Graphene-based nanomaterials for drug and/or gene delivery, bioimaging, and tissue engineering

Recent breakthroughs in graphene quantum dot-enhanced sonodynamic and photodynamic therapy

Water-soluble graphene quantum dots (GQDs) have recently exhibited considerable potential for diverse biomedical applications owing to their exceptional optical and chemical properties. However, the pronounced heterogeneity in the composition, size, and morphology of GQDs poses challenges for a comprehensive understanding of the intricate correlation between their structural attributes and functional properties. This variability also introduces complexities in scaling the production processes and addressing safety considerations. Light and sound have firmly established their role in clinical applications as pivotal energy sources for minimally invasive therapeutic interventions. Given the limited penetration depth of light, photodynamic therapy (PDT) predominantly targets superficial conditions such as dermatological disorders, head and neck malignancies, ocular ailments, and early-stage esophageal cancer. Conversely, ultrasound-based sonodynamic therapy (SDT) capitalizes on its superior ability to propagate and focus ultrasound within biological tissues, enabling a diverse range of therapeutic applications, including the management of gliomas, breast cancer, hematological tumors, and modulation of the blood-brain barrier (BBB). Considering the advancements in theranostic and precision therapies, reevaluating these conventional energy sources and their associated sensitizers is imperative. This review introduces three prevalent treatment modalities that harness light and sound stimuli: PDT, SDT, and a synergistic approach that integrates PDT and SDT. This study delineated the therapeutic dynamics and contemporary designs of sensitizers tailored to these modalities. By exploring the historical context of the field and elucidating the latest design strategies, this review underscores the pivotal role of GQDs in propelling the evolution of PDT and SDT. This aspires to stimulate researchers to develop "multimodal" therapies integrating both light and sound stimuli.

Biomedical applications of graphene-based nanomaterials: recent progress, challenges, and prospects in highly sensitive biosensors

Graphene-based nanomaterials (graphene, graphene oxide, reduced graphene oxide, graphene quantum dots, graphene-based nanocomposites, etc.) are emerging as an extremely important class of nanomaterials primarily because of their unique and advantageous physical, chemical, biological, and optoelectronic aspects. These features have resulted in uses across diverse areas of scientific research. Among all other applications, they are found to be particularly useful in designing highly sensitive biosensors. Numerous studies have established their efficacy in sensing pathogens and other biomolecules allowing for the rapid diagnosis of various diseases. Considering the growing importance and popularity of graphene-based materials for biosensing applications, this review aims to provide the readers with a summary of the recent progress in the concerned domain and highlights the challenges associated with the synthesis and application of these multifunctional materials.

Nanoplatform based on carbon nanoparticles loaded with doxorubicin enhances apoptosis by generating reactive oxygen species for effective cancer therapy

At present, due to its wide application and relatively low cost, chemotherapy remains a clinically important cancer treatment option; however, a number of chemotherapeutic drugs have important limitations, such as lack of specificity, high toxicity and side effects, and multi-drug resistance. The emergence of nanocarriers has removed numerous clinical application limitations of certain antitumor chemotherapy drugs and has been widely used in the treatment of tumors with nanodrugs. The present study used carbon nanoparticles (CNPs) as a nanocarrier for doxorubicin (DOX) to form the novel nanomedicine delivery system (CNPs@DOX)was demonstrated by UV-vis and fluorescence spectrophotometry, ζ potential and TEM characterization experiments. The results confirmed the successful preparation of CNPs@DOX nanoparticles with a particle size of 96±17 nm, a wide range of absorption and a negatively charged surface. Furthermore, CNPs@DOX produced more reactive oxygen species and induced apoptosis, and thus exhibited higher cytotoxicity than DOX, which is a small molecule anticancer drug without a nanocarrier delivery system.. The present study provides a strategy for the treatment of tumors with nanomedicine.

Graphene (GNP) reinforced 3D printing nanocomposites: An advanced structural perspective

The influence of macro-micro structural design on the mechanical response of structural nanocomposites is substantial. The advancement of additive manufacturing especially three-dimensional (3-D) printing technology offers a promising avenue for the efficient and precise fabrication of multi-functional low-weight and high-strength nanocomposites. In contemporary discourse, there is a notable emphasis on carbon-based nanomaterials as nanofillers for structural composites due to their substantial specific surface area and exceptional load-bearing ability in mechanical structures. Notably, graphene, a distinctive two-dimensional (2-D) nanomaterial, exhibits very large elastic modulus and ultimate strength as well as remarkable plasticity. The utilization of graphene nanoparticles (GNPs) in the field of 3-D printing enables the production of intricate three-dimensional structures of varying sizes and configurations. This is achieved through the macro-assembly process, which facilitates the creation of a well-organized distribution of graphene and the establishment of a comprehensive physical network through precise micro-regulation. This paper presents an overview of multiscale structural composites that are strengthened by the incorporation of graphene and prepared by 3-D printing. The composites discussed in this study encompass graphene-polymer composites, graphene-ceramic composites, and graphene-metal composites. Furthermore, an analysis of the present obstacles and potential future advancements in this rapidly expanding domain is anticipated.

Influence of titanium nanoscale surface roughness on fibrinogen and albumin protein adsorption kinetics and platelet responses

Biomaterials with nanoscale topography have been increasingly investigated for medical device applications to improve tissue-material interactions. This study assessed the impact of nanoengineered titanium surface domain sizes on early biological responses that can significantly affect tissue interactions. Nanostructured titanium coatings with distinct nanoscale surface roughness were deposited on quartz crystal microbalance with dissipation (QCM-D) sensors by physical vapor deposition. Physico-chemical characterization was conducted to assess nanoscale surface roughness, nano-topographical morphology, wettability, and atomic composition. The results demonstrated increased projected surface area and hydrophilicity with increasing nanoscale surface roughness. The adsorption properties of albumin and fibrinogen, two major plasma proteins that readily encounter implanted surfaces, on the nanostructured surfaces were measured using QCM-D. Significant differences in the amounts and viscoelastic properties of adsorbed proteins were observed, dependent on the surface roughness, protein type, protein concentration, and protein binding affinity. The impact of protein adsorption on subsequent biological responses was also examined using qualitative and quantitative in vitro evaluation of human platelet adhesion, aggregation, and activation. Qualitative platelet morphology assessment indicated increased platelet activation/aggregation on titanium surfaces with increased roughness. These data suggest that nanoscale differences in titanium surface roughness influence biological responses that may affect implant integration.

