关键词: 细菌生物膜, 静电纺丝, 纳米纤维, 细菌耐药性, 细菌感染

Abstract: Bacterial biofilms refer to a three-dimensional structure group containing multiple cells formed by bacteria embedded in extracellular polymers secreted by themselves. Compared with planktonic bacteria, bacterial biofilms have more complex morphological structures and stubborn physiological characteristics that are difficult to remove. Implantable medical device infections and chronic infections caused by bacterial biofilms have a serious impact on patients' physical and mental health and medical burden, which has become a major challenge in the current medical and health field.
In recent years, nanofibers have become the dominant carrier of anti-biofilm agents to cope with bacterial biofilm-induced infections due to their high specific surface area and strong surface design. By blending antibacterial agents with polymers during electrospinning or functionalizing nanofibers after electrospinning, nanofibers with anti-biofilm properties can be obtained. According to the characteristics of bacterial biofilms, a series of nanofibers have been developed to remove bacterial biofilms from the principles of preventing biofilm formation, targeting extracellular polymeric matrix, inhibiting signal molecules, and even achieving the synergy of multiple treatment methods, which has become a promising biofilm treatment strategy.
Specifically, in order to prevent the formation of biofilms, researchers inhibit bacterial adhesion by regulating the diameter of nanofibers and changing the hydrophilicity of fibers or design a surface that enhances fibroblast adhesion to prevent the formation of bacterial extracellular polymers, so that planktonic bacteria cannot form biofilms. In the study of targeted destruction of extracellular polymer matrix, researchers combine nanofibers with microneedle arrays to form composite patches, and transport the drugs loaded on the fibers to the interior of the biofilm by the penetration of microneedles, or combine enzymes and photodynamic therapy that degrade extracellular polymer components onto nanofibers to play a role in targeted destruction. In addition, in the inhibition of signal molecules, the anti-biofilm agents that can inhibit the signal molecules including the quorum sensing quenching enzyme, furan derivatives, and nitric oxide are mainly loaded onto nanofibers, so as to achieve the effective removal of bacterial biofilms.
In summary, nanofibers as a carrier of integrated antibacterial agents or a platform technology that integrates multiple therapeutic methods have emerged in the field of biofilm therapy. Nevertheless, the treatment of bacterial biofilm infection based on nanofibers is still in the ascendant. First, a mixed model of biofilm infection should be established in subsequent studies to evaluate the therapeutic effect. Secondly, in order to avoid drug resistance caused by the use of conventional high-dose antibiotics, antibiotic replacement therapy based on nanofibers should be expanded as far as possible to establish synergistic integrated therapy. At the same time, nanofibers as antibacterial agent delivery carrier also have the problem of explosive release and low release of antibacterial agent. Finally, multi-functional dressings can be established for chronic wounds to broaden application scenarios.

Key words: bacterial biofilm, electrospinning, nanofiber, antibiotic resistance, bacterial infection