Infection Resistance in PTFE Artificial Vascular Grafts via Antibacterial Surface Engineering

Postoperative graft infection is one of the serious complications of artificial vascular graft implantation surgery, which easily leads to graft exposure, suppuration, thrombosis, anastomotic rupture and even systemic sepsis, seriously threatening the life safety of patients and often requiring secondary surgical removal of infected grafts. Synthetic vascular grafts are foreign bodies in vivo, which are easy to adhere to bacteria in blood and tissue fluid after implantation, forming bacterial biofilms on the graft surface. Once the biofilm is formed, it can resist the killing effect of antibiotics and body immune cells, resulting in persistent refractory infection. Antibacterial surface engineering technology effectively solves the infection problem of PTFE artificial vascular grafts, constructing efficient and durable antibacterial functional layers on the PTFE surface, realizing active anti-bacterial adhesion and sterilization, and greatly reducing the incidence of postoperative graft infection PTFE SHEET.

The core principle of antibacterial surface engineering for PTFE vascular grafts is to transform the inert and bacteria-adhesive PTFE surface into an antibacterial and anti-fouling functional surface through physical activation, chemical grafting and biological modification, without affecting the excellent mechanical properties and hemocompatibility of PTFE substrates. Traditional antibiotic soaking and simple coating methods have poor durability, and the antibacterial components are easy to lose in a short time after blood flushing, unable to achieve long-term anti-infection effect. Modern antibacterial surface engineering adopts covalent grafting, nano-fixation and composite structural design to realize stable and long-term antibacterial function of PTFE vascular grafts, covering the high-risk infection period after surgery and long-term in-vivo service cycle.

Common antibacterial surface engineering technologies for PTFE vascular grafts mainly include nano-antibacterial modification, cationic antibacterial grafting, natural antibacterial component coating and anti-biofilm surface structure design. Nano-silver and nano-zinc oxide antibacterial modification is the most widely used technology. Nano-antibacterial particles are stably fixed on the surface of PTFE TUBE vascular grafts through surface activation treatment, which can continuously release trace antibacterial ions, destroy bacterial cell structure, inhibit bacterial reproduction and biofilm formation, and have efficient killing effect on common pathogenic bacteria such as Staphylococcus aureus and Escherichia coli causing vascular graft infection.

Cationic polymer antibacterial grafting technology constructs positively charged functional layers on the PTFE surface, which can adsorb and crack negatively charged bacterial cell membranes through electrostatic interaction, realizing contact sterilization. This physical sterilization method will not produce drug resistance and has good biological safety. Natural antibacterial components such as chitosan and tea polyphenols are also widely used in antibacterial modification of PTFE vascular grafts, which have excellent antibacterial performance and biocompatibility, can effectively inhibit bacterial adhesion, and promote tissue repair and healing at the same time. The anti-biofilm micro-structure design can change the surface micro-topography, prevent bacterial adhesion and colonization from the source, and inhibit the formation of bacterial biofilms.

Antibacterial surface engineering modified PTFE vascular grafts have dual anti-infection mechanisms of anti-bacterial adhesion and active sterilization, which can effectively prevent acute postoperative infection and long-term latent infection. Clinical application data shows that the infection rate of antibacterial modified PTFE vascular grafts is reduced by more than 60% compared with unmodified grafts, and the incidence of biofilm-induced refractory infection is almost eliminated. At the same time, the antibacterial modification process has no adverse effect on the hemocompatibility, mechanical stability and endothelialization performance of PTFE grafts, ensuring the comprehensive clinical performance of vascular prosthetics.

With the continuous upgrading of antibacterial surface engineering technology, multi-functional antibacterial modification integrating anti-infection, anticoagulation and anti-inflammation has become the mainstream trend. The new generation of antibacterial PTFE artificial vascular grafts can comprehensively prevent postoperative infection, thrombosis and inflammatory stenosis, greatly improve the surgical success rate and long-term patency rate, and provide safer and more reliable artificial vascular solutions for clinical vascular reconstruction surgery.