Unveiling the contemporary progress of graphene-based nanomaterials with a particular focus on the removal of contaminants from water: a comprehensive review

Water scarcity and pollution pose significant challenges to global environmental sustainability and public health. As these concerns intensify, the quest for innovative and efficient water treatment technologies becomes paramount. In recent years, graphene-based nanomaterials have emerged as frontrunners in this pursuit, showcasing exceptional properties that hold immense promise for addressing water contamination issues. Graphene, a single layer of carbon atoms arranged in a hexagonal lattice, exhibits extraordinary mechanical, electrical, and chemical properties. These inherent characteristics have led to a surge of interest in leveraging graphene derivatives, such as graphene oxide (GO), reduced graphene oxide and functionalized graphene, for water treatment applications. The ability of graphene-based nanomaterials to adsorb, catalyze, and photocatalyze contaminants makes them highly versatile in addressing diverse pollutants present in water sources. This review will delve into the synthesis methods employed for graphene-based nanomaterials and explore the structural modifications and functionalization strategies implemented to increase their pollutant removal performance in water treatment. By offering a critical analysis of existing literature and highlighting recent innovations, it will guide future research toward the rational design and optimization of graphene-based nanomaterials for water decontamination. The exploration of interdisciplinary approaches and cutting-edge technologies underscores the evolving landscape of graphene-based water treatment, fostering a path toward sustainable and scalable solutions. Overall, the authors believe that this review will serve as a valuable resource for researchers, engineers, and policymakers working toward sustainable and effective solutions for water purification.

Advances in nanobased platforms for cardiovascular diseases: Early diagnosis, imaging, treatment, and tissue engineering

Cardiovascular diseases (CVDs) present a significant threat to health, with traditional therapeutics based treatment being hindered by inefficiencies, limited biological effects, and resistance to conventional drug. Addressing these challenges requires advanced approaches for early disease diagnosis and therapy. Nanotechnology and nanomedicine have emerged as promising avenues for personalized CVD diagnosis and treatment through theranostic agents. Nanoparticles serve as nanodevices or nanocarriers, efficiently transporting drugs to injury sites. These nanocarriers offer the potential for precise drug and gene delivery, overcoming issues like bioavailability and solubility. By attaching specific target molecules to nanoparticle surfaces, controlled drug release to targeted areas becomes feasible. In the field of cardiology, nanoplatforms have gained popularity due to their attributes, such as passive or active targeting of cardiac tissues, enhanced sensitivity and specificity, and easy penetration into heart and artery tissues due to their small size. However, concerns persist about the immunogenicity and cytotoxicity of nanomaterials, necessitating careful consideration. Nanoparticles also hold promise for CVD diagnosis and imaging, enabling straightforward diagnostic procedures and real-time tracking during therapy. Nanotechnology has revolutionized cardiovascular imaging, yielding multimodal and multifunctional vehicles that outperform traditional methods. The paper provides an overview of nanomaterial delivery routes, targeting techniques, and recent advances in treating, diagnosing, and engineering tissues for CVDs. It also discusses the future potential of nanomaterials in CVDs, including theranostics, aiming to enhance cardiovascular treatment in clinical practice. Ultimately, refining nanocarriers and delivery methods has the potential to enhance treatment effectiveness, minimize side effects, and improve patients' well-being and outcomes.

Nanomaterials Solutions for Contraception: Concerns, Advances, and Prospects

Preventing unintentional pregnancy is one of the goals of a global public health policy to minimize effects on individuals, families, and society. Various contraceptive formulations with high effectiveness and acceptance, including intrauterine devices, hormonal patches for females, and condoms and vasectomy for males, have been developed and adopted over the last decades. However, distinct breakthroughs of contraceptive techniques have not yet been achieved, while the associated long-term adverse effects are insurmountable, such as endocrine system disorder along with hormone administration, invasive ligation, and slowly restored fertility after removal of intrauterine devices. Spurred by developments of nanomaterials and bionanotechnologies, advanced contraceptives could be fulfilled via nanomaterial solutions with much safer and more controllable and effective approaches to meet various and specific needs for women and men at different reproductive stages. Nanomedicine techniques have been extended to develop contraceptive methods, such as the targeted drug delivery and controlled release of hormone using nanocarriers for females and physical stimulation assisted vasectomy using functional nanomaterials via photothermal treatment or magnetic hyperthermia for males. Nanomaterial solutions for advanced contraceptives offer significantly improved biosafety, noninvasive administration, and controllable reversibility. This review summarizes the nanomaterial solutions to female and male contraceptives including the working mechanisms, clinical concerns, and their merits and demerits. This work also reviewed the nanomaterials that have been adopted in contraceptive applications. In addition, we further discuss safety considerations and future perspectives of nanomaterials in nanostrategy development for next-generation contraceptives. We expect that nanomaterials would potentially replace conventional materials for contraception in the near future.

