Enhanced synergetic antibacterial activity by a reduce graphene oxide/Ag nanocomposite through the photothermal effect

"Antenna Effect"-Enhanced AuNPs@rGO Photothermal Coating Promotes 3D Printing of Osteogenic Active Scaffolds to Repair Bone Defects after Malignant Tumor Surgery

Malignant bone tumor defects are difficult to treat because of the simultaneous need for tumor treatment and bone-repair promotion. This study presents a bioactive composite scaffold (T-rGO@Au) for personalized bone defect repair and bone tumor treatment. The T-rGO@Au scaffold has a porous structure, and its mechanical properties are close to those of human cancellous bone. The T-rGO@Au scaffold can induce upregulation of osteopontin (OPN), RUNX-2, and osteocalcin (OCN) gene expression. In vivo experiments showed that the bone volume/total volume (BV/TV) ratio with the T-rGO@Au scaffold was the highest. The new bone was tightly integrated with the implant, demonstrating effective osseointegration. The T-rGO@Au scaffold locally generated high temperatures and reactive oxygen species under near-infrared excitation, and AuNPs enhanced the photothermal performance of rGO through the "antenna effect." Furthermore, in vitro experiments showed that the tumor cell nuclei were destroyed, late-stage apoptotic cells increased, and cell morphology was severely damaged. Additionally, RNA-seq revealed that tumor cell destruction was mediated through signaling pathways, such as the MAPK pathway. In vivo antitumor experiments also demonstrated that the T-rGO@Au scaffold significantly inhibited the growth of tumor cells within 2 weeks. Thus, the T-rGO@Au scaffold provides a new treatment strategy for the development of implantable scaffolds for bone tumor defects.

Nanomaterials at the forefront of antimicrobial therapy by photodynamic and photothermal strategies

In the face of the increasing resistance of microorganisms to traditional antibiotics, the development of innovative treatment methods is becoming increasingly urgent. Nanophototherapy technology can precisely target the infected area and achieve synergistic antibacterial effects in multiple modes. This phototherapy method has shown significant efficacy in treating diseases caused by drug-resistant bacteria, especially in the elimination of biofilms, where it has demonstrated strong dissolution capabilities. PTT utilizes photothermal agents to convert near-infrared light into heat, effectively killing bacteria and promoting tissue regeneration. Similarly, PDT utilizes photosensitizers, which produce reactive oxygen species (ROS) when activated by light, destroying the structure and function of bacterial cells. This review summarizes photothermal agents and photosensitizers used for antibacterial purposes. In conducting our literature review, we employed a systematic approach to ensure a comprehensive and representative selection of studies. Additionally, this article explores the potential of phototherapy in regulating wound microenvironments, promoting wound healing, and activating the immune system. Nanophototherapeutic materials show great potential for application in antibacterial treatment and are expected to provide innovative solutions for drug-resistant bacterial infections that traditional antibiotics are struggling to address.

Photodynamic therapy of cancer using graphene nanomaterials

INTRODUCTION

High incidence and fatality rates of cancer remain a global challenge. The success of conventional treatment modalities is being questioned on account of adverse effects. Photodynamic therapy (PDT) is a potential alternative. It utilizes a combination of photosensitizer (PS), light and oxygen to target the tissues locally, thereby minimizing the damage to neighboring healthy tissues. Conventional PSs suffer from poor selectivity, high hydrophobicity and sub-optimal yield of active radicals. Graphene nanomaterials (GNs) exhibit interesting particulate and photophysical properties in the context of their use in PDT.

AREA COVERED

We focus on describing the mechanistic aspects of PDT-mediated elimination of cancer cells and the subsequent development of adaptive immunity. After covering up-to-date literature on the significant enhancement of PDT capability with GNs, we have discussed the probability of combining PDT with chemo-, immuno-, and photothermal therapy to make the treatment more effective.

EXPERT OPINION

GNs can be synthesized in various size ranges, and their biocompatibility can be improved through surface functionalization and doping. These can be used as PS to generate ROS or conjugated with other PS molecules for treating deep-seated tumors. With increasing evidence on biosafety, such materials offer hope as antitumor therapeutics.

Engineering Ag-Decorated Graphene Oxide Nano-Photothermal Platforms with Enhanced Antibacterial Properties for Promoting Infectious Wound Healing

Introduction

Graphene oxide (GO) nanoparticles have emerged as a compelling photothermal agent (PHTA) in the realm of photothermal antibacterial therapy, owing to their cost-effectiveness, facile synthesis, and remarkable photostability. Nevertheless, the therapeutic efficacy of GO nanoparticles is commonly hindered by their inherent drawback of low photothermal conversion efficiency (PCE).

Methods

Herein, we engineer the Ag/GO-GelMA platform by growing the Ag on the surface of GO and encapsulating the Ag/GO nanoparticles into the GelMA hydrogels.

Results

The resulting Ag/GO-GelMA platform demonstrates a significantly enhanced PCE (47.6%), surpassing that of pure GO (11.8%) by more than fourfold. As expected, the Ag/GO-GelMA platform, which was designed to integrate the benefits of Ag/GO nanoparticles (high PCE) and hydrogel (slowly releasing Ag+ to exert an inherent antibacterial effect), has been shown to exhibit exceptional antibacterial efficacy. Furthermore, transcriptome analyses demonstrated that the Ag/GO-GelMA platform could significantly down-regulate pathways linked to inflammation (the MAPK and PI3K-Akt pathways) and had the ability to promote cell migration.

Discussion

Taken together, this study presents the design of a potent photothermal antibacterial platform (Ag/GO-GelMA) aimed at enhancing the healing of infectious wounds. The platform utilizes a handy method to enhance the PCE of GO, thereby making notable progress in the utilization of GO nano-PHTAs.

Unveiling Xanthine Presence in Rohu Fish Using Ag+-Doped MoS2 Nanosheets Through Electrochemical Analysis

Here, we envisage the development of the rapid, reliable, and facile electrochemical sensor for the primary detection of xanthine (Xn) which is significant for the food quality measurement, based on the silver-doped molybdenum disulfide (Ag@MoS2) nanosheets. The structural and compositional properties of the prepared samples were tested through X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and X-ray photon spectroscopy (XPS). The two-dimensional (2D) MoS2 nanosheets provide the large surface area for the sensing applications and the silver ions help in the enhanced electrochemical response. The fabricated enzymatic biosensor exhibits magnificent cyclic stability with a limit of detection of 27 nM. Also, the sensor was tested for rapid, reproducible, specific, and regenerable up to 10 cycles and has a shelf life of 2 weeks. The outcomes of this study suggest that the proposed matrix could be employed for the fabrication of devices for early detection of xanthine.

