Eradication of Pseudomonas aeruginosa biofilm using quercetin-mediated copper oxide nanoparticles incorporated in the electrospun polycaprolactone nanofibrous scaffold

Electrospun amine-modified polysuccinimide/polycaprolactone nanofiber hydrogel dressings as antibacterial and hemostatic wound dressing applications

Design and construction of novel dressings with appropriate structure and multiple bio-functions are urgently required for the wound treatment applications. In this study, a series of wound dressings composed of amine-modified polysuccinimide (PSI)/polycaprolactone (PCL) hydrogel nanofibers were fabricated by using the conjugated electrospinning and the chemical crosslinking post-treatment. All the dressings with different PSI/PCL ratios could effectively maintain the fibrous morphology even after the chemical crosslinking process. The ultimate stress and Young's modulus of the PSI-NH2/PCL dressings significantly increased with higher PCL content. In particular, when the proportion of PCL reached 40 % (with a PSI/PCL mass ratio of 60/40), the PSI-NH2/PCL dressing exhibited the most excellent mechanical properties, with a Young's modulus of 31.9 ± 8.9 MPa and an ultimate stress of 7.4 ± 0.4 MPa, which were significantly higher than the other samples. Furthermore, all samples exhibited a high swelling ratio of over 350 %, although a noticeable decrease in swelling properties was observed when the content of PCL increased. In addition, all the PSI-NH2/PCL dressings showed a high antibacterial activity (> 99 %) against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), which demonstrated that the addition of PCL has no significant influence on the antibacterial activity of the PSI. Moreover, all the PSI-NH2/PCL nanofiber hydrogel dressings had excellent biocompatibility to human dermal fibroblasts (HDFs). Importantly, all the PSI-NH2/PCL nanofiber hydrogel dressings presented excellent hemostatic capacity. Notably, even the dressing with the highest PCL content still demonstrated a 71.8 % reduction in bleeding compared to the control group. In summary, our PSI-NH2/PCL nanofiber hydrogel dressings with high absorption, biocompatibility and extracellular matrix (ECM)-mimicking capacities, as well as great mechanical, antibacterial, and hemostatic properties are excellent as a promising wound dressing.

Exploring the antivirulence mechanisms of ZnO-PEG-quercetin nanoparticles: Biofilm disruption, attenuation of virulent factors, and cell invasion suppression against pathogenic Pseudomonas aeruginosa

The dense biofilm architecture and efflux pump activity play critical roles in Pseudomonas aeruginosa infections by hindering the accumulation and long-term efficacy of antibacterial agents within bacterial cells. The development of engineered nanoparticles capable of penetrating the polysaccharide matrix of biofilms represents a promising strategy for addressing bacterial infections. This is the first report on the synthesis of quercetin-functionalized PEGylated ZnO nanoparticles (ZnO-PEG-QUE NPs) and the evaluation of their anti-biofilm activity against pathogenic strains of P. aeruginosa. The synthesized NPs exhibited spherical shapes with an average size of 59.52 nm. ZnO-PEG-QUE NPs demonstrated biofilm inhibitory levels between 49 % and 67 %, and significantly reduced the production of total exopolysaccharides, alginate, and pellicle by 64.61 %-71.69 %, 30.47 %-45.36 %, and 24.22 %-85.97 %, respectively. ZnO-PEG-QUE NPs not only inhibited early-stage biofilm formation but also disrupted mature biofilms, indicating a dual mode of action against both biofilm development and persistence. Based on our findings, ZnO-PEG-QUE NPs effectively eradicated mature biofilms by 67.2 %-72 % and significantly reduced the metabolic activity and viable cells of preformed biofilms to 34.12 %-55.57 % and 6.25-8.15 log CFU, respectively. Electron and fluorescence microscopy analyses also confirmed the antibiofilm potential of ZnO-PEG-QUE NPs. Furthermore, bacterial adhesion and invasion to HDF cells were significantly diminished in the NP-treated groups. The attenuation of efflux pump activity in the NP-treated strains was confirmed using the EtBr-agar cartwheel assay. Taken together, these findings highlight the therapeutic potential of ZnO-PEG-QUE NPs as a novel and effective strategy to combat biofilm-associated infections, warranting further investigation in preclinical models.

