Cytotoxicity of graphene oxide and graphene in human erythrocytes and skin fibroblasts

Synergistic effects of polydopamine-coated reduced graphene oxide on osteogenesis and anti-inflammation in periodontitis

Owing to its extremely high prevalence and the distressing consequence of tooth loss, periodontitis has attracted substantial research attention. In light of these conditions, graphene-based biomaterials have emerged as a potentially promising approach for periodontal regeneration. This study focuses on the synthesis of polydopamine-coated reduced graphene oxide (RGO@PDA), designed to harness the anti-inflammatory properties of dopamine and the osteogenic potential of graphene oxide for synergistic periodontitis treatment. RGO@PDA was synthesized through a 12-h magnetic stirring process of graphene oxide and dopamine at room temperature. This water-dispersible and biocompatible compound demonstrated remarkable efficacy in enhancing osteogenic differentiation in rat bone mesenchymal stem cells (rBMSCs), evidenced by increased alkaline phosphatase activity, mineralization, and the upregulation of osteogenic genes and proteins. Furthermore, RGO@PDA showed significant capabilities in scavenging reactive oxygen species (ROS) and reducing proinflammatory factor expression. In vivo experiments revealed that RGO@PDA not only alleviated periodontal inflammation but also promoted alveolar bone repair in periodontitis-afflicted rats. These findings underscore RGO@PDA's dual anti-inflammatory and osteogenic effects, highlighting its potential as a transformative treatment for periodontitis.

Bi-functional carbonaceous hybrid nanocomposites with anticancer and antibacterial potential: synthesis, characterization, and cytotoxicity assessment

Infectious diseases and cancers are the leading causes of mortality worldwide. Despite the discovery of antimicrobials and anticancer drugs, the mortality rate has not declined significantly. Hence, new novel agents with antibacterial and anticancer properties without toxicity are urgently needed. In the present study, carbonaceous hybrid nanocomposites multi-walled carbon nanotubes (MWCNT)/hydroxyapatite (HAp)/polyetheretherketone (PEEK)-MWCNT/HAp/PEEK were synthesized using Alphie 3D Tumbler Mixer (Synthesis Method-1), solid-state mixing (Synthesis Method-2), and chemical mixing and solvent casting (Synthesis Method-3). Synthesis Method-2 and Method-3 exhibited antibacterial activities at 250 and 500 µg/mL concentrations, and no antibacterial activity in the nanocomposite fabricated by Synthesis Method-1. However, nanocomposites prepared by Synthesis Method-1 demonstrated enhanced anticancer activity compared to Synthesis Method-2 and Synthesis Method-3. Moreover, these nanocomposites did not show any haemolytic activity at 250 and 500 µg/mL concentrations. These nanocomposites were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and transmission electron microscopy (TEM). SEM data demonstrated that nanocomposites fabricated by Synthesis Method-3 were a homogeneous, defect-free PEEK matrix with well-dispersed MWCNTs and HAp compared to Methods-1 and 2. EDS analysis showed that Synthesis Methods-2 and -3 exhibited enhanced PEEK and MWCNT dispersion. TGA analysis exhibited that Synthesis Method-3 led to the highest thermal stability. FTIR data demonstrated the presence of various functional groups in hybrid nanocomposites. XRD analysis confirmed that these nanocomposites were crystalline in nature. The TEM analysis confirms that amine-functionalized MWCNTs and HAp nanoparticles are well dispersed within the PEEK matrix. In conclusion, the synthesis strategy adopted has influenced and resulted in safe and bi-functional nanocomposites having antibacterial and anticancer activity in line with SDG-3.

Nonequilibrium Solution-Based Assemblies from Bottlebrush Block Copolymers for Drug Delivery

Kinetic aspects of the self-assembly process of block copolymers are of great interest, as they can direct assembly through specific pathways, yielding nonequilibrium states with complex and unprecedented nanostructures. Assembly kinetics of diblock bottlebrushes was shown to influence the material properties of their solid-state nanostructures, yet little is known regarding their solution-based structures. Herein, we target the nonequilibrium self-assembly of nanoparticles from a zwitterionic diblock bottlebrush consisting of poly(d,l-lactide) and poly(2-methacryloyloxyethyl phosphorylcholine) side-chains. Triggered by a large and rapid change in solvent quality, we examine the resulting nonequilibrium structures (nanoparticles) and their equilibrium analogues (micelles). Using a combination of microscopy and light scattering methods as well as molecular simulations, we gain a microscopic understanding of the experimentally observed differences between the two systems. Compared to micelles, nanoparticles were observed to have a considerably lower aggregation number (accurately predicted by micellar evolution kinetics) and more frustrated core-block packing, along with a lower surface density of hydrophilic chains. Both types of assemblies possessed excellent hemocompatibility and colloidal stability under physiological conditions, concentrated salt solutions, and elevated temperature cycling. Encapsulation of a biopharmaceutics classification system (BCS) class II drug showed superior drug loading capacities and efficiencies for nanoparticles that were not achievable by micelles. In essence, this research provides insight regarding the effects of assembly and stabilization kinetics of zwitterionic bottlebrushes, laying the groundwork for future optimization as a drug delivery platform.

Biosafety and Blood Compatibility of Graphene Oxide Particles in In Vitro Experiments

Graphene oxide (GO), owing to its extraordinary application prospects in biomedicine, is attracting growing research attention. However, the biosafety and blood compatibility of GO required for its clearance for use in clinical trials remain elusive. Therefore, we studied the mutagenic properties of GO as well as its cell toxicity and blood compatibility. Prior to biological experiments, we assessed the structural organization of GO using dynamic light scattering and microscopic visualization methods. The results of both the Ames mutagenicity test performed on Salmonella enterica serovar Typhimurium TA98 and TA102 strains and the cytotoxicity test on noncancerous, immortalized human keratinocytes revealed no mutagenic or toxic effects of GO. Simultaneously, GO reduced the viability of the MelJuSo human melanoma cell line. A blood compatibility assay revealed that a concentration of 10 μg/mL was critical for GO biosafety, as greater concentrations induced diverse side effects. Specifically, GO disrupts erythrocytes' membranes in the dose-dependent manner. Moreover, GO at higher concentrations both inhibited the process of ADP (a physiological platelet agonist)-induced cell aggregation and affected their disaggregation process in platelet-rich plasma. However, in the blood clotting assessment, GO showed no effects on the activated partial thromboplastin time, prothrombin time, or thrombin time of the platelet-poor plasma. The obtained results clearly indicate that the relationship between the GO preparation method, its size, and concentration and biosafety must be cautiously monitored in the context of further possible biomedical applications.

Assessment of aqueous graphene as a cancer therapeutics delivery system

Graphene is a nanomaterial used in health and oncology settings. However, several reports have raised the alarm about potential toxicity. This study addressed this concern and determined the in vitro cytotoxicity of few-layer graphene (FLG) flakes produced in bespoke ultrasonic reactors using benign methods. The use of graphene flakes as a potential sensitising agent and a carrier for drug delivery in cancer cells was evaluated. To this end, aqueous based FLG suspensions were systematically characterised using UV-Vis, Raman spectroscopy and High-resolution Transmission electron microscopy (HR-TEM). Cell toxicity characterisation (e.g., cell viability assays using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and cell membrane integrity) of FLG in water were performed together with charge coupled device (CCD) and second harmonic generation (SHG) imaging of live cells in graphene solutions. Collectively, our findings show that NIH 3T3 mouse fibroblast and human fibroblast cells survival was higher than 80% and 90%, respectively upon treatment with the FLG fraction (~ 16 µg/ml ) recovered after centrifugation at 2000 revolutions per minute (RPM). In contrast, the cervical cancer cell line HeLa exposed to similar concentrations of FLG flakes resulted in approximately 30% cell death arguing in favour of a sensitising effect in cervical cancer cells.