Silver and Carbon Nanomaterials/Nanocomplexes as Safe and Effective ACE2-S Binding Blockers on Human Skin Cell Lines

(1) Background: Angiotensin-converting enzyme 2 (ACE2) is a crucial functional receptor of the SARS-CoV-2 virus. Although the scale of infections is no longer at pandemic levels, there are still fatal cases. The potential of the virus to infect the skin raises questions about new preventive measures. In the context of anti-SARS-CoV-2 applications, the interactions of antimicrobial nanomaterials (silver, Ag; diamond, D; graphene oxide, GO and their complexes) were examined to assess their ability to affect whether ACE2 binds with the virus. (2) Methods: ACE2 inhibition competitive tests and in vitro treatments of primary human adult epidermal keratinocytes (HEKa) and primary human adult dermal fibroblasts (HDFa) were performed to assess the blocking capacity of nanomaterials/nanocomplexes and their toxicity to cells. (3) Results: The nanocomplexes exerted a synergistic effect compared to individual nanomaterials. HEKa cells were more sensitive than HDFa cells to Ag treatments and high concentrations of GO. Cytotoxic effects were not observed with D. In the complexes, both carbonic nanomaterials had a soothing effect against Ag. (4) Conclusions: The Ag5D10 and Ag5GO10 nanocomplexes seem to be most effective and safe for skin applications to combat SARS-CoV-2 infection by blocking ACE2-S binding. These nanocomplexes should be evaluated through prolonged in vivo exposure. The expected low specificity enables wider applications.

Cell Wall Binding Strategies Based on Cu3SbS3 Nanoparticles for Selective Bacterial Elimination and Promotion of Infected Wound Healing

Utilizing nanomaterials as an alternative to antibiotics, with a focus on maintaining high biosafety, has emerged as a promising strategy to combat antibiotic resistance. Nevertheless, the challenge lies in the indiscriminate attack of nanomaterials on both bacterial and mammalian cells, which limits their practicality. Herein, Cu3SbS3 nanoparticles (NPs) capable of generating reactive oxygen species (ROS) are discovered to selectively adsorb and eliminate bacteria without causing obvious harm to mammalian cells, thanks to the interaction between O of N-acetylmuramic acid in bacterial cell walls and Cu of the NPs. Coupled with the short diffusion distance of ROS in the surrounding medium, a selective antibacterial effect is achieved. Additionally, the antibacterial mechanism is then identified: Cu3SbS3 NPs catalyze the generation of O2•-, which has subsequently been conversed by superoxide dismutase to H2O2. The latter is secondary catalyzed by the NPs to form •OH and 1O2, initiating an in situ attack on bacteria. This process depletes bacterial glutathione in conjunction with the disruption of the antioxidant defense system of bacteria. Notably, Cu3SbS3 NPs are demonstrated to efficiently impede biofilm formation; thus, a healing of MRSA-infected wounds was promoted. The bacterial cell wall-binding nanoantibacterial agents can be widely expanded through diversified design.

Iron-Reduced Graphene Oxide Core-Shell Micromotors Designed for Magnetic Guidance and Photothermal Therapy under Second Near-Infrared Light

Core-shell micro/nanomotors have garnered significant interest in biomedicine owing to their versatile task-performing capabilities. However, their effectiveness for photothermal therapy (PTT) still faces challenges because of their poor tumor accumulation, lower light-to-heat conversion, and due to the limited penetration of near-infrared (NIR) light. In this study, we present a novel core-shell micromotor that combines magnetic and photothermal properties. It is synthesized via the template-assisted electrodeposition of iron (Fe) and reduced graphene oxide (rGO) on a microtubular pore-shaped membrane. The resulting Fe-rGO micromotor consists of a core of oval-shaped zero-valent iron nanoparticles with large magnetization. At the same time, the outer layer has a uniform reduced graphene oxide (rGO) topography. Combined, these Fe-rGO core-shell micromotors respond to magnetic forces and near-infrared (NIR) light (1064 nm), achieving a remarkable photothermal conversion efficiency of 78% at a concentration of 434 µg mL-1. They can also carry doxorubicin (DOX) and rapidly release it upon NIR irradiation. Additionally, preliminary results regarding the biocompatibility of these micromotors through in vitro tests on a 3D breast cancer model demonstrate low cytotoxicity and strong accumulation. These promising results suggest that such Fe-rGO core-shell micromotors could hold great potential for combined photothermal therapy.

Functional nanomaterials as photosensitizers or delivery systems for antibacterial photodynamic therapy

Bacterial infection is a global health problem that closely related to various diseases threatening human life. Although antibiotic therapy has been the mainstream treatment method for various bacterial infectious diseases for decades, the increasing emergence of bacterial drug resistance has brought enormous challenges to the application of antibiotics. Therefore, developing novel antibacterial strategies is of great importance. By producing reactive oxygen species (ROS) with photosensitizers (PSs) under light irradiation, antibacterial photodynamic therapy (aPDT) has emerged as a non-invasive and promising approach for treating bacterial infections without causing drug resistance. However, the insufficient therapeutic penetration, poor hydrophilicity, and poor biocompatibility of traditional PSs greatly limit the efficacy of aPDT. Recently, studies have found that nanomaterials with characteristics of favorable photocatalytic activity, surface plasmonic resonance, easy modification, and high drug loading capacity can improve the therapeutic efficacy of aPDT. In this review, we aim to provide a comprehensive understanding of the mechanism of nanomaterials-mediated aPDT and summarize the representative nanomaterials in aPDT, either as PSs or carriers for PSs. In addition, the combination of advanced nanomaterials-mediated aPDT with other therapies, including targeted therapy, gas therapy, and multidrug resistance (MDR) therapy, is reviewed. Also, the concerns and possible solutions of nanomaterials-based aPDT are discussed. Overall, this review may provide theoretical basis and inspiration for the development of nanomaterials-based aPDT.

2D Nanomaterials and Their Drug Conjugates for Phototherapy and Magnetic Hyperthermia Therapy of Cancer and Infections

Photothermal therapy (PTT) and magnetic hyperthermia therapy (MHT) using 2D nanomaterials (2DnMat) have recently emerged as promising alternative treatments for cancer and bacterial infections, both important global health challenges. The present review intends to provide not only a comprehensive overview, but also an integrative approach of the state-of-the-art knowledge on 2DnMat for PTT and MHT of cancer and infections. High surface area, high extinction coefficient in near-infra-red (NIR) region, responsiveness to external stimuli like magnetic fields, and the endless possibilities of surface functionalization, make 2DnMat ideal platforms for PTT and MHT. Most of these materials are biocompatible with mammalian cells, presenting some cytotoxicity against bacteria. However, each material must be comprehensively characterized physiochemically and biologically, since small variations can have significant biological impact. Highly efficient and selective in vitro and in vivo PTTs for the treatment of cancer and infections are reported, using a wide range of 2DnMat concentrations and incubation times. MHT is described to be more effective against bacterial infections than against cancer therapy. Despite the promising results attained, some challenges remain, such as improving 2DnMat conjugation with drugs, understanding their in vivo biodegradation, and refining the evaluation criteria to measure PTT or MHT effects.