Comprehensive strategies for overcoming dental biofilms: Microbial dynamics and innovative methods

Dental biofilm develops through a complex process initiated by the attachment of early colonising bacteria to the surface of teeth. These bacteria use specific adhesion molecules to bind to the enamel, after which they proliferate and secrete an extracellular polymeric substance. As a result, the early colonisers eventually form a resilient, multispecies community encased in an extracellular polymeric matrix, reinforcing the biofilm structure. This matrix enables microbes to withstand the mechanical disruption, evade host immune defences and resist many antimicrobials. Diseases associated with dental biofilm are among the most prevalent oral health issues, highlighting the importance of effective biofilm management in maintaining oral health. This review explores the progression of biofilm development and evaluates various strategies, from conventional antibiotics and herbal medicine to advanced strategies like antimicrobial peptides, nanoparticles, probiotics, cold atmospheric plasma, quorum sensing inhibitors and enzymes. In particular, enzymatic agents such as Dispersin B, DNAases, and glucanohydrolases, including mutanase and dextranase, have shown promise in disrupting the biofilm structure, thereby offering potential avenues for managing dental biofilm.

Targeting Pseudomonas aeruginosa PAO1 pathogenicity: The role of Glycyrrhiza glabra in inhibiting virulence factors and biofilms

Pseudomonas aeruginosa (P. aeruginosa) is a Gram-negative opportunistic pathogen posing serious risks to immunocompromised individuals due to its virulence factors and biofilm formation. This study evaluated the efficacy of methanol extract of Glycyrrhiza glabra (G. glabra) in mitigating P. aeruginosa PAO1 pathogenesis through in-vitro assays, including Minimum Inhibitory Concentration (MIC), biofilm assay, growth curve analysis, pyocyanin quantification, and molecular docking. The extract inhibited PAO1 growth at 5 mg/mL and demonstrated significant antibiofilm activity at sub-MIC levels, reducing biofilm formation by 50.22 %, 22.13 %, and 11.53 % at concentrations of 1.25 mg/mL, 0.625 mg/mL, and 0.312 mg/mL, respectively. Pyocyanin production was also significantly suppressed. Molecular docking revealed that 4-(4-Trifluoromethyl-benzoylamino)-benzoic acid and betulinic acid, identified in the extract, exhibited strong binding affinities (-6.4 kcal/mol and -6.9 kcal/mol) to the QS regulator 7XNJ. These findings underscore the potential of G. glabra as an antipathogenic agent against P. aeruginosa, warranting further investigation into its clinical applications.

Modulating Polyphenol Activity with Metal Ions: Insights into Dermatological Applications

BACKGROUND

The skin represents the first barrier of defense, and its integrity is crucial for overall health. Skin wounds present a considerable risk seeing how their progression is rapid and sometimes they are caused by comorbidities like diabetes and venous diseases. Nutraceutical combinations like the ones between polyphenols and metal ions present considerable applications thanks to their increased bioavailability and their ability to modulate intrinsic molecular pathways.

METHODS

The research findings presented in this paper are based on a systematic review of the current literature with an emphasis on nanotechnology and regenerative medicine strategies that incorporate polyphenols and metallic nanoparticles (NPs). The key studies which described the action mechanisms, efficacy, and safety of these hybrid formulations were reviewed.

RESULTS

Nanocomposites of polyphenol and metal promote healing by activating signaling pathways such as PI3K/Akt and ERK1/2, which in turn improve fibroblast migration and proliferation. Nanoparticles of silver and copper have antibacterial, angiogenesis-promoting, inflammation-modulating capabilities. With their ability to induce apoptosis and restrict cell growth, these composites have the potential to cure skin malignancies in addition to facilitating wound healing.

CONCLUSIONS

Nanocomposites of polyphenols and metals provide hope for the treatment of cancer and chronic wounds. Their antimicrobial capabilities, capacity to modulate inflammatory responses, and enhancement of fibroblast activity all point to their medicinal potential. Furthermore, these composites have the ability to decrease inflammation associated with tumors while simultaneously inducing cell death in cancer cells. Clarifying their mechanisms, guaranteeing stability, and enhancing effective delivery techniques for clinical usage should be the focus of future studies.

