Disrupting biofilm and eradicating bacteria by Ag-Fe3O4@MoS2 MNPs nanocomposite carrying enzyme and antibiotics

Mathematical modeling for the prediction of biofilm formation and removal in the food industry as strategy to control microbiological resistance

The formation of biofilms in the food industry poses significant economic, social, and public health challenges. Concurrently, mathematical models have emerged as promising tools for investigating microbial contamination and biofilm dynamics. This study evaluates the application of these models, highlighting their ability to identify critical parameters influencing microbial adhesion and to develop strategies for disrupting biofilm formation. Furthermore, it explores how mathematical modeling can address current limitations in food safety, discussing practical challenges such as the complexity of biological systems and the necessity for experimental validation of proposed models. In this context, the review assesses both the potential and the challenges associated with employing mathematical models for microbial control in food processing, examining the specifics of existing models. Additionally, it underscores the need for a comprehensive understanding of biofilm formation mechanisms and control techniques to fully leverage the benefits of these models. The findings demonstrate that mathematical modeling is a viable, innovative, and promising approach for optimizing biofilm prevention and control strategies in the food industry. To achieve more effective biofilm management and ensure consumer food safety, future research should focus on applying these models to various real-world scenarios.

Nanozymes: a promising solution for dental antibacterial applications

Dental diseases pose significant public health challenges globally, affecting millions with conditions exacerbated by microbial-induced inflammation. Traditional natural enzymes, despite their antibacterial and anti-inflammatory capabilities, are limited by operational stability and environmental sensitivity. This review explores the revolutionary realm of nanozyme-artificial enzymes made from nanomaterials-which offer enhanced stability, cost-effectiveness, and ease of modification. We discuss the advent of nanozymes since their first recognition in 2007, emphasizing their enzyme-mimicking capabilities and applications in dental medicine, particularly for dental caries, pulpitis, periodontitis and peri-implantitis. This paper presents a comprehensive analysis of nanozymes' classification, mechanisms, and emerging applications, shedding light on their potential to revolutionize dental antibacterial treatments and addressing current challenges and future perspectives in their development.

An integrated preventive and therapeutic magnetic nanoparticle loaded with rhamnolipid and vancomycin for combating subgingival biofilms

OBJECTIVES

Mechanical debridement supplemented with antibacterial agents effectively eradicates subgingival biofilms formed in the periodontal pockets of severe periodontitis patients. However, the available antimicrobial agents have limited penetrating ability to kill the bacteria encased in the deep layers of biofilms. This study aimed to fabricate a novel magnetic nanoparticle (MNP) loaded with rhamnolipid (RL) and vancomycin (Vanc, Vanc/RL-Ag@Fe3O4) to combat subgingival biofilms.

METHODS

The multispecies subgingival biofilm was formed by periodontal pathogens, including Streptococcus oralis (S. oralis), Streptococcus sanguinis (S. sanguinis), Actinomyces naeslundii (A. naeslundii), Porphyromonas gingivalis (P. gingivalis) and Fusobacterium nucleatum (F. nucleatum). Scanning electron microscope (SEM), confocal laser scanning microscopy (CLSM), and quantitative real-time polymerase chain reaction (qRT-PCR) were used to determine the anti-biofilm efficacy of Vanc/RL-Ag@Fe3O4 with or without a magnetic field on multispecies subgingival biofilms.

RESULTS

The minimal inhibitory concentration (MIC) values of Vanc/RL-Ag@Fe3O4 on S. oralis, S. sanguinis, A. naeslundii, P. gingivalis, and F. nucleatum were 25, 50, 100, 50, and 25 μg/mL, respectively. Vanc/RL-Ag@Fe3O4 (200 μg/mL) reduced the 7-d biofilm thickness from 22 to 13 µm by degrading extracellular polymeric substance (EPS) and killing most bacteria except for tolerant F. nucleatum. A magnetic field enhanced the anti-biofilm effect of Vanc/RL-Ag@Fe3O4 by facilitating its penetration into the bottom layers of biofilms and killing tolerant F. nucleatum.

SIGNIFICANCE

Vanc/RL-Ag@Fe3O4 MNPs can release RL, Vanc, and Ag and eradicate subgingival biofilms by disrupting EPS and killing bacteria. Vanc/RL-Ag@Fe3O4 combined with a magnetic force is a promising approach for combating periodontal infection.