Bioinspired silver nanoparticle-based nanocomposites for effective control of plant pathogens: A review

Plant pathogens, including bacteria, fungi, and viruses, pose significant challenges to the farming community due to their extensive diversity, the rapidly evolving phenomenon of multi-drug resistance (MDR), and the limited availability of effective control measures. Amid mounting global pressure, particularly from the World Health Organization, to limit the use of antibiotics in agriculture and livestock management, there is increasing consideration of engineered nanomaterials (ENMs) as promising alternatives for antimicrobial applications. Studies focusing on the application of ENMs in the fight against MDR pathogens are receiving increasing attention, driven by significant losses in agriculture and critical knowledge gaps in this crucial field. In this review, we explore the potential contributions of silver nanoparticles (AgNPs) and their nanocomposites in combating plant diseases, within the emerging interdisciplinary arena of nano-phytopathology. AgNPs and their nanocomposites are increasingly acknowledged as promising countermeasures against plant pathogens, owing to their unique physicochemical characteristics and inherent antimicrobial properties. This review explores recent advancements in engineered nanocomposites, highlights their diverse mechanisms for pathogen control, and draws attention to their potential in antibacterial, antifungal, and antiviral applications. In the discussion, we briefly address three crucial dimensions of combating plant pathogens: green synthesis approaches, toxicity-environmental concerns, and factors influencing antimicrobial efficacy. Finally, we outline recent advancements, existing challenges, and prospects in scholarly research to facilitate the integration of nanotechnology across interdisciplinary fields for more effective treatment and prevention of plant diseases.

Interaction of 2D nanomaterial with cellular barrier: Membrane attachment and intracellular trafficking

The cell membrane serves as a barrier against the free entry of foreign substances into the cell. Limited by factors such as solubility and targeting, it is difficult for some drugs to pass through the cell membrane barrier and exert the expected therapeutic effect. Two-dimensional nanomaterial (2D NM) has the advantages of high drug loading capacity, flexible modification, and multimodal combination therapy, making them a novel drug delivery vehicle for drug membrane attachment and intracellular transport. By modulating the surface properties of nanocarriers, it is capable of carrying drugs to break through the cell membrane barrier and achieve precise treatment. In this review, we review the classification of various common 2D NMs, the primary parameters affecting their adhesion to cell membranes, and the uptake mechanisms of intracellular transport. Furthermore, we discuss the therapeutic potential of 2D NMs for several major disorders. We anticipate this review will deepen researchers' understanding of the interaction of 2D NM drug carriers with cell membrane barriers, and provide insights for the subsequent development of novel intelligent nanomaterials capable of intracellular transport.

Progress in the application of graphene and its derivatives to osteogenesis

As bone and joint injuries from various causes become increasingly prominent, how to effectively reconstruct and repair bone defects presents a difficult problem for clinicians and researchers. In recent years, graphene and its derivatives have been the subject of growing body of research and have been found to promote the proliferation and osteogenic differentiation of stem cells. This provides a new idea for solving the clinical problem of bone defects. However, as as numerous articles address various aspects and have not been fully systematized, there is an urgent need to classify and summarize them. In this paper, for the first time, the effects of graphene and its derivatives on stem cells in solution, in 2D and 3D structures and in vivo and their possible mechanisms are reviewed, and the cytotoxic effects of graphene and its derivatives were summarized and analyzed. The toxicity of graphene and its derivatives is further reviewed. In addition, we suggest possible future development directions of graphene and its derivatives in bone tissue engineering applications to provide a reference for further clinical application.

Hollow Cobalt Sulfide Nanospheres with Highly Enzyme-like Antibacterial Activities to Accelerate Infected Wound Healing

The emergence of nanozymes presents a promising alternative to antibiotics for reactive oxygen species-mediated broad-spectrum antimicrobial purposes, but nanozymes still face challenges of low therapeutic efficiency and poor biocompatibility. Herein, we creatively prepared a novel kind of hollow cobalt sulfide (CoS) nanospheres with a unique mesoporous structure that is able to provide numerous active sites for enzyme-like reactions. The results revealed that 50 μg/mL of CoS nanospheres exhibited strong peroxidase- and oxidase-like activities under physiological conditions with the assistance of a low concentration of hydrogen peroxide (H2O2, 100 μM) while possessing highly efficient GSH-depletion ability, which endowed CoS nanospheres with triple enzyme-like properties to combat bacterial infections. The in vitro experiments demonstrated that the CoS nanozyme displayed significant antibacterial effects against both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli). The in vivo implantation showed that the synthesized CoS effectively eliminated bacteria and promoted the recovery of infected wounds in rats while exhibiting a low cytotoxicity. This study provides a promising treatment strategy to accelerate infected wound healing.

Recent advances in nanomaterial-mediated bacterial molecular action and their applications in wound therapy

Because of the multi-pathway antibacterial mechanisms of nanomaterials, they have received widespread attention in wound therapy. However, owing to the complexities of bacterial responses toward nanomaterials, antibacterial molecular mechanisms remain unclear, making it difficult to rationally design highly efficient antibacterial nanomaterials. Fortunately, molecular dynamics simulations and omics techniques have been used as effective methods to further investigate the action targets of nanomaterials. Therefore, the review comprehensively analyzes the antibacterial mechanisms of nanomaterials from the morphology-dependent antibacterial activity and physicochemical/optical properties-dependent antibacterial activity, which provided guidance for constructing excellently efficient and broad-spectrum antibacterial nanomaterials for wound therapy. More importantly, the main molecular action targets of nanomaterials from the membranes, DNA, energy metabolism pathways, oxidative stress defense systems, ribosomes, and biofilms are elaborated in detail. Furthermore, nanomaterials used in wound therapy are reviewed and discussed. Finally, future directions of nanomaterials from mechanisms to nanomedicine are further proposed.

Polyethylene glycol modified graphene oxide-silver nanoparticles nanocomposite as a novel antibacterial material with high stability and activity

Inorganic antibacterial nanomaterials play an increasingly important role in addressing the growing threat of drug-resistant bacteria. Graphene oxide-silver nanoparticles composite (GO-AgNPs), as a kind of inorganic nanomaterials, have excellent antibacterial properties, showing promising potential in biomedical field. However, GO-AgNPs are terribly prone to sedimentation due to aggregation in physiological solutions, along with its non-environmental issues during the synthesis process, seriously limits the antibacterial application of GO-AgNPs in the biomedical field. To solve this problem, herein, polyethylene glycol-graphene oxide-silver nanoparticles composite (GO-AgNPs-PEG) were prepared by modifying GO-AgNPs with polyethylene glycol to enhance their dispersion stability in physiological solutions. In addition, GO-AgNPs-PEG were prepared with using the natural product gallic acid as a reductant and stabilizer, exhibiting the characteristic of environmentally friendly. Meanwhile, the dispersion stability and antibacterial activity of GO-AgNPs-PEG were characterized by various technical methods, it was found that GO-AgNPs-PEG can be stably dispersed in a variety of physiological solutions (e.g., physiological saline, phosphate buffer solution, Luria-Bertani medium, Murashige and Skoog medium) for more than one week. Moreover, the antibacterial properties of GO-AgNPs-PEG in physiological solutions were significantly better than those of GO-AgNPs. Furthermore, it was discovered that the antibacterial mechanism of GO-AgNPs-PEG was probably associated to destroying the integrity of bacterial cell walls and membranes. The findings in this work can provide new ideas and references for the development of new inorganic antibacterial nanomaterials with stable dispersion in physiological solutions.

