catheters

With the rapid development of modern medical technology,as one of the intrusive catheters,central venous catheter(CVC)has been widely used in intensive care units(ICU)and general wards to provide venous access for the administration of medications,hemodialysis,hemodynamics monitoring,intravenous feeding,etc.However,the use of CVC is associated with the bacterial colonization and an increased incidence of catheter-related blood stream infections(CRBSIs).CRBSIs are a common cause of hospital-acquired infections,which increase the economic burden on patients and sometimes even cause death.Therefore,the application of anti-infective catheters is of important clinical significance in therapy and prognosis of CRBSIs.Silver has broadspectrum antimicrobial activity,and as such the use of silver-impregnated CVCs has clinical significance.Furthermore,the antibacterial effect and clinical safety of silverimpregnated CVCs are not yet clear,which need to be further studied.In the present work,we developed a facile biomimetic strategy to decorate uniformly small and well dispersed silver nanoparticles(Ag NPs)on CVC surface.The proposed method can be easily applied on all types of CVCs,and revealed both good antibacterial activity and good biocompatibility.This Ag NPs coated CVC may reduce the incidence of CRBSIs.The main progressed and achievements of this dissertation are outlined as following:1.Inspired by mussel adhesive proteins,dopamine was used to form thin polydopamine layer and induce Ag NPs formation without additional reductants or stabilizers in silver nitrate solution.The chemical and physicochemical properties of Ag NPs coated CVC were characterized by atomic force microscopy(AFM),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),static water contact angle(CA)and Raman spectroscopy.The results showed that the CVC surface was successfully coated with compact Ag NPs.The Ag NPs were significantly well separated and spherical with a size of 30-50 nm.The Ag NPs dosewas dependent on the silver nitrate solution concentration.2.Antibacterial activity was investigated by zone of inhibition(Zo I)assay,fluorescence microscopy and SEM using Staphylococcus aureus(S.aureus).The results showed that all the Ag NPs coated samples exhibited good antibacterial activity.The antibacterial activity was dependent on the Ag NPs dose.3.The toxicity of the Ag NPs/polydopamine/CVCs composites was evaluated by WST-1,fluorescent staining methods and SEM observation.High Ag NPs dose showed excellent antibacterial activity while associated with obvious cytotoxicity.The appropriate content of Ag NPs coated CVCs could exhibit improved biocompatibility and maintained evident sterilization effect.It is promising to design mussel inspired silver releasing CVCs with both antimicrobial efficacy and biological safety.