Recent advances in tailoring stimuli-responsive hybrid scaffolds for cardiac tissue engineering and allied applications

To recapitulate bio-physical properties and functional behaviour of native heart tissues, recent tissue engineering-based approaches are focused on developing smart/stimuli-responsive materials for interfacing cardiac cells. Overcoming the drawbacks of the traditionally used biomaterials, these smart materials portray outstanding mechanical and conductive properties while promoting cell-cell interaction and cell-matrix transduction cues in such excitable tissues. To date, a large number of stimuli-responsive materials have been employed for interfacing cardiac tissues alone or in combination with natural/synthetic materials for cardiac tissue engineering. However, their comprehensive classification and a comparative analysis of the role played by these materials in regulating cardiac cell behaviour and in vivo metabolism are much less discussed. In an attempt to cover the recent advances in fabricating stimuli-responsive biomaterials for engineering cardiac tissues, this review details the role of these materials in modulating cardiomyocyte behaviour, functionality and surrounding matrix properties. Furthermore, concerns and challenges regarding the clinical translation of these materials and the possibility of using such materials for the fabrication of bio-actuators and bioelectronic devices are discussed.

Nanopore Electroporation Device for DNA Transfection into Various Spreading and Nonadherent Cell Types

Cell transfection plays a crucial role in the study of gene function and regulation of gene expression. The existing gene transfection methods, such as chemical carriers, viruses, electroporation, and microinjection, suffer from limitations, including cell type dependence, reliance on cellular endocytosis, low efficiency, safety concerns, and technical complexity. Nanopore-coupled electroporation offers a promising approach to localizing electric fields for efficient cell membrane perforation and nucleic acid transfection. However, the applicability of nanopore electroporation technology across different cell types lacks a systematic investigation. In this study, we explore the potential of nanopore electroporation for transfecting DNA plasmids into various cell types. Our nanopore electroporation device employs track-etched membranes as the core component. We find that nanopore electroporation efficiently transfects adherent cells, including well-spreading epithelial-like HeLa cells, cardiomyocyte-like HL-1 cells, and dendritic-cell-like DC2.4 cells. However, it shows a limited transfection efficiency in weakly spreading macrophages (RAW264.7) and suspension cells (Jurkat). To gain insights into these observations, we develop a COMSOL model, revealing that nanopore electroporation better localizes the electric field on adherent and well-spreading cells, promoting favorable membrane poration conditions. Our findings provide valuable references for advancing nanopore electroporation as a high-throughput, safe, and efficient gene transfection platform.

Engineering nanoparticle toolkits for mRNA delivery

The concept of using mRNA to produce its own medicine in situ in the body makes it an ideal drug candidate, holding great potential to revolutionize the way we approach medicine. The unique characteristics of mRNA, as well as its customizable biomedical functions, call for the rational design of delivery systems to protect and transport mRNA molecules. In this review, a nanoparticle toolkit is presented for the development of mRNA-based therapeutics from a drug delivery perspective. Nano-delivery systems derived from either natural systems or chemical synthesis, in the nature of organic or inorganic materials, are summarised. Delivery strategies in controlling the tissue targeting and mRNA release, as well as the role of nanoparticles in building and boosting the activity of mRNA drugs, have also been introduced. In the end, our insights into the clinical and translational development of mRNA nano-drugs are presented.

Investigating of the anticancer activity of salen/salophen metal complexes based on graphene quantum dots: Induction of apoptosis as part of biological activity

This research work is the first report on the synthesis and stabilization of [Fe-Salophen] and [Fe-Salen] complexes by two methods of surface modification and anchoring of synthesized Schiff base ligand on the surface of graphene quantum dots (GQDs). The GQDs contain oxygenated functional groups that can act as non-radiative electron-hole recombination centers. Therefore removing these oxygen functional groups may improve quantum yield by reducing or deactivating the surface. In this work, GQDs with the amine functional group were synthesized with a quantum yield of 37.48%. The physicochemical properties of GQDs were investigated by Ultraviolet-visible (UV-Vis) and fluorescence spectroscopies, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), Powder X-ray diffraction (PXRD), Transmission electron microscope (TEM). The synthesis of GQDs-[Fe-Salen] and GQDs-[Fe-Salophen] was evaluated by FT-IR, Inductively coupled plasma atomic emission spectroscopy (ICP-AES) and Energy dispersive X-Ray analysis (EDX) analyses. Then, using MTT- assay, annexin V-FITC/PI, DAPI staining and cellular uptake assays, the biochemical activity of these complexes on the MCF7 cell line was investigated. The results shows that GQDs-[Fe-Salen] and GQDs-[Fe-Salophen] affect the survival of MCF7 cancer cells and, by nuclear fragmentation cause 35.77% and 19.41% of early apoptosis in cells, respectively. Also was found cellular uptake of GQDs-[Fe-Salen] is higher than that of GQDs-[Fe-Salophen].

Assembling phenyl-modified colloidal silica on graphene oxide towards ethanol redispersible graphene oxide powder

Recently, ethanol has shown promising potential in the large-scale reduction of graphene oxide (GO) into graphene. However, dispersion of GO powder in ethanol is a challenge due to its poor affinity, which hinders permeation and intercalation of ethanol between GO molecule layers. In this paper, phenyl-modified colloidal silica nanospheres (PSNS) were synthesized by phenyl-tri-ethoxy-silane (PTES) and tetra-ethyl ortho-silicate (TEOS) using a sol-gel method. PSNS was then assembled onto a GO surface to form a PSNS@GO structure by possible non-covalent π-π stacking interactions between the phenyl groups and GO molecules. The surface morphology, chemical composition, and dispersion stability were analyzed by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetry, Raman spectroscopy, X-ray diffractometry, nuclear magnetic resonance, and particle sedimentation test. The results showed that the as-assembled PSNS@GO suspension had excellent dispersion stability with an optimal PSNS concentration of 5 vol% PTES. With the optimized PSNS@GO, ethanol can permeate between the GO layers and intercalate along with PSNS particles via formation of hydrogen bonds between assembled PSNS on GO and ethanol, achieving a stable dispersion of GO in ethanol. The optimized PSNS@GO powder remained redispersible after drying and milling according to this interaction mechanism which is favorable for large scale reduction processes. Higher PTES concentration may result in agglomeration of PSNS and formation of wrapping structures of PSNS@GO after drying and worsen its dispersion capability.