Recent advances on hyperthermia therapy applications of carbon-based nanocomposites

Generally, hyperthermia is referred to the composites capability to increase local temperature in such a way that the generated heat would lead to cancerous or bacteria cells destruction, with minimum damage to normal tissue cells. Many different materials have been utilized for hyperthermia application via different heat generating methods. Carbon-based nanomaterials consisting of graphene oxide (GO), carbon nanotube (CNT), carbon dot (CD) and carbon quantum dot (CQD), nanodiamond (ND), fullerene and carbon fiber (CF), have been studied significantly for different applications including hyperthermia due to their biocompatibility, biodegradability, chemical and physical stability, thermal and electrical conductivity and in some cases photothermal conversion. Therefore, in this comprehensive review, a structure-based view on carbon nanomaterials application in hyperthermia therapy of cancer and bacteria via various methods such as optical, magnetic, ultrasonic and radiofrequency-induced hyperthermia is presented.

Trends in Photothermal Nanostructures for Antimicrobial Applications

The rapid development of antimicrobial resistance due to broad antibiotic utilisation in the healthcare and food industries and the non-availability of novel antibiotics represents one of the most critical public health issues worldwide. Current advances in nanotechnology allow new materials to address drug-resistant bacterial infections in specific, focused, and biologically safe ways. The unique physicochemical properties, biocompatibility, and wide range of adaptability of nanomaterials that exhibit photothermal capability can be employed to develop the next generation of photothermally induced controllable hyperthermia as antibacterial nanoplatforms. Here, we review the current state of the art in different functional classes of photothermal antibacterial nanomaterials and strategies to optimise antimicrobial efficiency. The recent achievements and trends in developing photothermally active nanostructures, including plasmonic metals, semiconductors, and carbon-based and organic photothermal polymers, and antibacterial mechanisms of action, including anti-multidrug-resistant bacteria and biofilm removal, will be discussed. Insights into the mechanisms of the photothermal effect and various factors influencing photothermal antimicrobial performance, emphasising the structure-performance relationship, are discussed. We will examine the photothermal agents' functionalisation for specific bacteria, the effects of the near-infrared light irradiation spectrum, and active photothermal materials for multimodal synergistic-based therapies to minimise side effects and maintain low costs. The most relevant applications are presented, such as antibiofilm formation, biofilm penetration or ablation, and nanomaterial-based infected wound therapy. Practical antibacterial applications employing photothermal antimicrobial agents, alone or in synergistic combination with other nanomaterials, are considered. Existing challenges and limitations in photothermal antimicrobial therapy and future perspectives are presented from the structural, functional, safety, and clinical potential points of view.

Recent advances in modification of novel carbon-based composites: Synthesis, properties, and biotechnological/ biomedical applications

Nowadays, carbon-based materials owing to great interest in biomedical science/biotechnology and applied for effective diagnosis and treatment of disease. To enhance the effectiveness of carbon nanotubes (CNTs)/graphene-based materials for bio-medical science/technology applications, different kinds of surface modification/functionalization were developed for the attachment of metal oxides nanostructures, biomolecules and polymers. The attachment of pharmaceutical agents with CNTs/graphene, make it a favorable candidate in research field of bio-medical science/technology applications. Surface modified/functionalized CNTs and graphene derivatives materials integrated with pharmaceutical agents has been developed for the purpose of cancer therapy, antibacterial action, pathogens bio detection, drug and gene delivery. Surface modification or functionalization of CNT/graphene materials provides good platform for pharmaceutical agents attachment with improved surface Raman scattering, fluorescence and its quenching capability. Graphene-based biosensing and bioimaging technologies are widely applied to identify numerous trace level analytes. These fluorescent and electrochemical sensors are utilized primarily for detecting organic, inorganic, and biomolecules. In this article, we highlights and summarized overview of the current research progress concerned on the CNTs/graphene-based materials as a new generation materials for detection and treatment of diseases.

Graphene in nanomedicine: A review on nano-bio factors and antibacterial activity

Graphene-based nanomaterials possess potent antibacterial activity and have engrossed immense interest among researchers as an active armour against pathogenic microbes. A comprehensive perception of the antibacterial activity of these nanomaterials is critical to the fabrication of highly effective antimicrobial nanomaterials, which results in highly efficient and enhanced activity. These materials owing to their antimicrobial activity are utilized as nanomedicine against various pathogenic microbes. The present article reviews the antimicrobial activity of graphene and its analogs such as graphene oxide, reduced graphene oxide as well as metal, metal oxide and polymeric composites. The review draws emphasis on the effect of various nano-bio factors on the antibacterial capability. It also provides an insight into the antibacterial properties of these materials along with a brief discussion on the discrepancies in their activities as evidenced by the scientific communities. In this way, the review is expected to shed light on future research and development in graphene-based nanomedicine.

Magnesium Ortho-Vanadate/Magnesium Oxide/Graphene Oxide Embedded through Cellulose Acetate-Based Films for Wound Healing Applications

A multifunctional nano-films of cellulose acetate (CA)/magnesium ortho-vanadate (MOV)/magnesium oxide/graphene oxide wound coverage was fabricated. Through fabrication, different weights of the previously mentioned ingredients were selected to receive a certain morphological appearance. The composition was confirmed by XRD, FTIR, and EDX techniques. SEM micrograph of Mg₃(VO₄)₂/MgO/GO@CA film depicted that there was a porous surface with flattened rounded MgO grains with an average size of 0.31 µm was observed. Regarding wettability, the binary composition of Mg₃(VO₄)₂@CA occupied the lowest contact angle of 30.15 ± 0.8^o, while pure CA represents the highest one at 47.35 ± 0.4°. The cell viability % amongst the usage of 4.9 µg/mL of Mg₃(VO₄)₂/MgO/GO@CA is 95.77 ± 3.2%, while 2.4 µg/mL showed 101.54 ± 2.9%. The higher concentration of 5000 µg/mL exhibited a viability of 19.23%. According to optical results, the refractive index jumped from 1.73 for CA to 1.81 for Mg₃(VO₄)₂/MgO/GO@CA film. The thermogravimetric analysis showed three main stages of degradation. The initial temperature started from room temperature to 289 °C with a weight loss of 13%. On the other hand, the second stage started from the final temperature of the first stage and end at 375 °C with a weight loss of 52%. Finally, the last stage was from 375 to 472 °C with 19% weight loss. The obtained results, such as high hydrophilic behavior, high cell viability, surface roughness, and porosity due to the addition of nanoparticles to the CA membrane, all played a significant role in enhancing the biocompatibility and biological activity of the CA membrane. The enhancements in the CA membrane suggest that it can be utilized in drug delivery and wound healing applications.

