Comprehensive utilization and biomedical application of MXenes - A systematic review of cytotoxicity and biocompatibility

Bio-Functionalized MXenes: Synthesis and Versatile Applications

MXenes exhibit remarkable properties, including high electrical conductivity, tunable surface chemistry, outstanding mechanical strength, and notable hydrophilicity. Recent advancements in bio-functionalization have further enhanced these intrinsic characteristics, unlocking unprecedented opportunities for MXenes across a wide spectrum of applications in both biomedical and environmental domains. This review provides an in-depth analysis of the synthesis strategies and functionalization techniques that improve MXenes' biocompatibility and expand their potential uses in cutting-edge applications, including implantable and wearable devices, drug delivery systems, cancer therapies, tissue engineering, and advanced sensing technologies. Moreover, the review explores the utility of bio-functionalized MXenes in areas such as corrosion protection, water purification, and food safety sensors, underscoring their versatility in addressing urgent global challenges. By conducting a critical evaluation of current research, this review not only highlights the immense potential of bio-functionalized MXenes but also identifies pivotal gaps in the literature, offering clear pathways for future exploration and innovation in this rapidly evolving field.

MXene and prostate cancer: is there promising news?

Prostate cancer is the most prevalent cancer among men worldwide, and there have been many advances in its diagnosis and treatment. However, critical obstacles remain, including overdiagnosis, high rates of negative biopsies, management of side effects, and the timely detection of relapse. Despite these improvements, surgery and radiotherapy are still associated with a significant risk of short- or long-term side effects. MXenes are a novel class of two-dimensional nanomaterials manufactured through electrochemical procedures that accept a wide-termination of hydrophilic molecules as surface modifications. The importance of MXene has increased owing to many aspects, such as its high-gain synthesis potential, chemical flexibility, and high biocompatibility. Hence, MXene is a convenient nanomaterial that can be modified and synthesized in different models, suggesting its ability to improve screening, diagnosis, and theranostic applications, such as thermal therapy. These features have been used to detect potential urothelial tumor markers as well as the direction and accumulation of cancer medications in the target tissue.

Unravelling the Biomolecular Interactions Between Hemoglobin and 2D MXenes: A Breakthrough in Biomedical Approach

Taking the potential applications of two-dimensional transition metal carbides, such as MXenes, in biomedical fields, it is crucial to explore the impact of MXenes on various blood proteins. The study of the interaction of these 2D materials with proteins is scarce. Owing to the potential of absorbing proteins on the MXene surface, it is crucial to investigate the biocompatibility of these materials with proteins . In this regard, we successfully investigated the biomolecular interactions between hemoglobin (Hb) and single-layered titanium carbide (Ti3C2Tx-SL), multilayered titanium carbide (Ti3C2Tx-ML), and multilayered vanadium carbide (V2CTx-ML) MXenes for protein-MXene corona formation. The conformational, thermal, and colloidal stabilities of Hb were investigated after exposing MXenes to Hb for 30 min at Hb/MXene ratios of 12:1, 10:1, 8:1, and 6:1 using a combination of spectroscopic techniques, electron microscopy, and thermodynamic stability studies. Our results reveal that Hb adsorption onto MXene surfaces is primarily driven by electrostatic interactions and hydrogen bonding, leading to significant changes in the secondary and tertiary structures of the protein and further disruption in the colloidal stability of Hb. Explicitly, the hierarchy of interactions between Hb and MXenes follows the order: Ti3C2Tx-SL > V2CTx-ML > Ti3C2Tx-ML. The morphological study of Hb with MXenes was studied through transmission electron microscopy (TEM) and atomic force microscopy (AFM). Further, it was found that at high loading concentrations that is above 8:1, the protein-corona formation tendency of Hb-MXene also increases. The biological and toxicological behavior of nanomaterials (NMs) is based on the effect of their interaction with proteins, which induces conformational changes in proteins and subsequently alters their biological functions. In this regard, this article provides important insights for using these MXenes biomedically and for the rational design of nanoproducts based on MXenes in the near future.

Smart MXene-based microrobots for targeted drug delivery and synergistic therapies

