Construction Of Biodegradable Nano-complexes For Bacterial Detection And Antibacterial Application

Currently,the globally growing infections caused by bacteria poses a great threat to human health,leading to a large number of people death every year.Harmful bacteria infect humans through a variety of direct or indirect transmission routes,such as medical devices,daily supplies and food packing.Multifunctional bacterial theranostic systems have attracted extensive attention by virtue of their unparalleled features.Herein,we summarize the recent research progress in multifunctional bacterial imaging and therapy systems,including natural antibacterial compounds,cationic polymers,inorganic nanoparticles and hybrid nanoparticles.Particularly,multiple imaging and antibacterial modalities are systematically discussed,in order to provide a better understanding of the diagnosis and treatment.Moreover,we summarize the recent progress and limitations of antimicrobial materials,and present a series of outlook in developing novel antimicrobial materials in the future.Many types of antibiotics appeared successively since the discovery of penicillin.Due to the excellent inhibitory effect on bacteria,antibiotics are widely used in treating bacterial infections in the clinical therapy.Antibiotics have a very broad-spectrum antibacterial application,nevertheless,abuse of antibiotics and indiscriminate antibiotic treatment have caused the emergence of multiple-drug resistance(MDR).Using antibacterial largely might cause numerous serious problems,such as drug accumulation,and it also leaves a huge hidden trouble to human health in the future.Nowadays,it is urgent to develop multifunctional antimicrobial biomaterials to relieve the pressure brought by “superbugs”.Here,we engineered a novel biodegradable antibacterial nanomaterials,based on poly(glycidyl methacrylate)and tetraphenylethene derivative,with the effective bacterial detection and elimination.The proposed nanoparticles could be utilized as a facile probe for the bacterial detection due to the competing reaction between anionic species in the bacteria cell membrane and the anionic AIE compound.When the nanoparticles meet bacteria,the competing interaction lead to the release of the complexed TPE in cationic polymer and fluorescence emission decrease.Moreover,the well-known principle of electrostatic reaction was skillfully used in our system.The cationic lipophilic polymer could adsorb to the surface of bacterial cell membrane easily and destroy the membrane structure of antibiotic-resistant bacteria post degradation.After biodegradation,the generated carboxyl group will decrease the adsorbtion to the bacterial membrane and neutralizes part of the positive charge in polymer backbone,which averts the long-term effects on bacteria and issues caused by drug accumulation.The proposed system provided an important platform to establish novel antibacterial nanoparticles with bacterial detection and elimination.On the other hand,we constructed a novel complexed biomaterials by employing biodegradable polyamino acid-based polycations and carboxylatopillar[5]arene.The introduction of water-soluble macrocycle could prevent polycation from non-specifically inserting into the membrane of bacteria and improve some other side effects(toxicity,biocompatibility et al.)caused by quaternary ammonium compounds.Due to the abundant positive charges,the antibacterial efficiency of the biomaterials is better than most of other current antibacterial.Additionally,as a polyamino acid-based polymer,which exists in nature broadly,the proposed material is friendly to ecological environment and could biodegrade spontaneously.This supramolecular construct is expected to solve the therapy challenge of multiple-drug resistance in clinical medicine,and overcome the problem of drug accumulation.Furthermore,the proposed system plays an important role in constructing new selectively antibacterial biomaterials,which have great potential for pursuing broadly biomedical applications.