Surface Area of Graphene Governs Its Neurotoxicity

Due to their unique physicochemical properties, graphene and its derivatives are widely exploited for biomedical applications. It has been shown that graphene may exert different degrees of toxicity in in vivo or in vitro models when administered via different routes and penetrated through physiological barriers, subsequently being distributed within tissues or located within cells. In this study, in vitro neurotoxicity of graphene with different surface areas (150 and 750 m²/g) was examined on dopaminergic neuron model cells. SH-SY5Y cells were treated with graphene possessing two different surface areas (150 and 750 m²/g) in different concentrations between 400 and 3.125 μg/mL, and the cytotoxic and genotoxic effects were investigated. Both sizes of graphene have shown increased cell viability in decreasing concentrations. Cell damage increased with higher surface area. Lactate dehydrogenase (LDH) results have concluded that the viability loss of the cells is not through membrane damage. Neither of the two graphene types showed damage through lipid peroxidation (MDA) oxidative stress pathway. Glutathione (GSH) values increased within the first 24 and 48 h for both types of graphene. This increase suggests that graphene has an antioxidant effect on the SH-SY5Y model neurons. Comet analysis shows that graphene does not show genotoxicity on either surface area. Although there are many studies on graphene and its derivatives on their use with different cells in the literature, there are conflicting results in these studies, and most of the literature is focused on graphene oxide. Among these studies, no study examining the effect of graphene surface areas on the cell was found. Our study contributes to the literature in terms of examining the cytotoxic and genotoxic behavior of graphene with different surface areas.

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-Related Nanomaterials for Biomedical Applications

This paper builds on the context and recent progress on the control, reproducibility, and limitations of using graphene and graphene-related materials (GRMs) in biomedical applications. The review describes the human hazard assessment of GRMs in in vitro and in vivo studies, highlights the composition-structure-activity relationships that cause toxicity for these substances, and identifies the key parameters that determine the activation of their biological effects. GRMs are designed to offer the advantage of facilitating unique biomedical applications that impact different techniques in medicine, especially in neuroscience. Due to the increasing utilization of GRMs, there is a need to comprehensively assess the potential impact of these materials on human health. Various outcomes associated with GRMs, including biocompatibility, biodegradability, beneficial effects on cell proliferation, differentiation rates, apoptosis, necrosis, autophagy, oxidative stress, physical destruction, DNA damage, and inflammatory responses, have led to an increasing interest in these regenerative nanostructured materials. Considering the existence of graphene-related nanomaterials with different physicochemical properties, the materials are expected to exhibit unique modes of interactions with biomolecules, cells, and tissues depending on their size, chemical composition, and hydrophil-to-hydrophobe ratio. Understanding such interactions is crucial from two perspectives, namely, from the perspectives of their toxicity and biological uses. The main aim of this study is to assess and tune the diverse properties that must be considered when planning biomedical applications. These properties include flexibility, transparency, surface chemistry (hydrophil-hydrophobe ratio), thermoelectrical conductibility, loading and release capacity, and biocompatibility.

Graphene and its derivatives: "one stone, three birds" strategy for orthopedic implant-associated infections

Orthopedic implants provide an avascular surface for microbial attachment and biofilm formation, impeding the entry of immune cells and the diffusion of antibiotics. The above is an important cause of dental and orthopedic implant-associated infection (IAI). For the prevention and treatment of IAI, the drawbacks of antibiotic resistance and surgical treatment are increasingly apparent. Due to their outstanding biological properties such as biocompatibility, immunomodulatory effects, and antibacterial properties, graphene-based nanomaterials (GBNs) have been applied to bone tissue engineering to deal with IAI, and in particular have great potential application in drug/gene carriers, multi-functional platforms, and coating forms. Here we review the latest research progress and achievements in GBNs for the prevention and treatment of IAI, mainly including their biomedical applications for antibacterial and immunomodulation effects, and for inducing osteogenesis. Furthermore, the biosafety of graphene family materials in bone tissue regeneration and the feasibility of clinical application are critically analyzed and discussed.

Progress and challenges of graphene and its congeners for biomedical applications

Nanomaterials by virtue of their small size and enhanced surface area, present unique physicochemical properties that enjoy widespread applications in bioengineering, biomedicine, biotechnology, disease diagnosis, and therapy. In recent years, graphene and its derivatives have attracted a great deal of attention in various applications, including photovoltaics, electronics, energy storage, catalysis, sensing, and biotechnology owing to their exceptional structural, optical, thermal, mechanical, and electrical. Graphene is a two-dimensional sheet of sp2 hybridized carbon atoms of atomic thickness, which are arranged in a honeycomb crystal lattice structure. Graphene derivatives are graphene oxide (GO) and reduced graphene oxide (rGO), which are highly oxidized and less oxidized forms of graphene, respectively. Another form of graphene is graphene quantum dots (GQDs), having a size of less than 20 nm. Contemporary graphene research focuses on using graphene nanomaterials for biomedical purposes as they have a large surface area for loading biomolecules and medicine and offer the potential for the conjugation of fluorescent dyes or quantum dots for bioimaging. The present review begins with the synthesis, purification, structure, and properties of graphene nanomaterials. Then, we focussed on the biomedical application of graphene nanomaterials with special emphasis on drug delivery, bioimaging, biosensing, tissue engineering, gene delivery, and chemotherapy. The implications of graphene nanomaterials on human health and the environment have also been summarized due to their exposure to their biomedical applications. This review is anticipated to offer useful existing understanding and inspire new concepts to advance secure and effective graphene nanomaterials-based biomedical devices.