Optimizing papermaking wastewater treatment by predicting effluent quality with node-level capsule graph neural networks

Papermaking wastewater consists of a sizable amount of industrial wastewater; hence, real-time access to precise and trustworthy effluent indices is crucial. Because wastewater treatment processes are complicated, nonlinear, and time-varying, it is essential to adequately monitor critical quality indices, especially chemical oxygen demand (COD). Traditional models for predicting COD often struggle with sensitivity to parameter tuning and lack interpretability, underscoring the need for improvement in industrial wastewater treatment. In this manuscript, an optimized papermaking wastewater treatment method is proposed that predicts effluent quality using node-level capsule graph neural networks (PWWT-PEQ-NLCGNN). To improve the accuracy of predicting important effluent COD quality indices, the NLCGNN weight parameters are optimized using the hermit crab optimization (HCO) algorithm. The performance of the proposed PWWT-PEQ-NLCGNN technique demonstrated improvements over existing techniques. Specifically, the proposed strategy achieved 30.53%, 23.34%, and 32.64% higher accuracy; 20.53%, 25.34%, and 29.64% higher precision; and 20.53%, 25.34%, and 29.64% higher sensitivity compared to the water quality prediction model using Gaussian process regression based on deep learning for carbon neutrality in papermaking wastewater treatment system (WQP-GPR-DL-CLPWWTS), the prediction of effluent quality in papermaking wastewater treatment processes using dynamic kernel-based extreme learning machine (POEQ-PWWTP-DKBELM), and the quality-related monitoring of papermaking wastewater treatment processes using dynamic multi-block partial least squares (QRM-PWWTP-DMPLS). These results highlight the potential of the PWWT-PEQ-NLCGNN method for enabling timely and accurate monitoring of wastewater treatment processes.

Therapeutic efficacy of chitosan-based hybrid nanomaterials to treat microbial biofilms and their infections - A review

Antimicrobial resistance, the biggest issue facing the global healthcare sector, quickly emerged and spread due to the frequent use of antibiotics in regular treatments. The investigation of polymer-based nanomaterials as possible antibiofilm treatment agents is prompted by the growing ineffectiveness of conventional therapeutic techniques against these resistant bacteria species. So far, several articles have been published on microbial biofilm eradication using various polymer-based nanomaterials due to their therapeutic efficacy and biocompatibility nature. Despite their potential, a comprehensive review of the chitosan-based hybrid nanomaterials to treat microbial biofilms and their infections is lacking. This review provides a comprehensive investigation of the current state of therapeutic efficacy, various nanoformulations, advantages, limitations, and regulations of chitosan-based hybrid nanomaterials for biofilm treatment. Special attention is given to the application of chitosan-based nanomaterials in wound care, urinary tract infections, and dental biofilms are discussed, highlighting their role in managing biofilm-associated complications. Researchers will be better able to comprehend and develop unique, marketable chitosan-based nanomaterials with increased activity to treat biofilm infections in near future with the aid of this review.

Leveraging bacteria-inspired nanomaterials for targeted controlling biofilm and virulence properties of Pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic pathogen designated as a high-priority pathogen because of its role in major healthcare-associated and nosocomial infections. Biofilm production by these bacteria is one of the adaptive resistance mechanisms to traditional antibiotics, making treatment challenging, especially for immunocompromised patients. P. aeruginosa also produces a variety of virulence factors, which aid in invasion, adhesion, persistence, and immune system protection. Recent advances in nanotechnology-based therapy, notably the application of bioinspired metal and metal-oxide nanomaterials, have been seen as a viable way to control P. aeruginosa biofilm and virulence. Because of its ease of growth and culture, synthesizing metal and metal-oxide nanomaterials using bacterial species has become one of the most environmentally benign green synthesis options. The application of bacterial-inspired nanomaterials is particularly successful for targeted control of P. aeruginosa infection due to interactions with cell membrane components and transport systems. This paper delves into and provides a complete overview of the application of bacterial-inspired metal and metal-oxide nanomaterials to treat P. aeruginosa infection by targeting biofilm and virulence characteristics. The review focused on synthesizing and applying gold, silver, copper, iron, magnetite, and zinc oxide nanomaterials to mitigate P. aeruginosa biofilm and virulence. The underlying mechanism of these metal and metal-oxide nanoparticles in relation to biofilm and virulence features has also been thoroughly discussed. The current review introduces novel approaches to treating and controlling drug-resistant P. aeruginosa using bacterial-inspired nanomaterials as a targeted therapeutic strategy.