MXenes and their composites exhibit remarkable electrical conductivity, mechanical flexibility, and biocompatibility, making them ideal candidates for microrobot fabrication. Their tunable surface chemistry allows for easy functionalization, which enhances their interaction with biological environments, thereby facilitating targeted therapies. Such smart microrobots can be engineered to navigate through complex biological systems with precision via the integration of responsive elements, such as stimuli-sensitive polymers or magnetic components. MXene-based microrobots are able to actively seek out specific tissues or cells. This capability is crucial for applications in cancer treatment, where localized drug delivery minimizes side effects and enhances therapeutic efficacy. The primary advantage of MXene-based microrobots lies in their ability to deliver therapeutic agents directly to diseased cells. Utilizing ligand-receptor interactions, these microrobots can bind to target cells and release their payload in a controlled manner. This targeted delivery system not only improves the effectiveness of the drug but also reduces the required dosage, thus mitigating potential side effects. Moreover, smart MXene-based microrobots can facilitate synergistic therapies by co-delivering multiple therapeutic agents. For instance, combining chemotherapy drugs with immunotherapeutic agents could enhance treatment outcomes in cancer therapy. The ability to simultaneously deliver different types of drugs allows for more comprehensive treatment strategies that can tackle tumor heterogeneity. Significant advancements are anticipated in synergistic therapies, particularly in chemo-photothermal, chemodynamic, and photothermal/photodynamic therapies. These strategies leverage multiple therapeutic modalities to enhance cancer treatment outcomes. Despite their outstanding potential, several challenges remain in the development of MXene-based microrobots namely matters pertaining to scalability, stability in biological environments, and associated regulatory hurdles which ought to be addressed. Future research should focus on optimizing the design and functionality of these microrobots, including enhancing their navigation capabilities and ensuring their safety and effectiveness in vivo. By presenting the innovative capabilities of MXene-based microrobots, this perspective aims to inspire additional explorations in the field of advanced targeted drug delivery systems and synergistic therapies, ultimately contributing to the future of personalized medicine and oncology.

Advances in conducting nanocomposite hydrogels for wearable biomonitoring

Recent advancements in wearable biosensors and bioelectronics have led to innovative designs for personalized health management devices, with biocompatible conducting nanocomposite hydrogels emerging as a promising building block for soft electronics engineering. In this review, we provide a comprehensive framework for advancing biosensors using these engineered nanocomposite hydrogels, highlighting their unique properties such as high electrical conductivity, flexibility, self-healing, biocompatibility, biodegradability, and tunable architecture, broadening their biomedical applications. We summarize key properties of nanocomposite hydrogels for thermal, biomechanical, electrophysiological, and biochemical sensing applications on the human body, recent progress in nanocomposite hydrogel design and synthesis, and the latest technologies in developing flexible and wearable devices. This review covers various sensor types, including strain, physiological, and electrochemical sensors, and explores their potential applications in personalized healthcare, from daily activity monitoring to versatile electronic skin applications. Furthermore, we highlight the blueprints of design, working procedures, performance, detection limits, and sensitivity of these soft devices. Finally, we address challenges, prospects, and future outlook for advanced nanocomposite hydrogels in wearable sensors, aiming to provide a comprehensive overview of their current state and future potential in healthcare applications.

Innovative applications of MXenes in dialysis: enhancing filtration efficiency

MXenes, a family of two-dimensional transition metal carbides and nitrides, exhibit exceptional properties such as high electrical conductivity, large surface area, and chemical versatility, making them ideal candidates for various dialysis applications. One prominent application of MXenes lies in the efficient removal of toxic metals and harmful dyes from wastewater. Their unique structure allows for rapid adsorption and selective separation, significantly improving purification processes. MXenes show great promise in the therapeutic management of acute kidney injury, where their biocompatibility and ability to facilitate toxin removal can mitigate damage to renal tissues. In hemodialysis, MXenes can enhance membrane performance through improved permeability and selectivity, leading to more effective clearance of waste products. Despite the potential of MXene-based composites in dialysis applications, several challenges loom large on the horizon. The stability of MXenes in physiological environments is a critical concern, as they can undergo oxidation or degradation, which may compromise their functionality over time. The scalability of synthesis processes remains a significant barrier; producing high-quality MXene materials in sufficient quantities for clinical use is not yet fully realized. Moreover, ensuring biocompatibility is paramount, as any adverse reactions could lead to inflammation or other complications in patients. The integration of MXenes into existing dialysis systems requires meticulous engineering to maintain optimal filtration properties while avoiding clogging or fouling. The future of MXenes and their composites in dialysis presents a promising horizon, teeming with potential innovations. The development of hybrid materials that utilize MXenes alongside other nanomaterials can lead to multifunctional systems, capable of addressing multiple challenges faced in dialysis treatments. Advancements in fabrication techniques may allow for tailored porosity, enabling customized dialysis solutions for individual patients. Research into surface modifications and composites can enhance their stability and functionality, potentially overcoming current limitations. The purpose of this review is to provide a comprehensive understanding of the current landscape of MXenes in dialysis, highlighting their applications, challenges, and future directions. This review explores the diverse applications of MXenes in the field of dialysis, focusing on their roles in the removal of toxic metals and dyes, therapy for acute kidney injury, and hemodialysis enhancement.