Antimicrobial Activity of Graphene-Based Nanocomposites: Synthesis, Characterization, and Their Applications for Human Welfare

Graphene (GN)-related nanomaterials such as graphene oxide, reduced graphene oxide, quantum dots, etc., and their composites have attracted significant interest owing to their efficient antimicrobial properties and thus newer GN-based composites are being readily developed, characterized, and explored for clinical applications by scientists worldwide. The GN offers excellent surface properties, i.e., a large surface area, pH sensitivity, and significant biocompatibility with the biological system. In recent years, GN has found applications in tissue engineering owing to its impressive stiffness, mechanical strength, electrical conductivity, and the ability to innovate in two-dimensional (2D) and three-dimensional (3D) design. It also offers a photothermic effect that potentiates the targeted killing of cells via physicochemical interactions. It is generally synthesized by physical and chemical methods and is characterized by modern and sophisticated analytical techniques such as NMR, Raman spectroscopy, electron microscopy, etc. A lot of reports show the successful conjugation of GN with existing repurposed drugs, which improves their therapeutic efficacy against many microbial infections and also its potential application in drug delivery. Thus, in this review, the antimicrobial potentialities of GN-based nanomaterials, their synthesis, and their toxicities in biological systems are discussed.

Preparation and sustained-release properties of poly(lactic acid)/graphene oxide porous biomimetic composite scaffolds loaded with salvianolic acid B

Biomimetic scaffolds loaded with drugs can improve the osteogenesis and neovascularisation of scaffolds. A series of PLA/GO/Sal-B drug-loaded scaffolds was prepared by thermally induced phase separation. The addition of Sal-B increased the diameter of the fibres, but the scaffold showed a porous nanofibrous structure after drug release. X-ray diffraction results showed that the addition of Sal-B did not affect the formation of the nanofibre biomimetic structure of the scaffold. FTIR results indicated a certain interaction between Sal-B and PLA/GO. Water absorption and porosity test results revealed that the scaffolds had good hydrophilicity and appropriate porosity. The addition of Sal-B was also conducive to the formation of sediments possibly due to the good water solubility of Sal-B itself. The prepared scaffolds had good blood compatibility and cytocompatibility, and a small additional amount of Sal-B could significantly promote cell proliferation and alkaline phosphatase activity. Their sustained release performance indicated that the biomimetic scaffolds had controlled the release of Sal-B. The kinetic model showed that the PLA/GO/Sal-B drug-loaded biomimetic scaffolds followed the diffusion mechanism.

State-of-the-art developments in carbon quantum dots (CQDs): Photo-catalysis, bio-imaging, and bio-sensing applications

Carbon quantum dots (CQDs), the intensifying nanostructured form of carbon material, have exhibited incredible impetus in several research fields such as bio-imaging, bio-sensing, drug delivery systems, optoelectronics, photovoltaics, and photocatalysis, thanks to their exceptional properties. The CQDs show extensive photonic and electronic properties, as well as their light-collecting, tunable photoluminescence, remarkable up-converted photoluminescence, and photo-induced transfer of electrons were widely studied. These properties have great advantages in a variety of visible-light-induced catalytic applications for the purpose of fully utilizing the energy from the solar spectrum. The major purpose of this review is to validate current improvements in the fabrication of CQDs, characteristics, and visible-light-induced catalytic applications, with a focus on CQDs multiple functions in photo-redox processes. We also examine the problems and future directions of CQD-based nanostructured materials in this growing research field, with an eye toward establishing a decisive role for CQDs in photocatalysis, bio-imaging, and bio-sensing applications that are enormously effective and stable over time. In the end, a look forward to future developments is presented, with a view to overcoming challenges and encouraging further research into this promising field.

Upconversion Nanostructures Applied in Theranostic Systems

Upconversion (UC) nanostructures, which can upconvert near-infrared (NIR) light with low energy to visible or UV light with higher energy, are investigated for theranostic applications. The surface of lanthanide (Ln)-doped UC nanostructures can be modified with different functional groups and bioconjugated with biomolecules for therapeutic systems. On the other hand, organic molecular-based UC nanostructures, by using the triplet-triplet annihilation (TTA) UC mechanism, have high UC quantum yields and do not require high excitation power. In this review, the major UC mechanisms in different nanostructures have been introduced, including the Ln-doped UC mechanism and the TTA UC mechanism. The design and fabrication of Ln-doped UC nanostructures and TTA UC-based UC nanostructures for theranostic applications have been reviewed and discussed. In addition, the current progress in the application of UC nanostructures for diagnosis and therapy has been summarized, including tumor-targeted bioimaging and chemotherapy, image-guided diagnosis and phototherapy, NIR-triggered controlled drug releasing and bioimaging. We also provide insight into the development of emerging UC nanostructures in the field of theranostics.

Carbon nanostructures: a comprehensive review of potential applications and toxic effects

There is no doubt that nanotechnology has revolutionized our life since the 1970s when it was first introduced. Nanomaterials have helped us to improve the current products and services we use. Among the different types of nanomaterials, the application of carbon-based nanomaterials in every aspect of our lives has rapidly grown over recent decades. This review discusses recent advances of those applications in distinct categories, including medical, industrial, and environmental applications. The first main section introduces nanomaterials, especially carbon-based nanomaterials. In the first section, we discussed medical applications, including medical biosensors, drug and gene delivery, cell and tissue labeling and imaging, tissue engineering, and the fight against bacterial and fungal infections. The next section discusses industrial applications, including agriculture, plastic, electronic, energy, and food industries. In addition, the environmental applications, including detection of air and water pollutions and removal of environmental pollutants, were vastly reviewed in the last section. In the conclusion section, we discussed challenges and future perspectives.