Volatiles emitted by Pseudomonas aurantiaca ST-TJ4 trigger systemic plant resistance to Verticillium dahliae

Verticillium dahliae is among the most devastating fungal pathogens, causing significant economic harm to agriculture and forestry. To address this problem, researchers have focused on eliciting systemic resistance in host plants through utilizing volatile organic compounds (VOCs) produced by biological control agents. Herein, we meticulously measured the quantity of V. dahliae pathogens in plants via RTqPCR, as well as the levels of defensive enzymes and pathogenesis-related (PR) proteins within plants. Finally, the efficacy of VOCs in controlling Verticillium wilt in cotton was evaluated. Following treatment with Pseudomonas aurantiaca ST-TJ4, the expression of specific VdEF1-α genes in cotton decreased significantly. The incidence and disease indices also decreased following VOC treatment. In cotton, the salicylic acid (SA) signal was strongly activated 24 h posttreatment; then, hydrogen peroxide (H2O2) levels increased at 48 h, and peroxidase (POD) and catalase (CAT) activities increased to varying degrees at different time points. The malondialdehyde (MDA) content and electrolyte leakage in cotton treated with VOCs were lower than those in the control group, and the expression levels of chitinase (CHI) and PR genes (PR10 and PR17), increased at various time points under the ST-TJ4 treatment. The activity of phenylalanine ammonia lyase (PAL) enzymes in cotton treated with VOCs was approximately 1.26 times greater than that in control plants at 24 h，while the contents of phenols and flavonoids increased significantly in the later stage. Additionally, 2-undecanone and 1-nonanol can induce a response in plants that enhances disease resistance. Collectively, these findings strongly suggest that VOCs from ST-TJ4 act as elicitors of plant defence and are valuable natural products for controlling Verticillium wilt.

Evaluation of MDR-specific phage Pɸ-Mi-Pa loaded mucoadhesive electrospun nanofibrous scaffolds against drug-resistant Pseudomonas aeruginosa- induced wound infections in an animal model

Given the escalating prevalence of drug-resistant wounds, there is a justified imperative to explore innovative and more efficacious therapies that diverge from conventional, ineffective wound healing approaches. This research has introduced a strategy to address multi-drug resistant (MDR) Pseudomonas aeruginosa infections in a chronic wound model, employing MDR-specific phage Pɸ-Mi-Pa loaded onto mucoadhesive electrospun scaffolds. A cocktail of three isolates of P. aeruginosa-specific lytic phages, Pɸ-Mi-Pa 51, Pɸ-Mi-Pa 120, and Pɸ-Mi-Pa 133 were incorporated into varying ratios of fabricated PCL-PVP polymer. These formulations were assessed for their therapeutic efficacy in achieving bacterial clearance in P. aeruginosa-induced wound infections. The study encompassed biological characterization through in vivo wound healing assessments, histology, and histomorphometry. Additionally, morphological, mechanical, and chemical analyses were conducted on the fabricated PCL-PVP electrospun nanofibrous scaffolds. Three clonal differences of the MDR P. aeruginosa-specific phages (Pɸ-Mi-Pa 51, Pɸ-Mi-Pa 120, and Pɸ-Mi-Pa 133) produced lytic activity and were seen to produce distinct and clear zones of inhibition against MDR P. aeruginosa strains Pa 051, Pa 120 and Pa 133 respectively. The average porosity of the nanofibrous scaffolds PB 1, PB 2, PB 3, and PB 4 were 12.2 ± 0.3 %, 22.1 ± 0.7 %, 31.1 ± 2.4 %, 28.0 ± 0.8 % respectively. In vitro cumulative release of MDR-specific phage Pɸ-Mi-Pa from the mucoadhesive electrospun nanofibrous scaffolds was found to be 70.91 % ± 1.02 % after 12 h of incubation after an initial release of 42.8 % ± 3.01 % after 1 h. Results from the in vivo wound healing study revealed a substantial reduction in wound size, with formulations PB 2 and PB 3 exhibiting the most significant reduction in wound size, demonstrating statistically significant results on day 5 (100 % ± 31.4 %). These findings underscore the potential of bacteriophage-loaded electrospun PCL-PVP nanofibrous scaffolds for treating drug-resistant wounds, generating tissue substitutes, and overcoming certain limitations associated with conventional wound care matrices.