Isolation of Biomolecules Using MXenes

Biomolecule isolation is a crucial process in diverse biomedical and biochemical applications, including diagnostics, therapeutics, research, and manufacturing. Recently, MXenes, a novel class of two-dimensional nanomaterials, have emerged as promising adsorbents for this purpose due to their unique physicochemical properties. These biocompatible and antibacterial nanomaterials feature a high aspect ratio, excellent conductivity, and versatile surface chemistry. This timely review explores the potential of MXenes for isolating a wide range of biomolecules, such as proteins, nucleic acids, and small molecules, while highlighting key future research trends and innovative applications poised to transform the field. This review provides an in-depth discussion of various synthesis methods and functionalization techniques that enhance the specificity and efficiency of MXenes in biomolecule isolation. In addition, the mechanisms by which MXenes interact with biomolecules are elucidated, offering insights into their selective adsorption and customized separation capabilities. This review also addresses recent advancements, identifies existing challenges, and examines emerging trends that may drive the next wave of innovation in this rapidly evolving area.

Environmental and biomedical applications of 2D transition metal borides (MBenes): recent advancements

Recently, interest has surged in the environmental and biomedical applications of two-dimensional transition metal borides, commonly referred to as MBenes. These materials have emerged as promising candidates for energy storage devices, such as batteries and supercapacitors. Additionally, MBenes have shown remarkable catalytic activity due to their high surface area and tunable electronic properties. They exhibit significant promise in various catalytic applications, particularly in nitrogen reduction reactions (NRRs), electrocatalytic conversion of nitrogen oxides, and several electrochemical reactions such as the oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and hydrogen evolution reaction (HER). Notably, MBenes have shown great potential in water treatment and pollutant removal applications, such as desalination and water purification. Their high water permeability, ion selectivity, and excellent stability make them suitable for efficient water treatment processes. On the other hand, MBenes are emerging as versatile materials with significant potential in various biomedical applications, particularly in biosensing, cancer therapy, and the treatment of neurodegenerative diseases. However, several challenges hinder their practical implementation in biomedical and environmental fields. One significant issue is the scalability of synthesis methods; producing MBenes in large quantities while maintaining high purity and uniformity is often complex and costly. Moreover, the stability of MBenes and their composites under different environmental and biological conditions raises concerns, as they may undergo degradation or lose their functional properties over time, which could limit their long-term effectiveness. Additionally, there is a need for comprehensive toxicity assessments to ensure the safety of MBenes in biomedical applications, particularly when interacting with human tissues or biological systems. This review aims to systematically investigate the environmental and biomedical applications of MBenes and their composites, emphasizing their unique characteristics and potential roles in addressing pressing global challenges. Furthermore, the review will identify and discuss the existing challenges and limitations in the operational performance of MBenes and their composites, providing a critical assessment of their current state in various applications.

MXenes and artificial intelligence: fostering advancements in synthesis techniques and breakthroughs in applications

This review explores the synergistic relationship between MXenes and artificial intelligence (AI), highlighting recent advancements in predicting and optimizing the properties, synthesis routes, and diverse applications of MXenes and their composites. MXenes possess fascinating characteristics that position them as promising candidates for a variety of technological applications, including energy storage, sensors/detectors, actuators, catalysis, and neuromorphic systems. The integration of AI methodologies provides a robust toolkit to tackle the complexities inherent in MXene research, facilitating property predictions and innovative applications. We discuss the challenges associated with the predictive capabilities for novel properties of MXenes and emphasize the necessity for sophisticated AI models to unravel the intricate relationships between structural features and material behaviors. Moreover, we examine the optimization of synthesis routes for MXenes through AI-driven approaches, underscoring the potential for streamlining and enhancing synthesis processes via data-driven insights. Furthermore, the role of AI is elucidated in enabling targeted applications of MXenes across multiple domains, illustrating the correlations between MXene properties and application performance. The synergistic integration of MXenes and AI marks the dawn of a new era in material design and innovation, with profound implications for advancing diverse technological frontiers.

Emerging 2D Nanomaterials-Integrated Hydrogels: Advancements in Designing Theragenerative Materials for Bone Regeneration and Disease Therapy

This review highlights recent advancements in the synthesis, processing, properties, and applications of 2D-material integrated hydrogels, with a focus on their performance in bone-related applications. Various synthesis methods and types of 2D nanomaterials, including graphene, graphene oxide, transition metal dichalcogenides, black phosphorus, and MXene are discussed, along with strategies for their incorporation into hydrogel matrices. These composite hydrogels exhibit tunable mechanical properties, high surface area, strong near-infrared (NIR) photon absorption and controlled release capabilities, making them suitable for a range of regeneration and therapeutic applications. In cancer therapy, 2D-material-based hydrogels show promise for photothermal and photodynamic therapies, and drug delivery (chemotherapy). The photothermal properties of these materials enable selective tumor ablation upon NIR irradiation, while their high drug-loading capacity facilitates targeted and controlled release of chemotherapeutic agents. Additionally, 2D-materials -infused hydrogels exhibit potent antibacterial activity, making them effective against multidrug-resistant infections and disruption of biofilm generated on implant surface. Moreover, their synergistic therapy approach combines multiple treatment modalities such as photothermal, chemo, and immunotherapy to enhance therapeutic outcomes. In bio-imaging, these materials serve as versatile contrast agents and imaging probes, enabling their real-time monitoring during tumor imaging. Furthermore, in bone regeneration, most 2D-materials incorporated hydrogels promote osteogenesis and tissue regeneration, offering potential solutions for bone defects repair. Overall, the integration of 2D materials into hydrogels presents a promising platform for developing multifunctional theragenerative biomaterials.