Graphene-based materials are not skin sensitizers: adoption of the in chemico/in vitro OECD test guidelines

The boost in the market size of graphene-based materials (GBMs) requires a careful evaluation of their impact on human health, acquiring robust and reliable data, also suitable for regulatory purposes. Considering cutaneous contact as one of the most relevant GBM exposure routes, this study is focused on skin sensitization, aimed at assessing the possibility to adopt the three in chemico/in vitro test guidelines (TGs) defined by the Organization for Economic Cooperation and Development (442C, D and E) to predict the first three phases of the skin sensitization adverse outcome pathway. Being originally validated for chemicals, modifications allowing their adoption for GBMs were evaluated. TG 442C was found to be not suitable for testing GBMs due to their reactivity, leading to possible misclassifications. In contrast, TG 442D and E can generally be applied for GBMs. However, protocol adjustments were required to assess cell viability reducing interferences for TG 442D, whereas caution should be exercised regarding dose-finding selection and GBM dispersion stability for TG 442E. When applying these modifications, GBMs were found to be unable to activate keratinocytes and promote dendritic cell differentiation, so they can be considered non-sensitizers. Overall, these results significantly contribute to understanding the safety profiles of GBMs and to improve testing methodologies to obtain reliable toxicological data.

Covalent Peptide-Graphene Conjugates for Enhanced Cell Spreading, Osteogenic Differentiation, and Angiogenesis in Bone Defects

Traumatic bone injury is one of the most common injuries that require surgical intervention, and current treatments suffer severe drawbacks. Modern research in bone regeneration focuses on implants that will support and enhance native tissue regeneration. One scaffold material that shows promise is graphene oxide (GO), a 2D nanomaterial made from oxidation of graphite. GO is biocompatible, strong, osteoinductive, is safely and slowly resorbed by the body, has a cheap, facile, and scalable synthesis, and is highly tailorable and functionalizable. The bioactivity of GO can be enhanced via functionalization with biomolecules such as peptides, proteins, and small molecules. Here, short peptides RGD, DGEA, and KKGHK are covalently bound to GO through a Claisen modification (CG) to create new functional graphenic materials that are cell-adhesive, osteogenic, and angiogenic, respectively. These peptide-Claisen graphenes (peptide-CGs) are found to be cytocompatible, to encourage cell spreading on the graphenic surface, to promote osteogenesis in stem cells, and to induce angiogenesis in vascular endothelial cells. They show promise as next-generation bone regeneration scaffolds by overcoming challenges frequently faced by bone regeneration scaffolds, namely retaining implanted and recruited cells, promoting their survival, proliferation, and differentiation, and ensuring a sufficient oxygen and nutrient supply to new tissue.

The Role and Future of Functional Graphenic Materials in Biomedical and Human Health Applications

Functional graphenic materials (FGMs) are materials derived from graphene oxide (GO) that hold a plethora of applications from electronics to nanomedicine. In this Perspective, we examine the history and evolution of biomedical applications of this carbon-based macromolecule. Following the carbon nanotube (CNT) movement, GO and FGMs became nanocarbons of interest because of their low cost and versatile functionality. The tunable chemistry enabled our work on FGMs coupled with biomacromolecules and allows FGMs to plays an important role in many biomedical applications, from tissue regeneration to controlled delivery. As we work to develop this material, it is critical to consider toxicity implications─in fresh materials as well as in degradation products. With this understanding, FGMs also hold potential roles in human health and environmental sustainability, making FGMs an important contemporary biomacromolecule.

Biocompatibility of Water-Dispersible Pristine Graphene and Graphene Oxide Using a Close-to-Human Animal Model: A Pilot Study on Swine

Graphene-based materials (GBMs) are of considerable interest for biomedical applications, and the pilot study on the toxicological and immunological impact of pristine graphene (GR) and graphene oxide (GO) using swine as a close-to-human provides valuable insights. First, ex vivo experiments are conducted on swine blood cells, then GBMs are injected intraperitoneally (i.p.) into swine. Hematological and biochemical analyses at various intervals indicate that neither GO nor GR cause systemic inflammation, pro-coagulant responses, or renal or hepatic dysfunction. Importantly, no systemic toxicity is observed. Analysis of a panel of 84 immune-related genes shows minimal impact of GO and GR. The animals are sacrificed 21 days post-injection, and transient absorption imaging and Raman mapping show the presence of GO and GR in the mesentery only. Histological evaluation reveals no signs of alterations in other organs. Thus, clusters of both materials are detected in the mesentery, and GO aggregates are surrounded only by macrophages with the formation of granulomas. In contrast, modest local reactions are observed around the GR clusters. Overall, these results reveal that i.p. injection of GBMs resulted in a modest local tissue reaction without systemic toxicity. This study, performed in swine, provides essential guidance for future biomedical applications of graphene.

A Comprehensive Review on Bioprinted Graphene-Based Material (GBM)-Enhanced Scaffolds for Nerve Guidance Conduits

Peripheral nerve injuries (PNIs) pose significant challenges to recovery, often resulting in impaired function and quality of life. To address these challenges, nerve guidance conduits (NGCs) are being developed as effective strategies to promote nerve regeneration by providing a supportive framework that guides axonal growth and facilitates reconnection of severed nerves. Among the materials being explored, graphene-based materials (GBMs) have emerged as promising candidates due to their unique properties. Their unique properties-such as high mechanical strength, excellent electrical conductivity, and favorable biocompatibility-make them ideal for applications in nerve repair. The integration of 3D printing technologies further enhances the development of GBM-based NGCs, enabling the creation of scaffolds with complex architectures and precise topographical cues that closely mimic the natural neural environment. This customization significantly increases the potential for successful nerve repair. This review offers a comprehensive overview of properties of GBMs, the principles of 3D printing, and key design strategies for 3D-printed NGCs. Additionally, it discusses future perspectives and research directions that could advance the application of 3D-printed GBMs in nerve regeneration therapies.

Advanced Thermoactive Nanomaterials for Thermomedical Tissue Regeneration: Opportunities and Challenges

Nanomaterials usually possess remarkable properties, including excellent biocompatibility, unique physical and chemical characteristics, and bionic attributes, which make them highly promising for applications in tissue regeneration. Thermal therapy has emerged as a versatile approach for wound healing, nerve repair, bone regeneration, tumor therapy, and antibacterial tissue regeneration. By combining nanomaterials with thermal therapy, multifunctional nanomaterials with thermogenic effects and tissue regeneration capabilities can be engineered to achieve enhanced therapeutic outcomes. This study provides a comprehensive review of the effects of thermal stimulation on cellular and tissue regeneration. Furthermore, it highlights the applications of photothermal, magnetothermal, and electrothermal nanomaterials, and thermally responsive drug delivery systems in tissue engineering. In Addition, the bioactivities and biocompatibilities of several representative thermal nanomaterials are discussed. Finally, the challenges facing thermal nanomaterials are outlined, and future prospects in the field are presented with the aim of offering new opportunities and avenues for the utilization of thermal nanomaterials in tissue regeneration.

Synergistic effects of incorporated additives in multifunctional dressings for chronic wound healing: An updated comprehensive review

Detailed reviewing of the complicated process of wound healing reveals that it resembles an orchestrated symphony via a precise and calculated collaboration of relevant cells at the wound site. The domino-like function of various cytokines, chemokines, growth factors and small biological molecules such as antibacterial peptides all come together to successfully execute the wound healing process. Therefore, it appears that the use of a wound dressing containing only a single additive with specific properties and capabilities may not be particularly effective in treating the complex conditions that are usual in the environment of chronic wounds. The use of multifunctional dressings incorporating various additives has shown promising results in enhancing wound healing processes. This comprehensive review article explores the synergistic effects of integrated additives in such dressings, aiming to provide an updated understanding of their combined therapeutic potential. By analysing recent advancements and research findings, this review sheds light on the intricate interactions between different additives, their mechanisms of action and their cumulative impact on wound healing outcomes. Moreover, the review discusses the importance of utilising combined therapies in wound care and highlights the potential future directions and implications for research and clinical practice in the field of wound healing management.