Enhanced aqueous dissolution of hydrophobic apixaban via direct incorporation of hydrophilic nanographene oxide

In this study, we have directly incorporated nanographene oxide (nGO) into a hydrophobic drug for enhanced dissolution performance through an antisolvent technique. Apixaban (APX) drug composites were synthesized with nGO incorporation ranging from 0.8% to 2.0% concentration. It was observed that the nGO was successfully embedded without any changes to the original drug crystal structure or physical properties. Dissolution of the drug composites was evaluated using US Pharmacopeia Paddle Method (USP 42). The time needed to reach a 50% release (T₅₀) reduced from 106 min to 24 min with the integration of 1.96% nGO in APX and the T₈₀ also dropped accordingly. Alternatively, dissolution rate showed promising performance with increase in nGO concentration. Initial dissolution rate increased dramatically from 74 µg/min to 540 µg/min. Further, work done in intestinal media revealed T₅₀ went from not dissolving to 79.0 min. Decreased lipophilicity or logP value and increased aqueous solubility are both accredited to hydrophilic nGO water dispersion, producing a hydrophilic channel into the drug crystal surfaces through intermolecular interaction. Additionally, physical, and chemical characterizations confirm that hydrophobic apixaban was successfully transformed into a hydrophilic composite, showing potential for this technology to improve dissolution rate of a model hydrophobic compound.

Cells and material-based strategies for regenerative endodontics

<p class = "Abstract" style = "margin: 0 cm; line-height: 32px; font-size: 12 pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); "><span lang = "EN-US">The carious process leads to inflammation of pulp tissue. Current care options include root canal treatment or apexification. These procedures, however, result in the loss of tooth vitality, sensitivity, and healing. Pulp capping and dental pulp regeneration are continually evolving techniques to regenerate pulp tissue, avoiding necrosis and loss of vitality. Many studies have successfully employed stem/progenitor cell populations, revascularization approaches, scaffolds or material-based strategies for pulp regeneration. Here we outline advantages and disadvantages of different methods and techniques which are currently being used in the field of regenerative endodontics. We also summarize recent findings on efficacious peptide-based materials which target the dental niche.<o:p></o:p></span></p>

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Pulp infection necessitates removal of necrotic, inflamed and infected tissue.

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Materials used clinically are inert (such as gutta percha, mineral trioxide aggregate).

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Recent developments in materials (angiogenic hydrogels, stem cell composites) have tuneable bioactivity.

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Dental pulp regeneration may now be possible through the use of bioactive systems, that guide regeneration.

Recent advances and challenges in graphene-based nanocomposite scaffolds for tissue engineering application

Graphene-based nanocomposites have recently attracted increasing attention in tissue engineering because of their extraordinary features. These biocompatible substances, in the presence of an apt microenvironment, can stimulate and sustain the growth and differentiation of stem cells into different lineages. This review discusses the characteristics of graphene and its derivatives, such as their excellent electrical signal transduction, carrier mobility, outstanding mechanical strength with improving surface characteristics, self-lubrication, antiwear properties, enormous specific surface area, and ease of functional group modification. Moreover, safety issues in the application of graphene and its derivatives in terms of biocompatibility, toxicity, and interaction with immune cells are discussed. We also describe the applicability of graphene-based nanocomposites in tissue healing and organ regeneration, particularly in the bone, cartilage, teeth, neurons, heart, skeletal muscle, and skin. The impacts of special textural and structural characteristics of graphene-based nanomaterials on the regeneration of various tissues are highlighted. Finally, the present review gives some hints on future research for the transformation of these exciting materials in clinical studies.

Fluorescent Biosensors for the Detection of Viruses Using Graphene and Two-Dimensional Carbon Nanomaterials

Two-dimensional carbon nanomaterials have been commonly employed in the field of biosensors to improve their sensitivity/limits of detection and shorten the analysis time. These nanomaterials act as efficient transducers because of their unique characteristics, such as high surface area and optical, electrical, and magnetic properties, which in turn have been exploited to create simple, quick, and low-cost biosensing platforms. In this review, graphene and two-dimensional carbon material-based fluorescent biosensors are covered between 2010 and 2021, for the detection of different human viruses. This review specifically focuses on the new developments in graphene and two-dimensional carbon nanomaterials for fluorescent biosensing based on the Förster resonance energy transfer (FRET) mechanism. The high-efficiency quenching capability of graphene via the FRET mechanism enhances the fluorescent-based biosensors. The review provides a comprehensive reference for the different types of carbon nanomaterials employed for the detection of viruses such as Rotavirus, Ebola virus, Influenza virus H3N2, HIV, Hepatitis C virus (HCV), and Hepatitis B virus (HBV). This review covers the various multiplexing detection technologies as a new direction in the development of biosensing platforms for virus detection. At the end of the review, the different challenges in the use of fluorescent biosensors, as well as some insights into how to overcome them, are highlighted.

Engineered 2D materials for optical bioimaging and path toward therapy and tissue engineering

Two-dimensional (2D) layered materials as a new class of nanomaterial are characterized by a list of exotic properties. These layered materials are investigated widely in several biomedical applications. A comprehensive understanding of the state-of-the-art developments of 2D materials designed for multiple nanoplatforms will aid researchers in various fields to broaden the scope of biomedical applications. Here, we review the advances in 2D material-based biomedical applications. First, we introduce the classification and properties of 2D materials. Next, we summarize surface and structural engineering methods of 2D materials where we discuss surface functionalization, defect, and strain engineering, and creating heterostructures based on layered materials for biomedical applications. After that, we discuss different biomedical applications. Then, we briefly introduced the emerging role of machine learning (ML) as a technological advancement to boost biomedical platforms. Finally, the current challenges, opportunities, and prospects on 2D materials in biomedical applications are discussed.