Identification of circular RNAs expression pattern in caprine fetal fibroblast cells exposed to a chronic non-cytotoxic dose of graphene oxide-silver nanoparticle nanocomposites

The widespread use of graphene oxide-silver nanoparticle nanocomposites (GO-AgNPs) in biomedical sciences is increasing the chances of human and animal exposure to its chronic non-toxic doses. Exposure to AgNPs-related nanomaterials may result in the negative effect on the dam, fetus and offspring. However, there are only little available information for profound understanding of the epigenetic alteration in the cells and animals caused by low-dose chronic exposure of GO-AgNPs. The present study investigated the effect of 0.5 μg/mL GO-AgNPs for 10 weeks on the differential expression of circular RNAs (circRNAs) in caprine fetal fibroblast cells (CFFCs), and this dose of GO-AgNPs did not affect cell viability and ROS level. We predicted the functions of those differentially expressed (DE) circRNAs in CFFCs by bioinformatics analysis. Furthermore, we validated the expression of ten DE circRNAs using quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) to ensure the reliability of the sequencing data. Our results showed that the DE circRNAs may potentially regulate the GO-AgNPs-inducing epigenetic toxicity through a regulatory network consisted of circRNAs, miRNAs and messenger RNAs (mRNAs). Therefore, the epigenetics toxicity is essential to assess the biosafety level of GO-AgNPs.

Photo-Antibacterial Activity of Two-Dimensional (2D)-Based Hybrid Materials: Effective Treatment Strategy for Controlling Bacterial Infection

Bacterial contamination in water bodies is a severe scourge that affects human health and causes mortality and morbidity. Researchers continue to develop next-generation materials for controlling bacterial infections from water. Photo-antibacterial activity continues to gain the interest of researchers due to its adequate, rapid, and antibiotic-free process. Photo-antibacterial materials do not have any side effects and have a minimal chance of developing bacterial resistance due to their rapid efficacy. Photocatalytic two-dimensional nanomaterials (2D-NMs) have great potential for the control of bacterial infection due to their exceptional properties, such as high surface area, tunable band gap, specific structure, and tunable surface functional groups. Moreover, the optical and electric properties of 2D-NMs might be tuned by creating heterojunctions or by the doping of metals/carbon/polymers, subsequently enhancing their photo-antibacterial ability. This review article focuses on the synthesis of 2D-NM-based hybrid materials, the effect of dopants in 2D-NMs, and their photo-antibacterial application. We also discuss how we could improve photo-antibacterials by using different strategies and the role of artificial intelligence (AI) in the photocatalyst and in the degradation of pollutants. Finally, we discuss was of improving the photo-antibacterial activity of 2D-NMs, the toxicity mechanism, and their challenges.

Wound dressing based on PVA nanofiber containing silk fibroin modified with GO/ZnO nanoparticles for superficial wound healing: In vitro and in vivo evaluations

Silk fibroin (SF), extracted from Bombyx mori, has unique physicochemical properties to achieve an efficient wound dressing. In this study, reduced graphene oxide (RGO)/ZnO NPs/silk fibroin nanocomposite was made, and an innovative nanofiber of SF/polyvinyl alcohol (PVA)/RGO/ZnO NPs was ready with the electrospinning technique and successfully characterized. The results of MIC and OD analyses were used to investigate the synthesized materials' antibacterial effects and displayed that the synthesized materials could inhibit growth against Staphylococcus aureus and Escherichia coli bacteria. However, both in vitro cytotoxicity (MTT) and scratch wound studies have shown that RGO/ZnO NPs and SF/PVA/RGO/ZnO NPs are not only non-toxic to NIH 3T3 fibroblasts, but also can cause cell viability, cell proliferation, and cell migration. Furthermore, improving the synthesized nanofiber's structural properties in the presence of RGO and ZnO NPs has been confirmed by performing tensile strength, contact angle, and biodegradation analyses. Also, in a cell attachment analysis, fibroblast cells had migrated and expanded well in the nanofibrous structures. Moreover, in vivo assay, SF/PVA/RGO/ZnO NPs nanofiber treated rats and has been shown significant healing activity and tissue regeneration compared with other treated groups. Therefore, this study suggests that SF/PVA/RGO/ZnO NPs nanofiber is a hopeful wound dressing for preventing bacteria growth and improving superficial wound repair.

Multimodal Imaging and Phototherapy of Cancer and Bacterial Infection by Graphene and Related Nanocomposites

The advancements in nanotechnology and nanomedicine are projected to solve many glitches in medicine, especially in the fields of cancer and infectious diseases, which are ranked in the top five most dangerous deadly diseases worldwide by the WHO. There is great concern to eradicate these problems with accurate diagnosis and therapies. Among many developed therapeutic models, near infra-red mediated phototherapy is a non-invasive technique used to invade many persistent tumors and bacterial infections with less inflammation compared with traditional therapeutic models such as radiation therapy, chemotherapy, and surgeries. Herein, we firstly summarize the up-to-date research on graphene phototheranostics for a better understanding of this field of research. We discuss the preparation and functionalization of graphene nanomaterials with various biocompatible components, such as metals, metal oxides, polymers, photosensitizers, and drugs, through covalent and noncovalent approaches. The multifunctional nanographene is used to diagnose the disease with confocal laser scanning microscopy, magnetic resonance imaging computed tomography, positron emission tomography, photoacoustic imaging, Raman, and ToF-SMIS to visualize inside the biological system for imaging-guided therapy are discussed. Further, treatment of disease by photothermal and photodynamic therapies against different cancers and bacterial infections are carefully conferred herein along with challenges and future perspectives.

Graphene-based nanomaterials for cancer therapy and anti-infections

Graphene-based nanomaterials (GBNMs) has been thoroughly investigated and extensively used in many biomedical fields, especially cancer therapy and bacteria-induced infectious diseases treatment, which have attracted more and more attentions due to the improved therapeutic efficacy and reduced reverse effect. GBNMs, as classic two-dimensional (2D) nanomaterials, have unique structure and excellent physicochemical properties, exhibiting tremendous potential in cancer therapy and bacteria-induced infectious diseases treatment. In this review, we first introduced the recent advances in development of GBNMs and GBNMs-based treatment strategies for cancer, including photothermal therapy (PTT), photodynamic therapy (PDT) and multiple combination therapies. Then, we surveyed the research progress of applications of GBNMs in anti-infection such as antimicrobial resistance, wound healing and removal of biofilm. The mechanism of GBNMs was also expounded. Finally, we concluded and discussed the advantages, challenges/limitations and perspective about the development of GBNMs and GBNMs-based therapies. Collectively, we think that GBNMs could be potential in clinic to promote the improvement of cancer therapy and infections treatment.