Synergistic Dual Antibacterial Activity of Magnetite Hydrogels Doped with Silver

In this work, we utilized poly-N-isopropylacrylamide (NIPAM), magnetic nanoparticles (MNPs), and silver nitrate to prepare magnetic hydrogel microparticles doped with silver, which exhibited a dual antimicrobial effect. The antibacterial effect of these composites was mediated by the antimicrobial activity of silver and the magnetic hyperthermic induction, which we believe increased biofilm disruption and silver release into the surrounding bacterial biofilms. The prepared particles were characterized by using several analytical techniques. The particles exhibited a porous morphology impregnated evenly with silver nanoparticles, as observed by scanning electron microscopy (SEM). Furthermore, we examined the antibacterial activity of our microparticles against Escherichia coli by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Our findings revealed that the composites demonstrated significant antibacterial activity of up to 81% under magnetic hyperthermia as compared to 45% when samples were heated to the same temperature in a water bath at constant silver concentration. This demonstrates the distinctive inhibitory features of MNPs in enhancing bacterial killing when a magnetic field is applied. The findings of this study lay the groundwork for further exploration of microparticle-based antimicrobial therapies, which can contribute to the development of more advanced wound healing devices and better sterilization methods for medical devices.

Synthesis and characterization of activated carbon-supported magnetic nanocomposite (MNPs-OLAC) obtained from okra leaves as a nanocarrier for targeted delivery of morin hydrate

Introduction

The method of encapsulating the drug molecule in a carrier, such as a magnetic nanoparticle, is a promising development that has the potential to deliver the medicine to the site where it is intended to be administered. Morin is a pentahydroxyflavone obtained from the leaves, stems, and fruits of various plantsmainly from the Moraceae family exhibiting diverse pharmacological activities such as anti-inflammatory, anti-oxidant, and free radical scavenging and helps treat diseases such as diabetes, myocardial infarction and cancer.

Methods

In this study, we conducted the synthesis of a nanocomposite with magnetic properties by coating biocompatible activated carbon obtained from okra plant leaves with magnetic nanoparticles.

Results

Characterization of the synthesized activated carbon-coated magnetic nanocomposite was confirmed by Fourier transform infrared, scanning electron microscopy, dynamic light scattering, and zeta potential. The cytotoxic effects of the drug-loaded magnetic nanocomposite were examined in HT-29 (Colorectal), MCF-7 (breast), U373 (brain), T98-G (Glioblastoma) cancer cell lines, and human umbilical vein endothelial cells healthy cell line.

Discussion

We studied the loading and release behavior of morin hydrate in the activated carbon-coated magnetic nanocomposite. Activated carbon-coated magnetic nanocomposite carriers can show promising results for the delivery of Morin hydrate drugs to the targeted site.

Accelerated healing of intractable biofilm-infected diabetic wounds by trypsin-loaded quaternized chitosan hydrogels that disrupt extracellular polymeric substances and eradicate bacteria

Complex and stubborn bacterial biofilm infections significantly hinder diabetic wound healing and threaten public health. Therefore, a dressing material that effectively clears biofilms and promotes wound healing is urgently required. Herein, we introduce a novel strategy for simultaneously dispersing extracellular polymeric substances and eradicating drug-resistant bacteria. We prepared an ultrabroad-spectrum and injectable quaternized chitosan (QCS) hydrogel loaded with trypsin, which degrades biofilm extracellular proteins. Increased temperature initiated QCS gelation to form the hydrogel, enabling the sustained release of trypsin and effective adherence of the hydrogel to irregularly shaped wounds. To reproduce clinical scenarios, biofilms formed by a mixture of Staphylococcus aureus (S. aureus), Methicillin-resistant S. aureus, and Pseudomonas aeruginosa were administered to the wounds of rats with streptozotocin-induced diabetes. Under these severe infection conditions, the hydrogel efficiently suppressed inflammation, promoted angiogenesis, and enhanced collagen deposition, resulting in accelerated healing of diabetic wounds. Notably, the hydrogel demonstrates excellent biocompatibility without cytotoxicity. In summary, we present a trypsin-loaded QCS hydrogel with tremendous clinical applications potential for the treatment of chronic infected wounds.

Microenvironment-sensitive nanozymes for tissue regeneration

Tissue defect is one of the significant challenges encountered in clinical practice. Nanomaterials, including nanoparticles, nanofibers, and metal-organic frameworks, have demonstrated an extensive potential in tissue regeneration, offering a promising avenue for future clinical applications. Nonetheless, the intricate landscape of the inflammatory tissue microenvironment has engendered challenges to the efficacy of nanomaterial-based therapies. This quandary has spurred researchers to pivot towards advanced nanotechnological remedies for overcoming these therapeutic constraints. Among these solutions, microenvironment-sensitive nanozymes have emerged as a compelling instrument with the capacity to reshape the tissue microenvironment and enhance the intricate process of tissue regeneration. In this review, we summarize the microenvironmental characteristics of damaged tissues, offer insights into the rationale guiding the design and engineering of microenvironment-sensitive nanozymes, and explore the underlying mechanisms that underpin these nanozymes' responsiveness. This analysis includes their roles in orchestrating cellular signaling, modulating immune responses, and promoting the delicate process of tissue remodeling. Furthermore, we discuss the diverse applications of microenvironment-sensitive nanozymes in tissue regeneration, including bone, soft tissue, and cartilage regeneration. Finally, we shed our sights on envisioning the forthcoming milestones in this field, prospecting a future where microenvironment-sensitive nanozymes contribute significantly to the development of tissue regeneration and improved clinical outcomes.