Development of a two-dimensional peptide functionalized-reduced graphene oxide biomaterial for wound care applications

Increased incidences of antibiotic resistance have necessitated the development of novel wound disinfection strategies with minimal risk of resistance development. This study aimed at developing a biocompatible wound dressing biomaterial with the potential to treat acute and chronic wounds infected with multidrug-resistant Pseudomonas aeruginosa. A multifunctional antibacterial nanoconjugate was synthesized by covalently coupling a synthetically designed peptide (DP1, i.e., RFGRFLRKILRFLKK) with reduced graphene oxide (rGO). The conjugate displayed antibacterial and antibiofilm activities against multidrug-resistant Pseudomonas aeruginosa. In vitro studies demonstrated 94% hemocompatibility of the nanoconjugate even at concentrations as high as 512 μg mL-1. Cytotoxicity studies on 3T3-L1 cells showed 95% cell viability, signifying biocompatibility. Owing to these properties, the biomedical applicability of the nanoconjugate was assessed as an antibacterial wound dressing agent. rGO-DP1-loaded wound dressing exhibited enhanced reduction in bacterial bioburden (6 log 10 CFU) with potential for wound re-epithelization (77.3%) compared to the uncoated bandage. Moreover, an improvement in the material properties of the bandage was observed in terms of enhanced tensile strength and decreased elongation at break (%). Collectively, these findings suggest that rGO-DP1 is an effective biomaterial that, when loaded on wound dressings, has the potential to be used as a facile, sustainable and progressive agent for bacterial wound disinfection as well as healing.

Electrical stimulation and conductive materials: electrophysiology-based treatment for spinal cord injury

Spinal cord injury is a serious disease of the central nervous system. The electrophysiological properties of the spinal cord that are essential to maintaining neurotransmission can be impaired after the injury. Therefore, electrophysiological evaluation is becoming an important indicator of the injury extent or the therapeutic outcomes by reflecting the potential propagation of neural pathways. On the other hand, the repair of damaged nerves is one of the main goals of spinal cord injury treatment. Growing research interest has been concentrated on developing effective therapeutic solutions to restore the normal electrophysiological function of the injured spinal cord by using conductive materials and/or exerting the merits of electrical stimulation. Accordingly, this review introduces the current common electrophysiological evaluation in spinal cord injury. Then the cutting-edge therapeutic strategies aiming at electrophysiological improvement in spinal cord injury are summarized. Finally, the challenges and future prospects of neural restoration after spinal cord injury are presented.

The impact of print orientation and graphene nanoplatelets on biaxial flexural strength and cytotoxicity of a 3D printable resin for occlusal splints

OBJECTIVES

3D printing found its way into various medical applications and could be particularly beneficial for dentistry. Currently, materials for 3D printing of occlusal splints lack mechanical strength compared to polymethyl methacrylate (PMMA) used for standard milling of occlusal splints. It is known that print orientation and graphene nanoplatelets (GNP) can increase biaxial strength in a variety of materials. Thus, the aim of this study was to assess if adjustment of print orientation and addition of GNP improve biaxial strength and if they affect cytotoxicity of a 3D printable resin for occlusal splints.

METHODS

Specimens were printed vertically and horizontally with a stereolithography (SLA) printer and multilayered GNP powder was added to the resin at different concentrations. Printed specimens were characterized by Raman spectroscopy, optical profilometer analysis and scanning electron microscopy. Biaxial strength was evaluated by biaxial flexural testing. Cytotoxicity of specimens on L929 and gingival stromal cells (GSC) was assessed by the toxdent test, the resazurin-based toxicity assay and live-dead staining.

RESULTS

Horizontally printed specimens showed significantly higher biaxial strength and lower deformation. GNP did not improve biaxial strength and material deformation of 3D-printed resins. None of the specimens were cytotoxic to L929 cells or GSC.

SIGNIFICANCE

Print orientation in SLA printing has a significant impact on biaxial strength and material deformation. 3D printable materials can reach comparable or even improved biaxial strength compared to PMMA when using the optimal print orientation while GNP has no beneficial effects on the biaxial strength of resins for 3D printing of occlusal splints.

Ultrastable and Redispersible Zwitterionic Bottlebrush Micelles for Drug Delivery

Bottlebrush copolymers are increasingly used for drug delivery and biological imaging applications in part due to the enhanced thermodynamic stability of their self-assemblies. Herein, we discuss the effect of hydrophilic block chemistry on the stability of bottlebrush micelles. Amphiphilic bottlebrushes with zwitterionic poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) and nonionic polyethylene glycol (PEG) hydrophilic blocks were synthesized by "grafting from" polymerization and self-assembled into well-defined spherical micelles. Colloidal stability and stability against disassembly were challenged under high concentrations of NaCl, MgSO4, sodium dodecyl sulfate, fetal bovine serum, and elevated temperature. While both types of micelles appeared to be stable in many of these conditions, those with a PMPC shell consistently surpassed their PEG analogs. Moreover, when repeatedly subjected to lyophilization/resuspension cycles, PMPC micelles redispersed with no apparent variation in size or dispersity even in the absence of a cryoprotectant; PEG micelles readily aggregated. The observed excellent stability of PMPC micelles is attributed to the low critical micelle concentration of the bottlebrushes as well as to the strong hydration shell caused by ionic solvation of the phosphorylcholine moieties. Zwitterionic micelles were loaded with doxorubicin, and higher loading capacity/efficiency, as well as delayed release, was observed with increasing side-chain length. Finally, hemocompatibility studies of PMPC micelles demonstrated no disruption to the red blood cell membranes. The growing concern regarding the immunogenicity of PEG-based systems propels the search for alternative hydrophilic polymers; in this respect and for their outstanding stability, zwitterionic bottlebrush micelles represent excellent candidates for drug delivery and bioimaging applications.

Chitosan-based smart stimuli-responsive nanoparticles for gene delivery and gene therapy: Recent progresses on cancer therapy

Recent cancer therapy research has found that chitosan (Ch)-based nanoparticles show great potential for targeted gene delivery. Chitosan, a biocompatible and biodegradable polymer, has exceptional properties, making it an ideal carrier for therapeutic genes. These nanoparticles can respond to specific stimuli like pH, temperature, and enzymes, enabling precise delivery and regulated release of genes. In cancer therapy, these nanoparticles have proven effective in delivering genes to tumor cells, slowing tumor growth. Adjusting the nanoparticle's surface, encapsulating protective agents, and using targeting ligands have also improved gene delivery efficiency. Smart nanoparticles based on chitosan have shown promise in improving outcomes by selectively releasing genes in response to tumor conditions, enhancing targeted delivery, and reducing off-target effects. Additionally, targeting ligands on the nanoparticles' surface increases uptake and effectiveness. Although further investigation is needed to optimize the structure and composition of these nanoparticles and assess their long-term safety, these advancements pave the way for innovative gene-focused cancer therapies.