Metal organic framework-based antibacterial agents and their underlying mechanisms

Bacteria, as the most abundant living organisms, have always been a threat to human life until the development of antibiotics. However, with the wide use of antibiotics over a long time, bacteria have gradually gained tolerance to antibiotics, further aggravating threat to human beings and environmental safety significantly. In recent decades, new bacteria-killing methods based on metal ions, hyperthermia, free radicals, physical pricks, and the coordination of several multi-mechanisms have attracted increasing attention. Consequently, multiple types of new antibacterial agents have been developed. Among them, metal organic frameworks (MOFs) appear to play an increasingly important role. The unique characteristics of MOFs make them suitable multiple-functional platforms. By selecting the appropriate metastable coordination bonds, MOFs can act as reservoirs and release antibacterial metal ions or organic linkers; by constructing a porous structure, MOFs can act as carriers for multiple types of agents and achieve slow and sustained release; and by designing their composition and the pore structure precisely, MOFs can be endowed with properties to produce heat and free radicals under stimulation. Importantly, in combination with other materials, MOFs can act as a platform to kill bacteria effectively through the synergistic effect of multiple types of mechanisms. In this review, we focus on the recent development of MOF-based antibacterial agents, which are classified according to their antibacterial mechanisms.

Silver nanoparticles decorated reduced graphene oxide: Eco-friendly synthesis, characterization, biological activities and embryo toxicity studies

This study was aimed on the eco-friendly synthesis of silver nanoparticles (AgNPs), reduced graphene oxide (rGO) and AgNPs decorated rGO (rGO/AgNPs) nanocomposite and appraisal of their bioactivities and toxicity. As-prepared nanomaterials were established through high resolution X-ray diffraction (HR-XRD), high resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, UV-Vis. spectroscopy and Fourier transform infrared spectroscopy (FT-IR). In this study, leaves extract, graphene oxide (GO) and rGO did not show antibacterial and anticancer activities; no significant embryo toxicity was recorded. On the other hand, AgNPs displayed good antibacterial and anticancer activities; however, higher toxic effects were observed even at the lowest test concentration (0.7 μg/ml). In case of rGO/AgNPs nanocomposite, significant antibacterial activity together with low cytotoxicity was noticed. Interestingly, the embryo toxicity of AgNPs was significantly reduced by rGO, implying the biocompatible nature of as-synthesized nanocomposite. Taken together, these results clearly suggest that rGO/AgNPs nano hybrid composite could be developed as the promising biomaterial for future biomedical applications.

Functionalized injectable hyaluronic acid hydrogel with antioxidative and photothermal antibacterial activity for infected wound healing

Infected wound healing has always been a challenge in clinic. Effective and economic wound dressings with combined antibacterial activity and pro-healing function are highly desirable, especially in the context of infected wounds. An obvious advantage of antibacterial wound dressing is to avoid the overuse of antibiotics and the occurrence of drug resistance. Herein, an injectable hyaluronic acid hydrogel with antioxidative and photothermal antibacterial activity as a functional dressing was prepared, characterized and evaluated in an experimental infected wound model. This hydrogel was developed by loading graphene oxide (GO) in a natural polymer network consisting of hyaluronic acid grafted with tyramine (HT) and gelatin grafted with gallic acid (GGA). The HT/GGA/GO hydrogels have a porous cross-linked network structure and demonstrate a good stability, biocompatibility, antioxidant, hemostatic and photothermal antibacterial activity against Escherichia coli and Staphylococcus aureus. In addition, in vivo studies have shown that HT₁/GGA₂/GO_0.1 hydrogel dressing combined with photothermal therapy can effectively prevent early infection and accelerate wound healing. These results indicated this functionalized injectable hydrogel HT₁/GGA₂/GO_0.1 has a great potential in wound dressing application.

Nanocomposites based on the graphene family for food packaging: historical perspective, preparation methods, and properties

Nanotechnology experienced a great technological advance after the discovery of the graphene family (graphene - Gr, graphene oxide - GO, and reduced graphene oxide-rGO). Based on the excellent properties of these materials, it is possible to develop novel polymeric nanocomposites for several applications in our daily routine. One of the most prominent applications is for food packaging, offering nanocomposites with improved thermal, mechanical, anti-microbial, and barrier properties against gas and water vapor. This paper reviewed food packaging from its inception to the present day, with the development of more resistant and intelligent packaging. Herein, the most common combinations of polymeric matrices (derived from non-renewable and renewable sources) with Gr, GO, and rGO and their typical preparation methods are presented. Besides, the interactions present in these nanocomposites will be discussed in detail, and their final properties will be thoroughly analyzed as a function of the preparation technique and graphene family-matrix combinations.

Combating Drug-Resistant Bacteria Using Photothermally Active Nanomaterials: A Perspective Review

Injudicious use of antibiotics has been the main driver of severe bacterial non-susceptibility to commonly available antibiotics (known as drug resistance or antimicrobial resistance), a global threat to human health and healthcare. There is an increase in the incidence and levels of resistance to antibacterial drugs not only in nosocomial settings but also in community ones. The drying pipeline of new and effective antibiotics has further worsened the situation and is leading to a potentially "post-antibiotic era." This requires novel and effective therapies and therapeutic agents for combating drug-resistant pathogenic microbes. Nanomaterials are emerging as potent antimicrobial agents with both bactericidal and potentiating effects reported against drug-resistant microbes. Among them, the photothermally active nanomaterials (PANs) are gaining attention for their broad-spectrum antibacterial potencies driven mainly by the photothermal effect, which is characterized by the conversion of absorbed photon energy into heat energy by the PANs. The current review capitalizes on the importance of using PANs as an effective approach for overcoming bacterial resistance to drugs. Various PANs leveraging broad-spectrum therapeutic antibacterial (both bactericidal and synergistic) potentials against drug-resistant pathogens have been discussed. The review also provides deeper mechanistic insights into the mechanisms of the action of PANs against a variety of drug-resistant pathogens with a critical evaluation of efflux pumps, cell membrane permeability, biofilm, and quorum sensing inhibition. We also discuss the use of PANs as drug carriers. This review also discusses possible cytotoxicities related to the therapeutic use of PANs and effective strategies to overcome this. Recent developments, success stories, challenges, and prospects are also presented.

2D materials for bone therapy

Due to their prominent physicochemical properties, 2D materials are broadly applied in biomedicine. Currently, 2D materials have achieved great success in treating many diseases such as cancer and tissue engineering as well as bone therapy. Based on their different characteristics, 2D materials could function in various ways in different bone diseases. Herein, the application of 2D materials in bone tissue engineering, joint lubrication, infection of orthopedic implants, bone tumors, and osteoarthritis are firstly reviewed comprehensively together. Meanwhile, different mechanisms by which 2D materials function in each disease reviewed below are also reviewed in detail, which in turn reveals the versatile functions and application of 2D materials. At last, the outlook on how to further broaden applications of 2D materials in bone therapies based on their excellent properties is also discussed.

