Diagnosis of Physical Stimuli Response Enhances the Anti‐Quorum Sensing Agents in Controlling Bacterial Biofilm Formation

Biofilm is a self-assembled microbial community that attached each other in inherent surface and encapsulated by extracellular polymeric substances. The mechanism of biofilm is one of the important virulence factors in Gram-negative bacteria, which not only difficult to eradicate with existing antibiotics treatment but also enables bacteria to be a major problem in clinical settings. Importantly, the cell–cell communication process is helped to provide strong mechanical stability and also provide the nutrients to biofilm. In particular, the biofilm cells communicate each other through harmonic signaling molecule is referred as quorum sensing (QS), influenced by QS molecules. Especially, Gram-negative bacteria (GNB) biofilm formation depends on the cell signaling molecules, and it can alter and regulate the metabolic pathways due to the stimulation of toxin genes and other QS signaling molecules, such as N-acylhomoserine lactones (AHL) and oligopeptides. Both the QS molecules are autoinducers, and play an important role in the construction of biofilm behavior in bacteria due to the gene regulations. Therefore inhibition of QS using QS inhibitors is a best choice to eradicate the complete biofilm formation of pathogens, and also promising approach to control severe infections. Recent years, stimuli-responsive drug delivery nanocarriers are the emerging weapons to eradicate the QS genes in controlling of biofilm formation. In this inhibition mechanism, the stimuli-responsive drug delivery nanocarriers are constructed by various natural and chemical sources that enable a considerable alteration in response to intrinsic/chemical stimuli and extrinsic/physical stimuli including temperature, pH, NaCl, redox and enzymes and light sources, ultrasound, near infrared, magnetic sources, and also electrical field. Further, different strategies are fabricated to arrest the QS process of bacteria in clinical field, such as usage of liposoluble drugs, antibiotics, bioactive compounds, and choose the surface of the bacterial tissue for minimize the toxicity effect, and then controlled drug release in the targeted sites using different stimuli. All these factors are promising factors for improve the anti-QS drugs to inhibit the biofilm formation of gram negative bacteria. Hence, the current study of stimuli-responsive drug delivery nanocarriers is the best choice to control the drug release in target sites, and influence on biofilm eradication therapy.