Guanidine and Galactose Decorated Nanophotosensitizer with Oxygen Self‐Sufficient Capability for the Localized Ablation of Oral Biofilm

Abstract

Dental caries is a common disease caused by plaque biofilms, which are important pathogenic factors in many diseases. When hosts are overexposed to dietary sugars, pathogens such as Streptococcus mutans (S. mutans) and other cariogenic bacteria, metabolically assemble an extracellular matrix rich in exopolysaccharides to form a disease‐causing biofilm, in which the microenvironment is characterized by regional hypoxia, low pH, and nutritional deprivation. Current antimicrobials with inadequate penetration and a lack of pathogens targeting the biofilm do not degrade the protective matrix within the biofilm. In this study, a guanidine and galactose decorated nanophotosensitizer with oxygen self‐sufficient capability, p(GF/GEF)‐I, is developed to enhance the permeability of biofilms by positively charging the particle surface and easily binding to the bacteria within the membrane through electrostatic interactions. 90% of the biofilm on enamel surface is eliminated after treatment with p(GF/GEF)‐I under laser irradiation. Notably, the nanophotosensitizer inhibits the recolonization of dental biofilms by S. mutans, preventing secondary infections. Furthermore, dental caries in a rodent model are reduced with exposure to nanophotosensitizer. p(GF/GEF)‐I is a significantly higher efficacy without damaging the surrounding soft tissue. With further development and optimization, p(GF/GEF)‐I shows significant potential as a phototherapeutic agent for the treatment of biofilm‐induced diseases.

Self-Assembled Borneol-Guanidine-Based Amphiphilic Polymers as an Efficient Antibiofilm Agent

“…Bacterial infections with drug-resistant bacteria pose a major challenge in treating the infection, and biofilm formation at the adhesion interface contributes significantly to drug resistance. , About 65% of microbial infections and 80% of chronic infections in humans are biofilms-associated according to the U.S. National Institutes of Health. − A biofilm is a three-dimensional microbial community encapsulated in self-secreted extracellular polymeric substances (EPS) that are composed of polysaccharides, proteins, lipids, and extracellular DNA. ,, Bacteria in biofilms are 10–1000 times more resistant to antibiotics than plankton bacteria. The densely packed EPS prevents the bacteria from being attacked by the host immune system , and restricts the activity of antibacterial agents by limiting drug penetration, enhancing drug efflux and quorum sensing. ,− Recent antibiofilm strategies include disturbing the synthesis of EPS, interfering with metabolic activity, or directly killing persister cells. ,, The use of high-dose antibiotics is commonly recommended for treating biofilm-associated infections caused by bacteria with a low metabolic rate. However, overuse of antibiotics can result in the emergence of multiresistant bacteria, thereby rendering antibiotics ineffective and leading to recurrent infections. ,− To combat bacterial and biofilm-related infections, alternative antibacterial agents capable of penetrating deep biofilms are urgently needed. − …”

Size-dependent magnetomechanically enhanced photothermal antibacterial effect of Fe3O4@Au/PDA nanodurian

“…3–5 In recent years, the widely explored nanoplatforms offered innovative approaches to combat bacterial infections. 6–11 Unlike traditional antibiotics which were only capable of directly inhibiting specific bacterial metabolic processes, nanoplatforms can assume multiple functions concurrently, thereby mitigating the emergence of bacterial resistance. 12–20 Furthermore, a range of stimulus-activated nanoplatforms have been designed, using ultrasound, 21 microwave, 22 light 23–27 and magnetic fields 28–31 as sources of stimulation.…”

Oxygen‐Free Polycationic Photosensitizers for Treatment of Periodontal Inflammation

“…However, the oral microbial ecosystem is complex, and periodontal infections can also be induced by anaerobic pathogenic bacteria and their associated biofilms, where conventional aPDT would be limited by the lack of oxygen. [16,17] In addition, aPDT is known to exhibit different damage against Grampositive and Gram-negative bacteria due to their different surface membrane structures. [18,19] Because of these issues, a highly efficient oxygen-free photosensitizer is needed for the application of aPDT-mediated treatment of periodontal disease.…”

“…[27,28] The presence of stubborn bacterial biofilms represents another potential barrier to the application of aPDT. [16,29] Abundant extracellular substances produced by the colonizing bacteria render biofilms relatively dense and impenetrable to drugs. Notably, it has been reported that nonenzymatic lectins are widespread in biofilms, and these lectins have a strong affinity for polysaccharides, which serve as important bacterial nutrients.…”