Graphene oxide nanoribbons conjugated with 1, 2-distearoyl-sn-glycero-3 phosphoethanolamine-poly (ethylene glycol)-transferrin enhanced targeted delivery and cytotoxicity of raloxifene against breast cancer

The clinical utility of raloxifene (RLX), a selective estrogen receptor modulator (SERM), has been compromised by severe side effects and unfavorable drug properties. To address these, a transferrin (Tf) conjugated graphene oxide nanoribbon (GONR) platform was tried for RLX. The stability of GONRs in biological media was improved by surface modification with 1, 2-Distearoyl-sn-glycero-3 phosphoethanolamine-Poly (ethylene glycol) (DSPE-PEG). The Tf molecule was covalently attached to DSPE-PEG (DPT) using EDC-NHS chemistry. The surface of GONR was then modified with DSPE-PEG (DP) or DPT and loaded with RLX (GDP-RLX and GDPT-RLX). The final formulations were characterized for drug loading and stability. The anticancer activities of pure RLX, GDP-RLX, and GDPT-RLX were evaluated and compared in all the in vitro and in vivo studies. In vitro cell line studies showed that GDPT-RLX have significantly high cytotoxicity, cellular uptake, apoptosis induction, G2/M phase arrest, anti-migration properties, and apoptotic protein expression, followed by GDP-RLX and RLX. Pharmacokinetics and tumor biodistribution were also found to be excellent with GDPT-RLX. The in vivo tumor therapy and tumor evaluation outcomes were also consistent with the in vitro data. The Tf conjugated GDPT-RLX represents a promising approach for targeted and sustained delivery of RLX with enhanced therapeutic efficacy.

Unravelling the toxicity of carbon nanomaterials - From cellular interactions to mechanistic understanding

The application of carbon nanomaterials in diverse fields has substantially increased their demand for commercial usage. Within the earliest decade, the development of functional materials has further increased the significance of this element. Despite the advancements recorded, the potential harmful impacts of embracing carbon nanomaterials for biological applications must be balanced against their advantages. Interestingly, many studies have neglected the intriguing and dynamic cellular interaction of carbon nanomaterials and the mechanistic understanding of their property-driven behaviour, even though common toxicity profiles have been reported. Reiterating the toxicity issue, several researchers conclude that these materials have minimal toxicity and may be safe for contact with biological systems at certain dosages. Here, we aim to provide a report on the significance of some of the properties that influence their toxicity. After that, a description of the implication of nanotoxicology in humans and living systems, revealing piece by piece their exposure routes and possible risks, will be provided. Then, an extensive discussion of the mechanistic puzzle modulating the interface between various human cellular systems and carbon nanomaterials such as carbon nanotubes, carbon dots, graphene, fullerenes, and nanodiamonds will follow. Finally, this review also sheds light on the organization that handles the risk associated with nanomaterials.

Graphene Quantum Dots from Natural Carbon Sources for Drug and Gene Delivery in Cancer Treatment

Cancer therapy is constantly evolving, with a growing emphasis on targeted and efficient treatment options. In this context, graphene quantum dots (GQDs) have emerged as promising agents for precise drug and gene delivery due to their unique attributes, such as high surface area, photoluminescence, up-conversion photoluminescence, and biocompatibility. GQDs can damage cancer cells and exhibit intrinsic photothermal conversion and singlet oxygen generation efficiency under specific light irradiation, enhancing their effectiveness. They serve as direct therapeutic agents and versatile drug delivery platforms capable of being easily functionalized with various targeting molecules and therapeutic agents. However, challenges such as achieving uniform size and morphology, precise bandgap engineering, and scalability, along with minimizing cytotoxicity and the environmental impact of their production, must be addressed. Additionally, there is a need for a more comprehensive understanding of cellular mechanisms and drug release processes, as well as improved purification methods. Integrating GQDs into existing drug delivery systems enhances the efficacy of traditional treatments, offering more efficient and less invasive options for cancer patients. This review highlights the transformative potential of GQDs in cancer therapy while acknowledging the challenges that researchers must overcome for broader application.

Cholesterol Based Organogelators in Environmental Remediation: Applications in Removal of Toxic Textile Dyes and Oil Spill Recovery

Oil spills in the ocean and textile dyes have a catastrophic impact on the environment, economy, and ecosystem. Phase-selective organic gelator dye sorption and oil separation for oil adsorption should meet certain criteria such as facile synthesis, low cost, effective gelation, and recyclability. This study has discovered that an aliphatic chain synthetic amphiphile based on cholesterol can produce organogels in a variety of organic solvents. Numerous methods, such as X-ray diffraction, Fourier-transform infrared spectroscopy, high-resolution scanning electron microscopy, and rheology, have been used extensively to examine and describe these organogels. An environmentally acceptable technique for achieving hazardous dye separation is presented here. For the sustainable filtration of dye-contaminated water, a new, straightforward, one-step method driven by gravitational force has been employed by using a gel column. This approach has shown excellent stability and reusability with repeated use, and it is easily scalable for the effective removal of a wide range of hazardous dyes. Furthermore, because the oil fraction was absorbed in the gel, the study showed how well it might be used to apply phase selectivity to separate the oil-water mixture from marine accidents. Furthermore, a straightforward distillation method can be used to quantitatively recover the oils contained in the gel and gelator molecules in phase-selective gelation. This low-tech, ecofriendly, and highly effective method also offers valuable insights into the development of advanced materials for separating toxic dyes and oil from water.

Involvement of ahr-dependent Cyp1a detoxification activity, oxidative stress and inflammatory regulation in response to graphene oxide exposure in rainbow trout (Oncorhynchus mykiss)

Graphene oxide (GO) is a very attractive material for use in a vast number of applications. However, before its widespread use, it is important to consider potential issues related to environmental safety to support its safe application. The aim of this study was to investigate effects on fish (rainbow trout) following GO exposure. Using both an in vitro approach with the RTL W1 rainbow trout liver cell line, and in vivo exposures, following OECD TG 203, disturbances at the cellular level as well as in the gills and liver tissue of juvenile trout were assessed. In RTL W1 cells, a time and concentration-dependent loss in cell viability, specifically plasma membrane integrity and lysosomal function, was observed after 96 h of exposure to GO at concentrations ≥18.75 mg/L. Additionally, increased reactive oxygen species (ROS) levels were evidenced at concentrations ≥18.75 mg/L, and an enhancement of metabolic activity was noted with concentrations ≥4.68 mg/L. In vivo exposures to GO did not provoke mortality in rainbow trout juveniles following 96 h exposure but led to histological alterations in gills and liver tissues, induction of enzymatic detoxification activities in the liver, as well as aryl hydrocarbon receptor (ahr)-cytochrome P450 1a (cyp1a) gene expression downregulation, and upregulation of pro-inflammatory cytokines il1b and il8 at GO concentrations ≥9.89 mg/L.

Light-Responsive and Antibacterial Graphenic Materials as a Holistic Approach to Tissue Engineering

While the continuous development of advanced bioprinting technologies is under fervent study, enhancing the regenerative potential of hydrogel-based constructs using external stimuli for wound dressing has yet to be tackled. Fibroblasts play a significant role in wound healing and tissue implants at different stages, including extracellular matrix production, collagen synthesis, and wound and tissue remodeling. This study explores the synergistic interplay between photothermal activity and nanomaterial-mediated cell proliferation. The use of different graphene-based materials (GBM) in the development of photoactive bioinks is investigated. In particular, we report the creation of a skin-inspired dressing for wound healing and regenerative medicine. Three distinct GBM, namely, graphene oxide (GO), reduced graphene oxide (rGO), and graphene platelets (GP), were rigorously characterized, and their photothermal capabilities were elucidated. Our investigations revealed that rGO exhibited the highest photothermal efficiency and antibacterial properties when irradiated, even at a concentration as low as 0.05 mg/mL, without compromising human fibroblast viability. Alginate-based bioinks alongside human fibroblasts were employed for the bioprinting with rGO. The scaffold did not affect the survival of fibroblasts for 3 days after bioprinting, as cell viability was not affected. Remarkably, the inclusion of rGO did not compromise the printability of the hydrogel, ensuring the successful fabrication of complex constructs. Furthermore, the presence of rGO in the final scaffold continued to provide the benefits of photothermal antimicrobial therapy without detrimentally affecting fibroblast growth. This outcome underscores the potential of rGO-enhanced hydrogels in tissue engineering and regenerative medicine applications. Our findings hold promise for developing game-changer strategies in 4D bioprinting to create smart and functional tissue constructs with high fibroblast proliferation and promising therapeutic capabilities in drug delivery and bactericidal skin-inspired dressings.