Smart nanomaterial and nanocomposite with advanced agrochemical activities

Conventional agriculture solely depends upon highly chemical compounds that have negatively ill-affected the health of every living being and the entire ecosystem. Thus, the smart delivery of desired components in a sustainable manner to crop plants is the primary need to maintain soil health in the upcoming years. The premature loss of growth-promoting ingredients and their extended degradation in the soil increases the demand for reliable novel techniques. In this regard, nanotechnology has offered to revolutionize the agrotechnological area that has the imminent potential over conventional agriculture and helps to reform resilient cropping systems withholding prominent food security for the ever-growing world population. Further, in-depth investigation on plant-nanoparticles interactions creates new avenues toward crop improvement via enhanced crop yield, disease resistance, and efficient nutrient utilization. The incorporation of nanomaterial with smart agrochemical activities and establishing a new framework relevant to enhance efficacy ultimately help to address the social acceptance, potential hazards, and management issues in the future. Here, we highlight the role of nanomaterial or nanocomposite as a sustainable as well stable alternative in crop protection and production. Additionally, the information on the controlled released system, role in interaction with soil and microbiome, the promising role of nanocomposite as nanopesticide, nanoherbicide, nanofertilizer, and their limitations in agrochemical activities are discussed in the present review.

Morphological features and mechanical properties of nanofibers scaffolds of polylactic acid modified with hydroxyapatite/CdSe for wound healing applications

Ternary nanocomposites, including graphene oxide (GO), hydroxyapatite (HAP), and cadmium selenite (CdSe) have been encapsulated into nanofibrous scaffolds of polylactic acid. These compositions were indexed as HAP@PLA (C1), CdSe@PLA (C2), HAP/CdSe@PLA (C3), HAP/GO@PLA (C4), and HAP/CdSe/GO@PLA (C5). Structural confirmation is executed by XRD and XPS techniques, while FESEM performs morphological characteristics. CdSe and GO dopants cause a significant increase in nanofiber diameter, HAP/GO@PLA (C4), showing thin surface fibers with fiber diameter up to 3.1 μm, followed by HAP/CdSe/GO@PLA (C4) composite that belongs to filament size up to 2.1 μm. On the other hand, the mechanical properties reveal that the dual dopant composites HAP/CdSe@PLA (C3) and HAP/GO@PLA (C4) hit the maximum tensile fracture values with 1.49 ± 0.3 and 0.99 ± 0.2 MPa. Further, the ternary C5 composite represents the lowest contact angle of 86.1 ± 3.7°. The antibacterial activity increased from 32.4 ± 9.7 and 28.4 ± 6.5% to be 85.3 ± 4.6 and 88.1 ± 5.6% for C1 and C5, respectively, against both E. coli and S. aureus in dark conditions. Moreover, the antibacterial potency enhanced from 75.4 ± 7.6 to be 83.5 ± 6.5 from dark to light conditions against E. coli for the composition of PLA containing the binary composition of HAP/CdSe.

A green electrolysis of silver-decorated MoS2 nanocomposite with an enhanced antibacterial effect and low cytotoxicity

To tackle the devastating microbial infections for the public health, a continuous search for effective and safe nanobiocides based on their prominent nanoscale effects has been extensively explored during past decades. In this study, a green electrolysis method was employed to synthesize silver-doped molybdenum sulfide (Ag@MoS₂) composite materials. The obtained nanocomposites exhibited a sheet-like structure with a large specific surface area, which contributed to the efficient loading and refined distribution of silver nanoparticles. G^- E. coli and G ⁺ S. aureus were used as model bacteria for the antibacterial test, which revealed enhanced antibacterial activity of produced nanocomposites with an identified destructive effect on preformed biofilms. It was found that within 72 hour incubation, 20 μg mL^-1 Ag@MoS₂ was sufficient to inhibit the growth of E. coli and S. aureus without visible colony formation, pointing to a desirable long-term antibacterial activity. Further a mechanistic antibiosis study of Ag@MoS₂ indicated the involvement of a generation of reactive oxygen species. Notably, owing to the well-distributed silver nanoparticles on the nontoxic MoS₂ nanosheet, the cytotoxicity evaluation results revealed that produced nanocomposites exhibited negligible toxicity to mammalian cells, and thereby held promising potential for biomedical applications.

The recent progress in photothermal-triggered bacterial eradication

Increasing evidence suggested that bacterial infection diseases posed a great threat to human health and became the leading cause of mortality. However, the abuse of antibiotics and their residues in the environment result in the emergence and prevalence of drug-resistant bacteria. Photothermal therapy (PTT) has received considerable attention owing to its noninvasiveness, and proved to be promising in preventing bacterial infection diseases. In this review, we first surveyed the recent progress of PTT-based responsive targeting strategies for bacterial killing. We then highlighted the PTT-based smart designs of bio-films, hydrogels and synergistic methods for treating bacterial infections. Existing challenges and perspectives are also discussed to inspire the future development of a PTT-based platform for the efficient therapy of bacterial infections.

Dual stimuli-responsive metal-organic framework-based nanosystem for synergistic photothermal/pharmacological antibacterial therapy

The serious threat of drug-resistant bacterial pathogens has arisen through overuse of antibiotics. Photothermal therapy (PTT) has come to prominence as viable alternative strategy for antibacterial therapy. In this work, we report a NIR/pH dual stimuli-responsive antibacterial formulation based on zeolitic imidazolate frameworks-8 (ZIF-8) with strong antibacterial activity that combines photothermal heating with enhanced antibiotic delivery. ZIF-8 with polydopamine (PDA) surface modification was used to encapsulate the antibiotic vancomycin to construct a dual stimuli-responsive antimicrobial formulation (Van@ZIF-8@PDA). This treatment was tested against Gram-positive Mu50 (a vancomycin-intermediate S. aureus reference strain). Results showed that the PDA coating improved ZIF-8 stability and dispersion, while also conferring a high photothermal conversion efficiency. Hyperthermia activated by near-infrared (NIR) light irradiation, in conjunction with pH-dependent nanoparticle degradation to release vancomycin, enabled tight control of drug delivery that functioned synergistically in the elimination of both planktonic bacteria prior to biofilm formation and established biofilms. We found that this combined formulation compromises cell structure while also degrading bacterial DNA. Moreover, further investigation showed that the Van@ZIF-8@PDA nanoparticles exhibit good biocompatibility, with low toxicity toward host organs and tissues, while also reducing the antibiotic concentration needed for effective bacterial control. Finally, we treated Mu50 in a mouse model of skin abscess and found that Van@ZIF-8@PDA was effective and safe in vivo. Cumulatively, this study shows that this NIR/pH dual stimuli-responsive nanoparticle-based formulation offers a promising potential strategy for clinical application against bacterial infection that circumvents antibiotic resistance.