Ecofriendly biosynthesis of copper nanoparticles from novel marine S. rhizophila species for enhanced antibiofilm, antimicrobial and antioxidant potential

Marine microorganisms offer a promising avenue for the eco-friendly synthesis of nanoparticles due to their unique biochemical capabilities and adaptability to various environments. This study focuses on exploring the potential of a marine bacterial species, Stenotrophomonas rhizophila BGNAK1, for the synthesis of biocompatible copper nanoparticles and their application for hindering biofilms formed by monomicrobial species. The study begins with the isolation of the novel marine S. rhizophila species from marine soil samples collected from the West coast region of Kerala, India. The isolated strain is identified through 16S rRNA gene sequencing and confirmed to be S. rhizophila species. Biosynthesis of copper nanoparticles using S. rhizophila results in the formation of nanoparticles with size of range 10-50 nm. The nanoparticles exhibit a face-centered cubic crystal structure of copper, as confirmed by X-Ray Diffraction analysis. Furthermore, the synthesized nanoparticles display significant antimicrobial activity against various pathogenic bacteria and yeast. The highest inhibitory activity was against Staphylococcus aureus with a zone of 27 ± 1.00 mm and the least activity was against Pseudomonas aeruginosa with a zone of 22 ± 0.50 mm. The zone of inhibition against Candida albicans was 16 ± 0.60 mm. The antibiofilm activity against biofilm-forming clinical pathogens was evidenced by the antibiofilm assay and SEM images. Additionally, the copper nanoparticles exhibit antioxidant activity, as evidenced by their scavenging ability against DPPH, hydroxyl, nitric oxide, and superoxide radicals, as well as their reducing power in the FRAP assay. The study highlights the potential of the marine bacterium S. rhizophila BGNAK1 for the eco-friendly biosynthesis of copper nanoparticles with diverse applications. Synthesized nanoparticles exhibit promising antibiofilm, antimicrobial, and antioxidant properties, suggesting their potential utility in various fields such as medicine, wastewater treatment, and environmental remediation.

Acceleration mechanism of riboflavin on Fe0-to-microbe electron transfer in corrosion of EH36 steel by Pseudomonas aeruginosa

Riboflavin (RF), as a common electron mediator that can accelerate extracellular electron transfer (EET), is usually used as a probe to confirm EET-microbiologically influenced corrosion (MIC). However, the acceleration mechanism of RF on EET-MIC is still unclear, especially the effect on gene expression in bacteria. In this study, a 13-mer antimicrobial peptide E6 and tetrakis hydroxymethyl phosphonium sulfate (THPS) were used as new tools to investigate the acceleration mechanism of RF on Fe0-to-microbe EET in corrosion of EH36 steel caused by Pseudomonas aeruginosa. 60 min after 20 ppm (v/v) THPS and 20 ppm THPS & 100 nM E6 were injected into P. aeruginosa 1 and P. aeruginosa 2 (two glass bottles containing P. aeruginosa with different treatments) at the 3-d incubation, respectively, P. aeruginosa 1 and P. aeruginosa 2 had a similar planktonic cell count, whereas the sessile cell count in P. aeruginosa 1 was 1.3 log higher than that in P. aeruginosa 2. After the 3-d pre-growth and subsequent 7-d incubation, the addition of 20 ppm (w/w) RF increased the weight loss and maximum pit depth of EH36 steel in P. aeruginosa 1 by 0.7 mg cm-2 and 4.1 μm, respectively, while only increasing those in P. aeruginosa 2 by 0.4 mg cm-2 and 1.7 μm, respectively. This suggests that RF can be utilized by P. aeruginosa biofilms since the corrosion rate should be elevated by the same value if it only acts on the planktonic cells. Furthermore, the EET capacity of P. aeruginosa biofilm was enhanced by RF because the protein expression of cytochrome c (Cyt c) gene in sessile cells was significantly increased in the presence of RF, which accelerated EET-MIC by P. aeruginosa against EH36 steel.