Graphene Quantum Dots Inhibit Lipid Peroxidation in Biological Membranes

Excessive reactive oxygen species (ROS) in cellular environments leads to oxidative stress, which underlies numerous diseases, including inflammatory diseases, neurodegenerative diseases, cardiovascular diseases, and cancer. Oxidative stress can be particularly damaging to biological membranes such as those found in mitochondria, which are abundant with polyunsaturated fatty acids (PUFAs). Oxidation of these biological membranes results in concomitant disruption of membrane structure and function, which ultimately leads to cellular dysfunction. Graphene quantum dots (GQDs) have garnered significant interest as a therapeutic agent for numerous diseases that are linked to oxidative stress. Specifically, GQDs have demonstrated an ability to protect mitochondrial structure and function under oxidative stress conditions. However, the fundamental mechanisms by which GQDs interact with membranes in oxidative environments are poorly understood. Here, we used C11-BODIPY, a fluorescent lipid oxidation probe, to develop quantitative fluorescence assays that determine both the extent and rate of oxidation that occurs to PUFAs in biological membranes. Based on kinetics principles, we have developed a generalizable model that can be used to assess the potency of antioxidants that scavenge ROS in the presence of biological membranes. By augmenting our fluorescence assays with 1H NMR spectroscopy, the results demonstrate that GQDs scavenge nascent hydroxyl and peroxyl ROS that interact with membranes and that GQDs are potent inhibitors of ROS-induced lipid oxidation in PUFA-containing biological membranes. The antioxidant potency of GQDs is comparable to or even greater than established antioxidant molecules, such as ascorbic acid and Trolox. This work provides mechanistic insights into the mitoprotective properties of GQDs under oxidative stress conditions, as well as a quantitative framework for assessing antioxidant interactions in biological membrane systems.

GO/Cu Nanosheet-Integrated Hydrogel Platform as a Bioactive and Biocompatible Scaffold for Enhanced Calvarial Bone Regeneration

Purpose

The treatment of craniofacial bone defects caused by trauma, tumors, and infectious and degenerative diseases is a significant issue in current clinical practice. Following the rapid development of bone tissue engineering (BTE) in the last decade, bioactive scaffolds coupled with multifunctional properties are in high demand with regard to effective therapy for bone defects. Herein, an innovative bone scaffold consisting of GO/Cu nanoderivatives and GelMA-based organic-inorganic hybrids was reported for repairing full-thickness calvarial bone defect.

Methods

In this study, motivated by the versatile biological functions of nanomaterials and synthetic hydrogels, copper nanoparticle (CuNP)-decorated graphene oxide (GO) nanosheets (GO/Cu) were combined with methacrylated gelatin (GelMA)-based organic-inorganic hybrids to construct porous bone scaffolds that mimic the extracellular matrix (ECM) of bone tissues by photocrosslinking. The material characterizations, in vitro cytocompatibility, macrophage polarization and osteogenesis of the biohybrid hydrogel scaffolds were investigated, and two different animal models (BALB/c mice and SD rats) were established to further confirm the in vivo neovascularization, macrophage recruitment, biocompatibility, biosafety and bone regenerative potential.

Results

We found that GO/Cu-functionalized GelMA/β-TCP hydrogel scaffolds exhibited evidently promoted osteogenic activities, M2 type macrophage polarization, increased secretion of anti-inflammatory factors and excellent cytocompatibility, with favorable surface characteristics and sustainable release of Cu2+. Additionally, improved neovascularization, macrophage recruitment and tissue integration were found in mice implanted with the bioactive hydrogels. More importantly, the observations of microCT reconstruction and histological analysis in a calvarial bone defect model in rats treated with GO/Cu-incorporated hydrogel scaffolds demonstrated significantly increased bone morphometric values and newly formed bone tissues, indicating accelerated bone healing.

Conclusion

Taken together, this BTE-based bone repair strategy provides a promising and feasible method for constructing multifunctional GO/Cu nanocomposite-incorporated biohybrid hydrogel scaffolds with facilitated osteogenesis, angiogenesis and immunoregulation in one system, with the optimization of material properties and biosafety, it thereby demonstrates great application potential for correcting craniofacial bone defects in future clinical scenarios.

Emergence of graphene as a novel nanomaterial for cardiovascular applications

Cardiovascular diseases (CDs) are the foremost cause of death worldwide. Several promising therapeutic methods have been developed for this approach, including pharmacological, surgical intervention, cell therapy, or biomaterial implantation since heart tissue is incapable of regenerating and healing on its own. The best treatment for heart failure to date is heart transplantation and invasive surgical intervention, despite their invasiveness, donor limitations, and the possibility of being rejected by the patient's immune system. To address these challenges, research is being conducted on less invasive and efficient methods. Consequently, graphene-based materials (GBMs) have attracted a great deal of interest in the last decade because of their exceptional mechanical, electrical, chemical, antibacterial, and biocompatibility properties. An overview of GBMs' applications in the cardiovascular system has been presented in this article. Following a brief explanation of graphene and its derivatives' properties, the potential of GBMs to improve and restore cardiovascular system function by using them as cardiac tissue engineering, stents, vascular bypass grafts,and heart valve has been discussed.

NanoGraphene Clot: A New Fibrinogen-Mimic Hemostatic Material

Trauma is the leading cause of death for adults under the age of 44. Internal bleeding remains a significant challenge in medical emergencies, necessitating the development of effective hemostatic materials that could be administered by paramedics before a patient is in the hospital and treated by surgeons. In this study, we introduce a graphene oxide (GO)-based PEGylated synthetic hemostatic nanomaterial with an average size of 211 ± 83 nm designed to target internal bleeding by mimicking the role of fibrinogen. Functionalization of GO-g-PEG with peptides derived from the α-chain of fibrinogen, such as GRGDS, or the γ-chain of fibrinogen, such as HHLGGAKQAGDV:H12, was achieved with peptide loadings of 72 ± 6 and 68 ± 15 μM, respectively. In vitro studies with platelet-rich plasma (PRP) under confinement demonstrated aggregation enhancement of 39 and 24% for GO-g-PEG-GRGDS and GO-g-PEG-H12, respectively, compared to buffer, while adenosine diphosphate (ADP) alone induced a 5% aggregation. Compared to the same materials in the absence of ADP, GO-g-PEG-GRGDS achieved a 47% aggregation enhancement, while GO-g-PEG-H12 a 25% enhancement. This is particularly important for injectable hemostats and highlights the fact that our nanographene-based materials can only act as hemostats in the presence of agonists, reducing the possibility of unwanted clotting during circulation. Further studies on collagen-coated wells under dynamic flow revealed statistically significant augmentation of PRP fluorescence signal using GRGDS- or H12-coated GO-g-PEG compared to controls. Hemolysis studies showed <1% lysis of red blood cells (RBCs) at the highest PEGylated nanographene concentration. Finally, whole human blood coagulation studies reveal faster and more pronounced clotting using our nanohemostats vs PBS control from 3 min and below (blood is clotted with 10% CaCl2 within 4-5 min), with the biggest differences to be shown at 2 and 1 min. At 1 min, the clot weight was found to be ∼45% of that between 4 and 5 min, while no clot was formed in PBS-treated blood. Reduction of CaCl2 to 5 and 3%, or utilization of prostaglandin E1, an anticoagulant, still leads to clots but of smaller weight. The findings highlight the potential of our fibrinogen-mimic PEGylated nanographene as a promising non-hemolytic injectable scaffold for targeting internal bleeding, offering insights into its platelet aggregation capabilities under confinement and under dynamic flow as well as its pronounced coagulation abilities.