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Sub-Lethal Concentrations of Graphene Oxide Trigger Acute-Phase Response and Impairment of Phase-I Xenobiotic Metabolism in Upcyte® Hepatocytes

The impact of graphene oxide on hepatic functional cells represents a crucial evaluation step for its potential application in nanomedicine. Primary human hepatocytes are the gold standard for studying drug toxicity and metabolism; however, current technical limitations may slow down the large-scale diffusion of this cellular tool for in vitro investigations. To assess the potential hepatotoxicity of graphene oxide, we propose an alternative cell model, the second-generation upcyte^® hepatocytes, which show metabolic and functional profiles akin to primary human hepatocytes. Cells were acutely exposed to sub-lethal concentrations of graphene oxide (≤80 μg/ml) for 24 h and stress-related cell responses (such as apoptosis, oxidative stress, and inflammatory response) were evaluated, along with a broad investigation of graphene oxide impact on specialized hepatic functions. Results show a mild activation of early apoptosis but not oxidative stress or inflammatory response in our cell model. Notably, while graphene oxide clearly impacted phase-I drug-metabolism enzymes (e.g., CYP3A4, CYP2C9) through the inhibition of gene expression and metabolic activity, conversely, no effect was observed for phase-II enzyme GST and phase-III efflux transporter ABCG2. The GO-induced impairment of CYP3A4 occurs concomitantly with the activation of an early acute-phase response, characterized by altered levels of gene expression and protein production of relevant acute-phase proteins (i.e., CRP, Albumin, TFR, TTR). These data suggest that graphene oxide induces an acute phase response, which is in line with recent in vivo findings. In conclusion, upcyte^® hepatocytes appear a reliable in vitro model for assessing nanomaterial-induced hepatotoxicity, specifically showing that sub-lethal doses of graphene oxide have a negative impact on the specialized hepatic functions of these cells. The impairment of the cytochrome P450 system, along with the activation of an acute-phase response, may suggest potential detrimental consequences for human health, as altered detoxification from xenobiotics and drugs.

Stimulating effects of reduced graphene oxide on the growth and nitrogen fixation activity of nitrogen-fixing bacterium Azotobacter chroococcum

Graphene has found important applications in various areas and hundred tons of graphene materials are annually produced. It is crucial to investigate both the negative and positive environmental effects of graphene materials to ensure the safe applications and develop environmental applications. In this study, we reported the stimulating effects of reduced graphene oxide (RGO) to nitrogen-fixing bacterium Azotobacter chroococcum. RGO stimulated the cell growth of A. chroococcum at 0.010-0.500 mg/mL according to the growth curves and the colony-forming unit (CFU) increases. RGO wrapped over the A. chroococcum cells without inducing ultrastructural changes. RGO decreased the leakage of cell membrane, but slight oxidative stress was observed in A. chroococcum. RGO promoted the nitrogen fixation activity of A. chroococcum at 0.5 mg/mL according to both isotope dilution method and acetylene reduction activity measurements. Consequently, the increases of soil nitrogen contents were evidenced, in particular about 30% increase of organic nitrogen occurred at 0.5 mg/mL of RGO. In addition, RGO might possibly benefit the plant growth through enhancing the indoleacetic acid production of A. chroococcum. These results highlighted the positive environmental effects of graphene materials to nitrogen-fixing bacteria in nitrogen cycle.

Additive Manufactured Poly(ε-caprolactone)-graphene Scaffolds: Lamellar Crystal Orientation, Mechanical Properties and Biological Performance

Understanding the mechano-biological coupling mechanisms of biomaterials for tissue engineering is of major importance to assure proper scaffold performance in situ. Therefore, it is of paramount importance to establish correlations between biomaterials, their processing conditions, and their mechanical behaviour, as well as their biological performance. With this work, it was possible to infer a correlation between the addition of graphene nanoparticles (GPN) in a concentration of 0.25, 0.5, and 0.75% (w/w) (GPN0.25, GPN0.5, and GPN0.75, respectively) in three-dimensional poly(ε-caprolactone) (PCL)-based scaffolds, the extrusion-based processing parameters, and the lamellar crystal orientation through small-angle X-ray scattering experiments of extruded samples of PCL and PCL/GPN. Results revealed a significant impact on the scaffold's mechanical properties to a maximum of 0.5% of GPN content, with a significant improvement in the compressive modulus of 59 MPa to 93 MPa. In vitro cell culture experiments showed the scaffold's ability to support the adhesion and proliferation of L929 fibroblasts (fold increase of 28, 22, 23, and 13 at day 13 (in relation to day 1) for PCL, GPN0.25, GPN0.5, and GPN0.75, respectively) and bone marrow mesenchymal stem/stromal cells (seven-fold increase for all sample groups at day 21 in relation to day 1). Moreover, the cells maintained high viability, regular morphology, and migration capacity in all the different experimental groups, assuring the potential of PCL/GPN scaffolds for tissue engineering (TE) applications.

Progress in the Development of Graphene-Based Biomaterials for Tissue Engineering and Regeneration

Over the last few decades, tissue engineering has become an important technology for repairing and rebuilding damaged tissues and organs. The scaffold plays an important role and has become a hot pot in the field of tissue engineering. It has sufficient mechanical and biochemical properties and simulates the structure and function of natural tissue to promote the growth of cells inward. Therefore, graphene-based nanomaterials (GBNs), such as graphene and graphene oxide (GO), have attracted wide attention in the field of biomedical tissue engineering because of their unique structure, large specific surface area, good photo-thermal effect, pH response and broad-spectrum antibacterial properties. In this review, the structure and properties of typical GBNs are summarized, the progress made in the development of GBNs in soft tissue engineering (including skin, muscle, nerve and blood vessel) are highlighted, the challenges and prospects of the application of GBNs in soft tissue engineering have prospected.