Photodynamic black phosphorus nanosheets functionalized with polymyxin B for targeted ablation of drug-resistant mixed-species biofilms

Biofilms, particularly those formed by multiple bacterial species, pose significant economic and environmental challenges, especially in the context of medical implants. Addressing the urgent need for effective treatment strategies that do not exacerbate drug resistance, we developed a novel nanoformulation, Ce6&PMb@BPN, based on black phosphorus nanosheets (BPN) for targeted treatment of mixed-species biofilms formed by Acinetobacter baumannii (A. baumannii) and methicillin-resistant Staphylococcus aureus (MRSA).The formulation leverages polymyxin B (PMb) for bacterial targeting and chlorin e6 (Ce6) for photodynamic action. Upon near-infrared (NIR) irradiation, Ce6&PMb@BPN efficiently eliminates biofilms by combining chemotherapy, photodynamic therapy (PDT) and photothermal therapy (PTT), reducing biofilm biomass significantly within 30 min. In vivo studies on mice infected with mixed-species biofilm-coated catheters demonstrated the formulation's potent antibacterial and biofilm ablation effects. Moreover, comprehensive biosafety evaluations confirmed the excellent biocompatibility of Ce6&PMb@BPN. Taken together, this intelligently designed nanoformulation holds potential for effectively treating biofilm-associated infections, addressing the urgent need for strategies to combat antibiotic-resistant biofilms, particularly mixed-species biofilm, in medical settings.

Advancements in magnetic nanoparticle-based biosensors for point-of-care testing

The significance of point-of-care testing (POCT) in early clinical diagnosis and personalized patient care is increasingly recognized as a crucial tool in reducing disease outbreaks and improving patient survival rates. Within the realm of POCT, biosensors utilizing magnetic nanoparticles (MNPs) have emerged as a subject of substantial interest. This review aims to provide a comprehensive evaluation of the current landscape of POCT, emphasizing its growing significance within clinical practice. Subsequently, the current status of the combination of MNPs in the Biological detection has been presented. Furthermore, it delves into the specific domain of MNP-based biosensors, assessing their potential impact on POCT. By combining existing research and spotlighting pivotal discoveries, this review enhances our comprehension of the advancements and promising prospects offered by MNP-based biosensors in the context of POCT. It seeks to facilitate informed decision-making among healthcare professionals and researchers while also promoting further exploration in this promising field of study.

Strategies to Promote the Journey of Nanoparticles Against Biofilm-Associated Infections

Biofilm-associated infections are one of the most challenging healthcare threats for humans, accounting for 80% of bacterial infections, leading to persistent and chronic infections. The conventional antibiotics still face their dilemma of poor therapeutic effects due to the high tolerance and resistance led by bacterial biofilm barriers. Nanotechnology-based antimicrobials, nanoparticles (NPs), are paid attention extensively and considered as promising alternative. This review focuses on the whole journey of NPs against biofilm-associated infections, and to clarify it clearly, the journey is divided into four processes in sequence as 1) Targeting biofilms, 2) Penetrating biofilm barrier, 3) Attaching to bacterial cells, and 4) Translocating through bacterial cell envelope. Through outlining the compositions and properties of biofilms and bacteria cells, recent advances and present the strategies of each process are comprehensively discussed to combat biofilm-associated infections, as well as the combined strategies against these infections with drug resistance, aiming to guide the rational design and facilitate wide application of NPs in biofilm-associated infections.

Biofilm Microenvironment-Sensitive Piezoelectric Nanomotors for Enhanced Penetration and ROS/NO Synergistic Bacterial Elimination

Sonodynamic therapy offers a highly accurate treatment for bacterial infections; however, its antibacterial efficacy is hindered by bacterial biofilms that limit the penetration of sonosensitizers. Herein, a nitric oxide (NO)-driven mushroom-like Janus nanomotor (BT@PDA-La) based on the unilateral coating of polydopamine (PDA) on piezoelectric tetragonal barium titanate (BT) and further modified with l-arginine (l-Arg) on the PDA side is fabricated. In the infected microenvironment with high levels of H2O2, NO is produced unilaterally from BT@PDA-La, thus leading to its self-propelled movement and facilitating its permeability in the biofilm. Under ultrasonic vibrations, the piezoelectric effect of BT@PDA-La is triggered by the exogenous mechanical wave, and toxic reactive oxygen species (ROS) are efficiently generated via an in situ catalytic reaction. The synergistic treatment with ROS/NO achieved the destruction of biofilms and embedded drug-resistant bacteria in vitro. Importantly, BT@PDA-La exhibits excellent biofilm penetration capacity, effectively eliminating biofilm infection while accelerating the healing of infected muscles by alleviating oxidative stress, regulating inflammatory factors, and accelerating angiogenesis. Collectively, this study provides a promising strategy for enhancing the penetration of pathological environment-driven nanomaterials through biofilms and advances the application of nanomotors for the therapy of bacterial infections in clinical medicine.