Graphene Oxide Significantly Modifies Cardiac Parameters and Coronary Endothelial Reactivity in Healthy and Hypertensive Rat Hearts Ex Vivo

Interactions of graphene oxide (GO) with an ex vivo rat heart and its coronary vessels have not been studied yet. Moreover, the conflicting data on the "structure-properties" relationships do not allow for biomedical applications of GO. Herein, we study the impact of GO on the ex vivo isolated rat heart, normotensive and hypertensive, under the working heart and the constant-pressure perfusion (Langendorff) regimes. Four structural GO variants of the following initial morphology were used: few-layer (below 10-layer) GO1, O < 49%; predominantly single-layer GO2, O = 41-50%; 15-20-layer GO3, O < 11%; and few-layer (below 10-layer) NH4 +-functionalized GO4, O < 44%, N = 3-6%. The aqueous GO dispersions, sonicated and stabilized with bovine serum albumin in Krebs-Henseleit-like solution-uniformized in terms of the particle size-were eventually size-monodisperse as revealed by dynamic light scattering. To study the cardiotoxicity mechanisms of GO, histopathology, Raman spectroscopy, analysis of cardiac parameters (coronary and aortic flows, heart rate, aortic pressure), and nitric oxide (NO-)-dependent coronary flow response to bradykinin (blood-vessel-vasodilator) were used. GO1 (10 mg/L) exerted no effects on cardiac function and preserved an increase in coronary flow in response to bradykinin. GO2 (10 mg/L) reduced coronary flow, aortic pressure in normotensive hearts, and coronary flow in hypertensive hearts, and intensified the response to bradykinin in normal hearts. GO3 (10 mg/L) reduced all parameters in hypertensive hearts and coronary response to bradykinin in normal hearts. At higher concentrations (normotensive hearts, 30 mg/L), the coronary response to bradykinin was blocked. GO4 (10 mg/L) reduced the coronary flow in normal hearts, while for hypertensive hearts, all parameters, except the coronary flow, were reduced and the coronary response to bradykinin was blocked. The results showed that a low number of GO layers and high O-content were safer for normal and hypertensive rat hearts. Hypertensive hearts deteriorated easier upon perfusion with low-O-content GOs. Our findings support the necessity of strict control over the GO structure during organ perfusion and indicate the urgent need for personalized medicine in biomedical applications of GO.

Perilous paradigm of graphene oxide and its derivatives in biomedical applications: Insight to immunocompatibility

With advancements in nanotechnology and innovative materials, Graphene Oxide nanoparticles (GONP) have attracted lots of attention among the diverse types of nanomaterials owing to their distinctive physicochemical characteristics. However, the usage at scientific and industrial level has also raised concern to their toxicological interaction with biological system. Understanding these interactions is crucial for developing guidelines and recommendations for applications of GONP in various sectors, like biomedicine and environmental technologies. This review offers crucial insights and an in-depth analysis to the biological processes associated with GONP immunotoxicity with multiple cell lines including human whole blood cultures, dendritic cells, macrophages, and multiple cancer cell lines. The complicated interactions between graphene oxide nanoparticles and the immune system, are highlighted in this work, which reveals a range of immunotoxic consequences like inflammation, immunosuppression, immunostimulation, hypersensitivity, autoimmunity, and cellular malfunction. Moreover, the immunotoxic effects are also highlighted with respect to in vivo models like mice and zebrafish, insighting GO Nanoparticles' cytotoxicity. The study provides invaluable review for researchers, policymakers, and industrialist to understand and exploit the beneficial applications of GONP with a controlled measure to human health and the environment.

A microphysiological system for handling graphene related materials under flow conditions

The field of nanotechnology has developed rapidly in recent decades due to its broad applications in many industrial and biomedical fields. Notably, 2D materials such as graphene-related materials (GRMs) have been extensively explored and, as such, their safety needs to be assessed. However, GRMs tend to deposit quickly, present low stability in aqueous solutions, and adsorb to plastic materials. Consequently, traditional approaches based on static assays facilitate their deposition and adsorption and fail to recreate human physiological conditions. Organ-on-a-chip (OOC) technology could, however, solve these drawbacks and lead to the development of microphysiological systems (MPSs) that mimic the microenvironment present in human tissues. In light of the above, in the present study a microfluidic system under flow conditions has been optimised to minimise graphene oxide (GO) and few-layer graphene (FLG) adsorption and deposition. For that purpose, a kidney-on-a-chip was developed and optimised to evaluate the effects of exposure to GO and FLG flakes at a sublethal dose under fluid flow conditions. In summary, MPSs are an innovative and precise tool for evaluating the effects of exposure to GRMs and other type of nanomaterials.

Comparative toxicological analysis of two pristine carbon nanomaterials (graphene oxide and aminated graphene oxide) and their corresponding degraded forms using human in vitro models

Despite the wide application of graphene-based materials, the information of the toxicity associated to some specific derivatives such as aminated graphene oxide is scarce. Likewise, most of these studies analyse the pristine materials, while the available data regarding the harmful effects of degraded forms is very limited. In this work, the toxicity of graphene oxide (GO), aminated graphene oxide (GO-NH2), and their respective degraded forms (dGO and dGO-NH2) obtained after being submitted to high-intensity sonication was evaluated applying in vitro assays in different models of human exposure. Viability and ROS assays were performed on A549 and HT29 cells, while their skin irritation potential was tested on a reconstructed human epidermis model. The obtained results showed that GO-NH2 and dGO-NH2 substantially decrease cell viability in the lung and gastrointestinal models, being this reduction slightly higher in the cells exposed to the degraded forms. In contrast, this parameter was not affected by GO and dGO which, conversely, showed the ability to induce higher levels of ROS than the pristine and degraded aminated forms. Furthermore, none of the materials is skin irritant. Altogether, these results provide new insights about the potential harmful effects of the selected graphene-based nanomaterials in comparison with their degraded counterparts.

Graphene oxide as inhibitor on the hydrolysis of fats under simulated in vitro duodenal conditions

Obesity is a global pandemic, thus novel developments that reduce the absorption of fats is of interest. We have evaluated the effect of graphene oxide (GO) on the lipase catalyzed hydrolysis of fats (tributyrin, sunflower and olive oil) under simulated duodenal conditions. Results indicate that the presence of GO in the digestion mixture can inhibit lipase activity up to a 90% of the initial reaction rate, and this inhibition lasts even during 2 h of digestion. The inhibition mechanism seems non competitive and could be opposite to the effect of bile salts, although the direct interaction between GO and the enzyme cannot be discarded. The inhibition is found also in alimentary fats suggesting that GO could be a strong inhibitor for fat hydrolysis.

Applications of graphene oxide and reduced graphene oxide in advanced dental materials and therapies

The graphene family of nanomaterials acquired significant attention in the field of dentistry due to a range of interesting properties. Graphene oxide (GO) and reduced graphene oxide (rGO) are the major graphene derivatives that are widely used in dental applications. These derivatives exhibit excellent mechanical properties, superior biocompatibility, good antibacterial properties, extreme chemical stability, and favorable tribological characteristics, thus representing highly materials for dentistry. The amphiphilic nature of GO allows covalent and noncovalent modifications that are favorable for biomedical applications. Graphene can influence the differentiation of dental pulp stem cells (DPSCs) and enhance the properties of other biomaterials. Here, we review the dental applications of GO or rGO with regards to antimicrobial activity, therapeutic drug delivery, restorative dentistry, implants, pulp regeneration, bone regeneration, periodontal tissue regeneration, biosensors, and tooth whitening.