Multifunctional MXene-Based Platforms for Soft and Bone Tissue Regeneration and Engineering

MXenes and their composites hold great promise in the field of soft and bone tissue regeneration and engineering (TRE). However, there are challenges that need to be overcome, such as ensuring biocompatibility and controlling the morphologies of MXene-based scaffolds. The future prospects of MXenes in TRE include enhancing biocompatibility through surface modifications, developing multifunctional constructs, and conducting in vivo studies for clinical translation. The purpose of this perspective about MXenes and their composites in soft and bone TRE is to critically evaluate their potential applications and contributions in this field. This perspective aims to provide a comprehensive analysis of the challenges, advantages, limitations, and future prospects associated with the use of MXenes and their composites for soft and bone TRE. By examining the existing literature and research, the review seeks to consolidate the current knowledge and highlight the key findings and advancements in MXene-based TRE. It aims to contribute to the understanding of MXenes' role in promoting soft and bone TRE, addressing the challenges faced in terms of biocompatibility, morphology control, and tissue interactions.

MXenes for Bioinspired Soft Actuators: Advancements in Angle-Independent Structural Colors and Beyond

Soft actuators have garnered substantial attention in current years in view of their potential appliances in diverse domains like robotics, biomedical devices, and biomimetic systems. These actuators mimic the natural movements of living organisms, aiming to attain  enhanced flexibility, adaptability, and versatility. On the other hand, angle-independent structural color has been achieved through innovative design strategies and engineering approaches. By carefully controlling the size, shape, and arrangement of nanostructures, researchers have been able to create materials exhibiting consistent colors regardless of the viewing angle. One promising class of materials that holds great potential for bioinspired soft actuators is MXenes in view of their exceptional mechanical, electrical, and optical properties. The integration of MXenes for bioinspired soft actuators with angle-independent structural color offers exciting possibilities. Overcoming material compatibility issues, improving color reproducibility, scalability, durability, power supply efficiency, and cost-effectiveness will play vital roles in advancing these technologies. This perspective appraises the development of bioinspired MXene-centered soft actuators with angle-independent structural color in soft robotics.

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

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

Environmental implications of metal-organic frameworks and MXenes in biomedical applications: a perspective

Metal-organic frameworks (MOFs) and MXenes have demonstrated immense potential for biomedical applications, offering a plethora of advantages. MXenes, in particular, exhibit robust mechanical strength, hydrophilicity, large surface areas, significant light absorption potential, and tunable surface terminations, among other remarkable characteristics. Meanwhile, MOFs possess high porosity and large surface area, making them ideal for protecting active biomolecules and serving as carriers for drug delivery, hence their extensive study in the field of biomedicine. However, akin to other (nano)materials, concerns regarding their environmental implications persist. The number of studies investigating the toxicity and biocompatibility of MXenes and MOFs is growing, albeit further systematic research is needed to thoroughly understand their biosafety issues and biological effects prior to clinical trials. The synthesis of MXenes often involves the use of strong acids and high temperatures, which, if not properly managed, can have adverse effects on the environment. Efforts should be made to minimize the release of harmful byproducts and ensure proper waste management during the production process. In addition, it is crucial to assess the potential release of MXenes into the environment during their use in biomedical applications. For the biomedical applications of MOFs, several challenges exist. These include high fabrication costs, poor selectivity, low capacity, the quest for stable and water-resistant MOFs, as well as difficulties in recycling/regeneration and maintaining chemical/thermal/mechanical stability. Thus, careful consideration of the biosafety issues associated with their fabrication and utilization is vital. In addition to the synthesis and manufacturing processes, the ultimate utilization and fate of MOFs and MXenes in biomedical applications must be taken into account. While numerous reviews have been published regarding the biomedical applications of MOFs and MXenes, this perspective aims to shed light on the key environmental implications and biosafety issues, urging researchers to conduct further research in this field. Thus, the crucial aspects of the environmental implications and biosafety of MOFs and MXenes in biomedicine are thoroughly discussed, focusing on the main challenges and outlining future directions.