Advances in Regenerative and Reconstructive Medicine in the Prevention and Treatment of Bone Infections

Reconstructive and regenerative medicine are critical disciplines dedicated to restoring tissues and organs affected by injury, disease, or congenital anomalies. These fields rely on biomaterials like synthetic polymers, metals, ceramics, and biological tissues to create substitutes that integrate seamlessly with the body. Personalized implants and prosthetics, designed using advanced imaging and computer-assisted techniques, ensure optimal functionality and fit. Regenerative medicine focuses on stimulating natural healing mechanisms through cellular therapies and biomaterial scaffolds, enhancing tissue regeneration. In bone repair, addressing defects requires advanced solutions such as bone grafts, essential in medical and dental practices worldwide. Bovine bone scaffolds offer advantages over autogenous grafts, reducing surgical risks and costs. Incorporating antimicrobial properties into bone substitutes, particularly with metals like zinc, copper, and silver, shows promise in preventing infections associated with graft procedures. Silver nanoparticles exhibit robust antimicrobial efficacy, while zinc nanoparticles aid in infection prevention and support bone healing; 3D printing technology facilitates the production of customized implants and scaffolds, revolutionizing treatment approaches across medical disciplines. In this review, we discuss the primary biomaterials and their association with antimicrobial agents.

Antibacterial and antibiofilm efficacy of Solanum lasiocarpum root extract synthesized silver/silver chloride nanoparticles against Staphylococcus haemolyticus associated with bovine mastitis

Staphylococcus haemolyticus is a cause of bovine mastitis, leading to inflammation in the mammary gland. This bacterial infection adversely affects animal health, reducing milk quality and yield. Its emergence has been widely reported, representing a significant economic loss for dairy farms. Interestingly, S. haemolyticus exhibits higher levels of antimicrobial resistance than other coagulase-negative Staphylococci. In this study, we synthesized silver/silver chloride nanoparticles (Ag/AgCl-NPs) using Solanum lasiocarpum root extract and evaluated their antibacterial and antibiofilm activities against S. haemolyticus. The formation of the Ag/AgCl-NPs was confirmed using UV-visible spectroscopy, which revealed maximum absorption at 419 nm. X-ray diffraction (XRD) analysis demonstrated the crystalline nature of the Ag/AgCl-NPs, exhibiting a face-centered cubic lattice. Fourier transform infrared (FT-IR) spectroscopy elucidated the functional groups potentially involved in the Ag/AgCl-NPs synthesis. Transmission electron microscopy (TEM) analysis revealed that the average particle size of the Ag/AgCl-NPs was 10 nm. Antimicrobial activity results indicated that the minimum inhibitory concentration (MIC) and maximum bactericidal concentration (MBC) of the Ag/AgCl-NPs treatment were 7.82-15.63 μg/mL towards S. haemolyticus. Morphological changes in bacterial cells treated with the Ag/AgCl-NPs were observed under scanning electron microscopy (SEM). The Ag/AgCl-NPs reduced both the biomass of biofilm formation and preformed biofilm by approximately 20.24-94.66 % and 13.67-88.48 %. Bacterial viability within biofilm formation and preformed biofilm was reduced by approximately 21.56-77.54 % and 18.9-71.48 %, respectively. This study provides evidence of the potential of the synthesized Ag/AgCl-NPs as an antibacterial and antibiofilm agent against S. haemolyticus.

Attenuation of biofilm and virulence factors of Pseudomonas aeruginosa by tetramethylpyrazine-gold nanoparticles

