EGCG Conjugated Peptides For Wound Dressings To Interfere With Bacterial Biofilm Formation

Globally,approximately 1-2% of the population has suffered or is suffering from chronic wounds.The incidence of clinical chronic wound site infections is upwards of 75% and the formation of bacterial biofilms is considered to be one of the most important causes of chronic wound infections.When bacteria proliferate in the wound site or even develop into bacterial biofilm colonisation,this can have a detrimental effect on the wound microenvironment,further delaying chronic wound healing.Under ideal proliferative conditions,planktonic bacteria form mature biofilms very quickly,with the production of bacterial biofilms being observed at around 72 h.Therefore,rapid intervention in bacterial biofilm formation and effective inhibition of bacterial proliferation from the initial wound stage is an effective means of treating chronic wound infections.However,most of the current clinical means of biofilm inhibition cannot act independently of antimicrobial agents and still require synergistic intervention with antimicrobial agents with varying degrees of cellular and tissue toxicity;antimicrobial-loaded wound dressings,the most widely used modality at present,in which the use of antibiotics and the long-term release of subinhibitory concentrations of antimicrobial agents can easily lead to the development of bacterial resistance,making subsequent inhibition of biofilm The use of antibiotics and the long-term release of sub-inhibitory concentrations of antimicrobial agents can easily lead to the development of bacterial resistance,which can make the subsequent inhibition of biofilm formation extremely difficult.In this paper,a rapid,safe and effective intervention system for bacterial biofilm formation was developed,using a natural flavonoid,epigallocatechin gallate(EGCG),instead of traditional antimicrobial agents,and loading it into nanofibre membranes to instantly kill planktonic bacteria by recognising and releasing it in response to the p H of the wound microenvironment.At the same time,a positively charged cationic antimicrobial peptide FWKRIVRKIRKLLV(hereafter abbreviated as FW14)was covalently grafted onto the surface of the nanofibre membrane to bring into play the broad-spectrum antimicrobial properties of the peptide,which,in collaboration with EGCG,can rapidly touch and kill planktonic bacteria,solving the problem of antibiotic resistance,and can effectively improve the intervention and inhibition of bacterial biofilms on the surface of chronic wounds by wound dressings.The principle research substance and discoveries are as per the following.1.polyvinyl alcohol(PVA)and polyacrylic acid(PAA)were selected as electrostatic spinning substrates,and EGCG was encapsulated in the nanofibres to produce PVA/PAA/EGCG nanofibre films loaded with different mass fractions of EGCG.EGCG was effectively released from the PVA/PAA/EGCG nanofibre films to achieve inhibition of planktonic bacteria,prevention of biofilm formation and antioxidation The aim is to achieve responsiveness to the infected environment and modulation of bacterial inhibition at the wound with the help of the p H responsiveness of the fibre structure.2.1-(3-dimethylaminopropyl)-3-ethylcarbodiimide(EDC)/N-hydroxysuccinimide(NHS)surface grafting was chosen to load FW14 onto the surface of PVA/PAA nanofibre membranes,and PVA/PAA@FW14 nanofibre membranes with different grafting concentrations were prepared to construct a touch fast antibacterial system,thereby inhibiting biofilm formation on the wound surface.The system was also investigated for its ability to inhibit planktonic bacteria and biofilm formation,in preparation for the subsequent experiments on the effective synergy between peptides and EGCG.3.The PVA/PAA ratio was chosen as 1:1,the mass fraction of loaded EGCG was 10 wt%,and the grafting concentration of FW14 was 0.5 mg/m L,and the PVA/PAA/EGCG@FW14nanofiber membrane was prepared.The synergistic mechanism of antibacterial and biofilm formation inhibition of FW14 and EGCG was investigated to achieve the synergistic effect of inhibiting the initial planktonic bacteria on the wound surface and inhibiting biofilm formation.The antioxidant properties and biocompatibility of PVA/PAA/EGCG@FW14 nanofibre membranes were also investigated.