Screening 2D Materials for Their Nanotoxicity toward Nucleic Acids and Proteins: An In Silico Outlook

Since the discovery of graphene, two-dimensional (2D) materials have been anticipated to demonstrate enormous potential in bionanomedicine. Unfortunately, the majority of 2D materials induce nanotoxicity via disruption of the structure of biomolecules. Consequently, there has been an urge to synthesize and identify biocompatible 2D materials. Before the cytotoxicity of 2D nanomaterials is experimentally tested, computational studies can rapidly screen them. Additionally, computational analyses can provide invaluable insights into molecular-level interactions. Recently, various "in silico" techniques have identified these interactions and helped to develop a comprehensive understanding of nanotoxicity of 2D materials. In this article, we discuss the key recent advances in the application of computational methods for the screening of 2D materials for their nanotoxicity toward two important categories of abundant biomolecules, namely, nucleic acids and proteins. We believe the present article would help to develop newer computational protocols for the identification of novel biocompatible materials, thereby paving the way for next-generation biomedical and therapeutic applications based on 2D materials.

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.

Applications of nanomaterials in anti-VEGF treatment for ophthalmic diseases

Angiogenesis has been determined to be essential in the occurrence and metastasis of diabetic retinopathy (DR), age-related macular degeneration (AMD), retinal vein occlusion (RVO), choroidal neovascularization (CNV), retinopathy of prematurity (ROP), tumor, etc. However, the clinical use of anti-vascular endothelial growth factors (VEGF) drugs is currently limited due to its high cost, potential side effects, and need for repeated injections. In recent years, nanotechnology has shown promising results in inhibiting neovascularization and reducing reactive oxygen species (ROS) or inflammatory factors. Some nanomaterials can also act as vehicles for drug delivery, such as lipid nanoparticles and PLGA. The process of angiogenesis and its molecular mechanism are discussed in this article. At the same time, this study aims to systematically review the research progress of nanotechnology and offer more treatment options for neovascularization-related diseases in clinical ophthalmology.

Naringin and graphene oxide incorporated Moringa oleifera gum/poly(vinyl) alcohol patch for enhanced wound healing

Patients and healthcare systems stand to gain much from the use of substances that can accelerate wound healing. In this research work, a polymeric patch was fabricated using polymers like poly (vinyl alcohol) (PVA) and Moringa oleifera gum (MO) incorporated with graphene oxide (GO) and naringin (Nar) (drug). This study determined the impact of using PVA/MO/GO/Nar polymeric patch on wound healing via in vitro and in vivo investigations. Graphene oxide was synthesized by modified Hummer's method. The synthesized sample was characterized using XRD, FT-IR, RAMAN Spectroscopy, FESEM and HRTEM. Antibacterial analysis of the GO on four different bacteria was studied through well diffusion, colony count, growth curve and biofilm assay. Biocompatibility was analysed by haemolysis assay. The morphology, antibacterial activity, haemolysis assay, swelling, degradation, porosity, water vapour transmission rate, drug release, blood pump model, in-vitro scratch assay and MTT assay were analysed for the fabricated polymeric patches under in-vitro condition. The PVA/MO/GO/Nar patch has shown enhanced wound healing in in-vivo wound healing experiments on albino Wistar rats.

Effects of mechanical properties of carbon-based nanocomposites on scaffolds for tissue engineering applications: a comprehensive review

Mechanical properties, such as elasticity modulus, tensile strength, elongation, hardness, density, creep, toughness, brittleness, durability, stiffness, creep rupture, corrosion and wear, a low coefficient of thermal expansion, and fatigue limit, are some of the most important features of a biomaterial in tissue engineering applications. Furthermore, the scaffolds used in tissue engineering must exhibit mechanical and biological behaviour close to the target tissue. Thus, a variety of materials has been studied for enhancing the mechanical performance of composites. Carbon-based nanostructures, such as graphene oxide (GO), reduced graphene oxide (rGO), carbon nanotubes (CNTs), fibrous carbon nanostructures, and nanodiamonds (NDs), have shown great potential for this purpose. This is owing to their biocompatibility, high chemical and physical stability, ease of functionalization, and numerous surface functional groups with the capability to form covalent bonds and electrostatic interactions with other components in the composite, thus significantly enhancing their mechanical properties. Considering the outstanding capabilities of carbon nanostructures in enhancing the mechanical properties of biocomposites and increasing their applicability in tissue engineering and the lack of comprehensive studies on their biosafety and role in increasing the mechanical behaviour of scaffolds, a comprehensive review on carbon nanostructures is provided in this study.

Gold nanoparticle adsorption alters the cell stiffness and cell wall bio-chemical landscape of Candida albicans fungal cells

HYPOTHESIS

Nanomaterials have been extensively investigated for a wide range of biomedical applications, including as antimicrobial agents, drug delivery vehicles, and diagnostic devices. The commonality between these biomedical applications is the necessity for the nanoparticle to interact with or pass through the cellular wall and membrane. Cell-nanomaterial interactions/uptake can occur in various ways, including adhering to the cell wall, forming aggregates on the surface, becoming absorbed within the cell wall itself, or transversing into the cell cytoplasm. These interactions are common to mammalian cells, bacteria, and yeast cells. This variety of interactions can cause changes to the integrity of the cell wall and the cell overall, but the precise mechanisms underpinning such interactions remain poorly understood. Here, we investigate the interaction between commonly investigated gold nanoparticles (AuNPs) and the cell wall/membrane of a model fungal cell to explore the general effects of interaction and uptake.

EXPERIMENTS

The interactions between 100 nm citrate-capped AuNPs and the cell wall of Candida albicans fungal cells were studied using a range of advanced microscopy techniques, including atomic force microscopy, confocal laser scanning microscopy, scanning electron microscopy, transmission electron microscopy, and synchrotron-FTIR micro-spectroscopy.

FINDINGS

In most cases, particles adhered on the cell surface, although instances of particles being up-taken into the cell cytoplasm and localised within the cell wall and membrane were also observed. There was a measurable increase in the stiffness of the fungal cell after AuNPs were introduced. Analysis of the synchrotron-FTIR data showed significant changes in spectral features associated with phospholipids and proteins after exposure to AuNPs.

Nanotechnology-Based Approaches for Cosmeceutical and Skin Care: A Systematic Review

Cosmeceuticals have gained great importance and are among the top-selling products used for skin care. Because of changing lifestyles, climate, and increasing pollution, cosmeceuticals are utilized by every individual, thereby making cosmeceuticals a fruitful field for research and the economy. Cosmeceuticals provide incredibly pleasing aesthetic results by fusing the qualities of both cosmetics and medicinal substances. Cosmeceuticals are primarily utilized to improve the appearance of skin by making it smoother, moisturized, and wrinkle-free, in addition to treating dermatological conditions, including photoaging, burns, dandruff, acne, eczema, and erythema. Nanocosmeceuticals are cosmetic products that combine therapeutic effects utilizing nanotechnology, allowing for more precise and effective target-specific delivery of active ingredients, and improving bioavailability.

Graphene-based nanomaterials for peripheral nerve regeneration

Emerging nanotechnologies offer numerous opportunities in the field of regenerative medicine and have been widely explored to design novel scaffolds for the regeneration and stimulation of nerve tissue. In this review, we focus on peripheral nerve regeneration. First, we introduce the biomedical problem and the present status of nerve conduits that can be used to guide, fasten and enhance regeneration. Then, we thoroughly discuss graphene as an emerging candidate in nerve tissue engineering, in light of its chemical, tribological and electrical properties. We introduce the graphene forms commonly used as neural interfaces, briefly review their applications, and discuss their potential toxicity. We then focus on the adoption of graphene in peripheral nervous system applications, a research field that has gained in the last years ever-increasing attention. We discuss the potential integration of graphene in guidance conduits, and critically review graphene interaction not only with peripheral neurons, but also with non-neural cells involved in nerve regeneration; indeed, the latter have recently emerged as central players in modulating the immune and inflammatory response and accelerating the growth of new tissue.