Graphene-Based Antimicrobial Biomedical Surfaces

Biomedical application of graphene derivatives have been intensively studied in last decade. With the exceptional structural, thermal, electrical, and mechanical properties, these materials have attracted immense attention of biomedical scientists to utilize graphene derivatives in biomedical devices to improve their performance or to achieve desired functions. Surfaces of graphene derivatives including graphite, graphene, graphene oxide and reduce graphene oxide have been demonstrated to pave an excellent platform for antimicrobial behavior, enhanced biocompatibility, tissue engineering, biosensors and drug delivery. This review focuses on the recent advancement in the research of biomedical devices with the coatings or highly structured polymer nanocomposite surfaces of graphene derivatives for antimicrobial activity and sterile surfaces comprising an entirely new class of antibacterial materials. Overall, we aim to highlight on the potential of these materials, current understanding and knowledge gap in the antimicrobial behavior and biocompatibility to be utilized of their coatings to prevent the cross infections.

Nanofibers of cellulose acetate containing ZnO nanoparticles/graphene oxide for wound healing applications

A combination of nanostructured zinc oxide (ZnO) or graphene oxide or both of them with cellulose acetate (CA) enhances a new functionality of nanofibers aiming to improve bio-composite materials for wound healing application. The obtained nanofibers have been investigated using XRD, FTIR, and FESEM. It was observed that the maximum height of the roughness increased from 253 to 651.9 nm for both GO and ZnO/GO in the powdered phase, while it plunged from 613 to 482 nm and developed to 801 nm for ZnO@CA, GO@CA, and ZnO/GO@CA, receptively. Further, the mechanical properties of the obtained scaffolds have been tested and displayed a tremendous variation of tensile strength from 5.44 ± 0.81 to 12.87 ± 0.93 and 8.82 ± 1.2 MPa, while the toughness increased from 23.29 ± 1.4 to 68.95 ± 4.5 and 57.75 ± 3.6 MJ/m³ for ZnO@CA, GO@CA and ZnO/GO@CA, receptively. Moreover, the cell viability was investigated and showed a progression of 97.38 ± 3.9% for ZnO/GO@CA. Furthermore, the adhesion of human fibroblasts cell line towards the obtained nanofibrous scaffolds were examined and displayed that cells were proliferated and spread considerably through the scaffolds, whereas their filopodia have followed the morphology of the fibers.

Antibacterial and antibiofilm properties of graphene and its derivatives

Infections resulting from bacteria and biofilms have become a huge problem threatening human health. In recent years, the antibacterial and antibiofilm effects of graphene and its derivatives have been extensively studied. However, there continues to be some controversy over whether graphene and its derivatives can resist infection and biofilms. Moreover, the antibacterial mechanism and cytotoxicity of graphene and its derivatives are unclear. In the present review, antibacterial and antibiofilm abilities of graphene and its derivatives in solution, on the surface are reviewed, and their toxicity and possible mechanisms are also reviewed. Furthermore, we propose possible future development directions for graphene and its derivatives in antibacterial and antibiofilm applications.

Phase-transfer-assisted synthesis of cysteine-Ag nanoparticles/graphene oxide nanocomposite and its enhanced performance in antibiosis and biosensing

We report a facile, rapid, phase-transfer-assisted process to prepare Ag nanoparticles (AgNP) loaded graphene oxide (GO) nanocomposite, by using cysteine as a highly-effective phase transfer agent for AgNP movement from organic phase to water and subsequently as a covalent linkage for immobilizing AgNP on GO. The obtained c-Ag/GO nanocomposite possesses high nanoparticle loading efficiency, small particle size and monodispersity, strong binding force and good water dispersibility, which endow it with great potential in a variety of bio-applications. To illustrate potentail application, c-Ag/GO and its derivatives c-Ag/rGO were used for antibiosis and biosensing, respectively. The c-Ag/GO composite demonstrates high antibacterial activity against E. coli with a minimal bactericidal concentration of 10 μg ml^-1. The biosensor based on c-Ag/rGO exhibits rapid and sensitive response for uric acid detection with a detection limit of 0.025 μM, a sensitivity of 5.76 μA mM^-1 and a wide linear range of 0.025 ∼ 2250 μM. The comparative analysis with relevant nanocomposites also reveals the precedence of c-Ag/GO in these applications, thus highlighting the advantages of the developed preparation method for c-Ag/GO.

Preparation, characterization and anti-cancer activity of graphene oxide-‑silver nanocomposite

This work reported the preparation, characterization, cytotoxicity of green synthesized Lespedeza cuneate mediated silver nanoparticles (Lc-AgNPs) and graphene oxide‑silver nanocomposite (GO-AgNComp) using Lc-AgNPs. The UV absorption spectrum at 419 nm indicated the successful formation of GO-AgNComp. The TEM analysis displayed the thin sheet of graphene decorated Lc-AgNPs in GO-AgNComp. Zeta potential was -13.2 mV for Lc-AgNPs and -30.5 mV for GO-AgNComp. The photothermal conversion efficiency was calculated as 31.09% for GO-AgNComp. The negatively charged zeta potential of GO-AgNComp enhanced its cellular penetration through enhanced permeability and retention (EPR) effect. The near-infrared laser (NIR) induced the anticancer activity of Lc-AgNPs and GO-AgNComp in human lung cancer cells (A549) and brain tumour (LN229). The results indicated that about 50% of A549 cells and LN229 cells were ablated by treatment of 24.73 ± 2.98 μg/mL and 27.34 ± 1.62 μg/mL of Lc-AgNPs, as well by 15.46 ± 2.31 μg/mL and 20.95 ± 1.35 μg/mL of GO-AgNComp respectively. Moreover, GO-AgNComp was not cytotoxic to normal mouse fibroblast cells (NIH3T3), but it caused the cancer cell death in A549 and LN229 through ROS generation, nuclear damage, and mitochondrial membrane potential (∆ψm) loss. This work reported the anticancer potential of GO-AgNComp, which deserves further study on the molecular elucidation of GO-AgNComp mediated human lung and tumour therapy.

Nanomaterials for the Photothermal Killing of Bacteria

An upsurge in the multidrug-resistant (MDR) bacterial pestilence is a global cause for concern in terms of human health. Lately, nanomaterials with photothermal effects have assisted in the efficient killing of MDR bacteria, attributable to their uncommon plasmonic, photocatalytic, and structural properties. Examinations of substantial amounts of photothermally enabled nanomaterials have shown bactericidal effects in an optimized time under near-infrared (NIR) light irradiation. In this review, we have compiled recent advances in photothermally enabled nanomaterials for antibacterial activities and their mechanisms. Photothermally enabled nanomaterials are classified into three groups, including metal-, carbon-, and polymer-based nanomaterials. Based on substantial accomplishments with photothermally enabled nanomaterials, we have inferred current trends and their prospective clinical applications.