Two-Dimensional Nanomaterials beyond Graphene for Biomedical Applications

Two-dimensional (2D) nanomaterials (e.g., graphene) have shown to have a high potential in future biomedical applications due to their unique physicochemical properties such as unusual electrical conductivity, high biocompatibility, large surface area, and extraordinary thermal and mechanical properties. Although the potential of graphene as the most common 2D nanomaterials in biomedical applications has been extensively investigated, the practical use of other nanoengineered 2D materials beyond graphene such as transition metal dichalcogenides (TMDs), topological insulators (TIs), phosphorene, antimonene, bismuthene, metal-organic frameworks (MOFs) and MXenes for biomedical applications have not been appreciated so far. This review highlights not only the unique opportunities of 2D nanomaterials beyond graphene in various biomedical research areas such as bioelectronics, imaging, drug delivery, tissue engineering, and regenerative medicine but also addresses the risk factors and challenges ahead from the medical perspective and clinical translation of nanoengineered 2D materials. In conclusion, the perspectives and future roadmap of nanoengineered 2D materials beyond graphene are outlined for biomedical applications.

Effects of the Surface Charge of Graphene Oxide Derivatives on Ocular Compatibility

The incorporation of functional groups endows graphene oxide (GO) with different surface charges, which plays important roles in biological interactions with cells. However, the effect of surface charge of GO derivatives on ocular biocompatibility has not been fully elucidated. Previously, we found that positively, negatively and neutrally charged PEGylated GO (PEG-GO) nanosheets exerted similar effect on the viability of ocular cells. In this work, we performed in vitro and in vivo studies to comprehensively study the effect of surface charge of PEG-GO on ocular compatibility. The in vitro results showed that the cellular uptake efficacy of negatively charged PEG-GO nanosheets was significantly decreased compared with positively charged and neutrally charged analogs. However, three kinds of PEG-GO nanosheets produced similar amounts of intracellular reactive oxygen species and showed similar influence on mitochondrial membrane potential. By analysis of global gene expression profiles, we found that the correlation coefficients between three kinds of PEG-GO-treated cells were more than 0.98. Furthermore, in vivo results showed that all these PEG-GO nanosheets had no significant toxicity to ocular structure and function. Taken together, our work suggested that surface charge of PEG-GO exerted negligible effect on its ocular compatibility, except for the cellular uptake. Our work is conducive to understanding the relationship between surface charge and biocompatibility of GO derivatives.

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.

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Development of GBNMs with unique structure and excellent properties.

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GBNMs-based therapies for anticancer with improved therapeutic efficacy.

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GBNMs with antimicrobial activity are widely used in anti-infections.

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The challenges and perspective of GBNMs for clinical use were thoroughly discussed.

Biomedical applications of chitosan-graphene oxide nanocomposites

Chitosan (CS) and graphene oxide (GO) nanocomposites have received wide attention in biomedical fields due to the synergistic effect between CS which has excellent biological characteristics and GO which owns great physicochemical, mechanical, and optical properties. Nanocomposites based on CS and GO can be fabricated into a variety of forms, such as nanoparticles, hydrogels, scaffolds, films, and nanofibers. Thanks to the ease of functionalization, the performance of these nanocomposites in different forms can be further improved by introducing other functional polymers, nanoparticles, or growth factors. With this background, the current review summarizes the latest developments of CS-GO nanocomposites in different forms and compositions in biomedical applications including drug and biomacromolecules delivery, wound healing, bone tissue engineering, and biosensors. Future improving directions and challenges for clinical practice are proposed as well.

Graphene quantum dots-porphyrins/phthalocyanines multifunctional hybrid systems: from interfacial dialogue to applications

Engineered well-ordered hybrid nanomaterials are at a symbolically pivotal point, just ahead of a long-anticipated human race transformation. Incorporating newer carbon nanomaterials like graphene quantum dots (GQDs) with tetrapyrrolic porphyrins...

Synthesis, Applications, and Prospects of Graphene Quantum Dots: A Comprehensive Review

Graphene quantum dot (GQD) is one of the youngest superstars of the carbon family. Since its emergence in 2008, GQD has attracted a great deal of attention due to its unique optoelectrical properties. Non-zero bandgap, the ability to accommodate functional groups and dopants, excellent dispersibility, highly tunable properties, and biocompatibility are among the most important characteristics of GQDs. To date, GQDs have displayed significant momentum in numerous fields such as energy devices, catalysis, sensing, photodynamic and photothermal therapy, drug delivery, and bioimaging. As this field is rapidly evolving, there is a strong need to identify the emerging challenges of GQDs in recent advances, mainly because some novel applications and numerous innovations on the ease of synthesis of GQDs are not systematically reviewed in earlier studies. This feature article provides a comparative and balanced discussion of recent advances in synthesis, properties, and applications of GQDs. Besides, current challenges and future prospects of these emerging carbon-based nanomaterials are also highlighted. The outlook provided in this review points out that the future of GQD research is boundless, particularly if upcoming studies focus on the ease of purification and eco-friendly synthesis along with improving the photoluminescence quantum yield and production yield of GQDs.

Nanotechnology: A Potential Weapon to Fight against COVID-19

The COVID-19 infections have posed an unprecedented global health emergency, with nearly three million deaths to date, and have caused substantial economic loss globally. Hence, an urgent exploration of effective and safe diagnostic/therapeutic approaches for minimizing the threat of this highly pathogenic coronavirus infection is needed. As an alternative to conventional diagnosis and antiviral agents, nanomaterials have a great potential to cope with the current or even future health emergency situation with a wide range of applications. Fundamentally, nanomaterials are physically and chemically tunable and can be employed for the next generation nanomaterial-based detection of viral antigens and host antibodies in body fluids as antiviral agents, nanovaccine, suppressant of cytokine storm, nanocarrier for efficient delivery of antiviral drugs at infection site or inside the host cells, and can also be a significant tool for better understanding of the gut microbiome and SARS-CoV-2 interaction. The applicability of nanomaterial-based therapeutic options to cope with the current and possible future pandemic is discussed here.