The recent development of carbon-based nanoparticles as a novel approach to skin tissue care and management - A review

Since the skin is the first barrier of the body's defense against pathogens, delays in the healing process are affected by infections. Therefore, applying advanced substitute assistance improves the patient's quality of life. Carbon-based nanomaterials show better capabilities than conventional methods for managing skin wound infections. Due to their physicochemical properties such as small size, large surface area, great surface-to-volume ratio, and excellent ability to communicate with the cells and tissue, carbon-based nanoparticles have been considered in regenerative medicine. moreover, the carbon nano family offers attractive potential in wound healing via the improvement of angiogenesis and antibacterial compared to traditional approaches become one of the particular research interests in the field of skin tissue engineering. This review emphasizes the wound-healing process and the role of carbon-based nanoparticles in wound care management interaction with tissue engineering technology.

Characteristics and Key Features of Antimicrobial Materials and Associated Mechanisms for Diverse Applications

Since the Fourth Industrial Revolution, three-dimensional (3D) printing has become a game changer in manufacturing, particularly in bioengineering, integrating complex medical devices and tools with high precision, short operation times, and low cost. Antimicrobial materials are a promising alternative for combating the emergence of unforeseen illnesses and device-related infections. Natural antimicrobial materials, surface-treated biomaterials, and biomaterials incorporated with antimicrobial materials are extensively used to develop 3D-printed products. This review discusses the antimicrobial mechanisms of different materials by providing examples of the most commonly used antimicrobial materials in bioengineering and brief descriptions of their properties and biomedical applications. This review will help researchers to choose suitable antimicrobial agents for developing high-efficiency biomaterials for potential applications in medical devices, packaging materials, biomedical applications, and many more.

Evaluating Gelatin-Based Films with Graphene Nanoparticles for Wound Healing Applications

In this study, gelatin-based films containing graphene nanoparticles were obtained. Nanoparticles were taken from four chosen commercial graphene nanoplatelets with different surface areas, such as 150 m2/g, 300 m2/g, 500 m2/g, and 750 m2/g, obtained in different conditions. Their morphology was observed using SEM with STEM mode; porosity, Raman spectra and elemental analysis were checked; and biological properties, such as hemolysis and cytotoxicity, were evaluated. Then, the selected biocompatible nanoparticles were used as the gelatin film modification with 10% concentration. As a result of solvent evaporation, homogeneous thin films were obtained. The surface's properties, mechanical strength, antioxidant activity, and water vapor permeation rate were examined to select the appropriate film for biomedical applications. We found that the addition of graphene nanoplatelets had a significant effect on the properties of materials, improving surface roughness, surface free energy, antioxidant activity, tensile strength, and Young's modulus. For the most favorable candidate for wound dressing applications, we chose a gelatin film containing nanoparticles with a surface area of 500 m2/g.

Graphene Oxide/Cholesterol-Substituted Zinc Phthalocyanine Composites with Enhanced Photodynamic Therapy Properties

In the present work, cholesterol (Chol)-substituted zinc phthalocyanine (Chol-ZnPc) and its composite with graphene oxide (GO) were prepared for photodynamic therapy (PDT) applications. Briefly, Chol-substituted phthalonitrile (Chol-phthalonitrile) was synthesized first through the substitution of Chol to the phthalonitrile group over the oxygen bridge. Then, Chol-ZnPc was synthesized by a tetramerization reaction of Chol-phthalonitrile with ZnCl2 in a basic medium. Following this, GO was introduced to Chol-ZnPc, and the successful preparation of the samples was verified through FT-IR, UV-Vis, 1H-NMR, MALDI-TOF MS, SEM, and elemental analysis. Regarding PDT properties, we report that Chol-ZnPc exhibited a singlet oxygen quantum yield (Φ∆) of 0.54, which is slightly lower than unsubstituted ZnPc. Upon introduction of GO, the GO/Chol-ZnPc composite exhibited a higher Φ∆, about 0.78, than that of unsubstituted ZnPc. Moreover, this enhancement was realized with a simultaneous improvement in fluorescence quantum yield (ΦF) to 0.36. In addition, DPPH results suggest low antioxidant activity in the composite despite the presence of GO. Overall, GO/Chol-ZnPc might provide combined benefits for PDT, particularly in terms of image guidance and singlet oxygen generation.

Background-filtered telomerase activity assay with cyclic DNA cleavage amplification

Overexpression of telomerase incites the abnormal proliferation of cancer cells. Thus, it has been regarded as a cancer biomarker and a potential therapeutic target. Existing assays suggest a promising sensing scheme to detect telomerase activity. However, they are complicated in terms of assay preparation and implementation. We herein report a Quenching-Exempt invader Signal Amplification Test, termed 'QUEST'. The assay leverages on a high turnover, specific cleaving enzyme, flap endonuclease I (FEN1), and graphene oxide (GO) for background (BG) filtering. In response to the target, FEN1 significantly boosts the signal with invader signal amplification. To distinguish the target signal, GO filters out the BG. It captures residual reporter invader probes (RP) to quench undesired signals. QUEST is straightforward without any pre-preparatory steps and washing/separation. Its probe design is simple and cost-effective. With QUEST, we investigated telomerase activities in various cell lines. Notably, we discriminated cancer cell lines from normal cell lines. In addition, a candidate inhibitor for telomerase was screened, which showed the promising potential of QUEST in real applications.

Efficient skin interactions of graphene derivatives: challenge, opportunity or both?

Interactions between graphene, with its wide deployment in consumer products, and skin, the body's largest organ and first barrier, are highly relevant with respect to toxicology and dermal delivery. In this work, interaction of polyglycerol-functionalized graphene sheets, with 200 nm average lateral size and different surface charges, and human skin was studied and their potential as topical delivery systems were investigated. While neutral graphene sheets showed no significant skin interaction, their positively and negatively charged counterparts interacted with the skin, remaining in the stratum corneum. This efficient skin interaction bears a warning but also suggests a new topical drug delivery strategy based on the sheets' high loading capacity and photothermal property. Therefore, the immunosuppressive drug tacrolimus was loaded onto positively and negatively charged graphene sheets, and its release measured with and without laser irradiation using liquid chromatography tandem-mass spectrometry. Laser irradiation accelerated the release of tacrolimus, due to the photothermal property of graphene sheets. In addition, graphene sheets with positive and negative surface charges were loaded with Nile red, and their ability to deliver this cargo through the skin was investigated. Graphene sheets with positive surface charge were more efficient than the negatively charged ones in enhancing Nile red penetration into the skin.

Adenylate kinase immobilized on graphene oxide impairs progression of human lung carcinoma epithelial cells through adenosinergic pathway

Purinergic signaling, the oldest evolutionary transmitter system, has been increasingly studied as a pivotal target for novel anti-cancer therapies. In the present work, the developed nanobiocatalytic system consisting of adenylate kinase immobilized on graphene oxide (AK-GO) was characterized in terms of its physicochemical and biochemical properties. We put special emphasis on the AK-GO influence on purinergic signaling components, that is, ecto-nucleotides concentration and ecto-enzymes expression and activity in human lung carcinoma epithelial (A549) cells. The immobilization-dependent modification of AK kinetic parameters allowed for the removal of ATP excess while maintaining low ATP concentrations, efficient decrease in adenosine concentration, and control of the nucleotide balance in carcinoma cells. The cyto- and hemocompatibility of developed AK-GO nanobiocatalytic system indicates that it can be successfully harnessed for biomedical applications. In A549 cells treated with AK-GO nanobiocatalytic system, the significantly decreased adenosinergic signaling results in reduction of the proliferation and migration capability of cancer cells. This finding is particularly relevant in regard to AK-GO prospective anti-cancer applications.