Pseudomonas aeruginosa is often identified as the causative agent in nosocomial infections. Their adapted resistance makes them strong towards antimicrobial treatments. They protect and empower their survival behind strong biofilm architecture that works as their armor toward antimicrobial therapy. Additionally, P. aeruginosa generates virulence factors, contributing to chronic infection and recalcitrant phenotypic characteristics. The current study utilizes the benevolence of nanotechnology to develop an alternate technique to control the spreading of P. aeruginosa by limiting its biofilm and virulence development. This study used a natural compound, tetramethylpyrazine, to generate gold nanoparticles. Tetramethylpyrazine-gold nanoparticles (Tet-AuNPs) were presented in spherical shapes, with an average size of 168 ± 52.49 nm and a zeta potential of -12.22 ± 2.06 mV. The minimum inhibition concentration (MIC) of Tet-AuNPs that proved more than 90 % effective in inhibiting P. aeruginosa was 256 μg/mL. Additionally, it also shows antibacterial activities against Staphylococcus aureus (MIC, 256 μg/mL), Streptococcus mutans (MIC, 128 μg/mL), Klebsiella pneumoniae (MIC, 128 μg/mL), Listeria monocytogenes (MIC, 256 μg/mL), and Escherichia coli (MIC, 256 μg/mL). The sub-MIC values of Tet-AuNPs significantly inhibited the early-stage biofilm formation of P. aeruginosa. Moreover, this concentration strongly affected hemolysis, protease activity, and different forms of motilities in P. aeruginosa. Additionally, Tet-AuNPs destroyed the well-established mature biofilm of P. aeruginosa. The expression of genes linked with the biofilm formation and virulence in P. aeruginosa treated with sub-MIC doses of Tet-AuNPs was shown to be significantly suppressed. Gene expression studies support biofilm- and virulence-suppressing effects of Tet-AuNPs at the phenotypic level.

Recent updates and feasibility of nanodrugs in the prevention and eradication of dental biofilm and its associated pathogens-A review

OBJECTIVES

Dental biofilm is one of the most prevalent diseases in humans, which is mediated by multiple microorganisms. Globally, half of the human population suffers from dental biofilm and its associated diseases. In recent trends, nano-formulated drugs are highly attractive in the treatment of dental biofilms. However, the impact of different types of nanodrugs on the dental biofilm and its associated pathogens have not been published till date. Thus, this review focuses on the recent updates, feasibility, mechanisms, limitations, and regulations of nanodrugs applications in the prevention and eradication of dental biofilm.

STUDY SELECTION, DATA AND SOURCES

A systematic search was conducted in PubMed/Google Scholar/Scopus over the past five years covering the major keywords "nanodrugs, metallic nanoparticles, metal oxide nanoparticles, natural polymers, synthetic polymers, biomaterials, dental biofilm, antibiofilm mechanism, dental pathogens", are reviewed in this study. Nearly, 100 scientific articles are selected in this relevant topic published between 2019 and 2023. Data from the selected studies dealing with nanodrugs used for biofilm treatment was qualitatively analyzed.

CONCLUSIONS

The nanodrugs such as silver nanoparticles, gold nanoparticles, selenium nanoparticles, zinc oxide nanoparticles, copper oxide nanoparticles, titanium oxide nanoparticles, hydroxyapatite nanoparticles and these inorganic nanoparticles incorporated polymer-based nanocomposites, organic/inorganic nanoparticles mediated antimicrobial photodynamic therapy exhibits an excellent antibacterial and antibiofilm activity towards dental pathogens. Finally, this review highlights that bioinspired nanodrugs will be very useful to control the dental biofilm and its associated diseases.

CLINICAL SIGNIFICANCE

Microbial influence on the oral environment is unavoidable; therefore, curing such dental biofilms and pathogens is essential for the impactful reflection of applying biocompatible treatments. In this direction, the current review explains the demand for the nanodrug in inhibiting biofilms for the effective exploration of employing treatments.

Treatment of dental biofilm-forming bacterium Streptococcus mutans using tannic acid-mediated gold nanoparticles

Biosynthesized gold nanoparticles (AuNPs) are highly attracted as a biocompatible nanodrug to treat various diseased conditions in humans. In this study, phytochemical tannic acid-mediated AuNPs (TA-AuNPs) are successfully synthesized and tested for antibacterial and antibiofilm activity against dental biofilm-forming Streptococcus mutans biofilm. The synthesized TA-AuNPs are appeared as spherical in shape with an average size of 19 nm. The antibacterial potential of TA-AuNPs was evaluated using ZOI and MIC measurements; while, antibiofilm efficacy was measured by checking the eradication of preformed biofilm on the tooth model. The ZOI and MIC values for TA-AuNPs are 25 mm in diameter and 4 μg/mL, respectively. The MTT assay, CLSM, and SEM results demonstrate that the preformed S. mutans biofilm is completely eradicated at 4xMIC (16 μg/mL) of TA-AuNPs. Finally, the present study reveals that the synthesized TA-AuNPs might be a great therapeutic drug to treat dental biofilm-forming bacterium S. mutans.