The Combination of Antibiotic and Non-Antibiotic Compounds Improves Antibiotic Efficacy against Multidrug-Resistant Bacteria

Bacterial antibiotic resistance, especially the emergence of multidrug-resistant (MDR) strains, urgently requires the development of effective treatment strategies. It is always of interest to delve into the mechanisms of resistance to current antibiotics and target them to promote the efficacy of existing antibiotics. In recent years, non-antibiotic compounds have played an important auxiliary role in improving the efficacy of antibiotics and promoting the treatment of drug-resistant bacteria. The combination of non-antibiotic compounds with antibiotics is considered a promising strategy against MDR bacteria. In this review, we first briefly summarize the main resistance mechanisms of current antibiotics. In addition, we propose several strategies to enhance antibiotic action based on resistance mechanisms. Then, the research progress of non-antibiotic compounds that can promote antibiotic-resistant bacteria through different mechanisms in recent years is also summarized. Finally, the development prospects and challenges of these non-antibiotic compounds in combination with antibiotics are discussed.

Recent Advances in Nanozyme-Mediated Strategies for Pathogen Detection and Control

Pathogen detection and control have long presented formidable challenges in the domains of medicine and public health. This review paper underscores the potential of nanozymes as emerging bio-mimetic enzymes that hold promise in effectively tackling these challenges. The key features and advantages of nanozymes are introduced, encompassing their comparable catalytic activity to natural enzymes, enhanced stability and reliability, cost effectiveness, and straightforward preparation methods. Subsequently, the paper delves into the detailed utilization of nanozymes for pathogen detection. This includes their application as biosensors, facilitating rapid and sensitive identification of diverse pathogens, including bacteria, viruses, and plasmodium. Furthermore, the paper explores strategies employing nanozymes for pathogen control, such as the regulation of reactive oxygen species (ROS), HOBr/Cl regulation, and clearance of extracellular DNA to impede pathogen growth and transmission. The review underscores the vast potential of nanozymes in pathogen detection and control through numerous specific examples and case studies. The authors highlight the efficiency, rapidity, and specificity of pathogen detection achieved with nanozymes, employing various strategies. They also demonstrate the feasibility of nanozymes in hindering pathogen growth and transmission. These innovative approaches employing nanozymes are projected to provide novel options for early disease diagnoses, treatment, and prevention. Through a comprehensive discourse on the characteristics and advantages of nanozymes, as well as diverse application approaches, this paper serves as a crucial reference and guide for further research and development in nanozyme technology. The expectation is that such advancements will significantly contribute to enhancing disease control measures and improving public health outcomes.

Exploring the robustness of DNA nanotubes framework for anticancer theranostics toward the 2D/3D clusters of hypopharyngeal respiratory tumor cells

This study aimed to develop a robust approach for the early diagnosis and treatment of tumors. Short circular DNA nanotechnology synthesized a stiff and compact DNA nanotubes (DNA-NTs) framework. TW-37, a small molecular drug, was loaded into DNA-NTs for BH3-mimetic therapy to elevate the intracellular cytochrome-c levels in 2D/3D hypopharyngeal tumor (FaDu) cell clusters. After anti-EGFR functionalization, the DNA-NTs were tethered with a cytochrome-c binding aptamer, which can be applied to evaluate the elevated intracellular cytochrome-c levels via in situ hybridization (FISH) analysis and fluorescence resonance energy transfer (FRET). The results showed that DNA-NTs were enriched within the tumor cells via anti-EGFR targeting with a pH-responsive controlled release of TW-37. In this way, it initiated the triple inhibition of "BH3, Bcl-2, Bcl-xL, and Mcl-1". The triple inhibition of these proteins caused Bax/Bak oligomerization, leading to the perforation of the mitochondrial membrane. This led to the elevation of intracellular cytochrome-c levels, which reacted with the cytochrome-c binding aptamer to produce FRET signals. In this way, we successfully targeted 2D/3D clusters of FaDu tumor cells and achieved the tumor-specific and pH-triggered release of TW-37, causing tumor cell apoptosis. This pilot study suggests that anti-EGFR functionalized, TW-37 loaded, and cytochrome-c binding aptamer tethered DNA-NTs might be the hallmark for early tumor diagnosis and therapy.