Promoting Role of MXene Nanosheets in Biomedical Sciences : Therapeutic and Biosensing Innovations

MXene nanosheets have emerged as biocompatible transition metal structures, which illustrate desirable performance for various applications due to their unique structural, physicochemical, and compositional features. MXenes are currently expanding their usage territory from mechanical, optical, chemical, and electronic fields toward biomedical areas. This is mainly originated from their large surface area and strong absorbance in near-infrared region, which in combination with their facile surface functionalization with various polymers or nanoparticles, make them promising nanoplatforms for drug delivery, cancer therapy, precise biosensing and bioimaging. The facile surface modification of the MXenes can mediate the better in vivo performance of them through reduced toxicity, enhanced colloidal stability, and extended circulation within the body. Herein, the synthesis and state-of-the-art progresses of MXene nanosheets designed for biomedical applications, including structural- and dose-dependent antimicrobial activity, photothermal therapy, drug delivery, and implants are emphasized. Furthermore, biosensing applications are highlighted and a comprehensive discussion on photoacoustic imaging, magnetic resonance imaging, computed tomography imaging, and optical imaging of MXenes is presented. The challenges and future opportunities of applying MXene nanomaterials in the area of biomedicine are also discussed.Peer reviewe

Not-yet-designed multilayer Nb/HA/MWCNT-Au/Se/AuNPs and NbO2/HA/GO/Se biocomposites coated Ti6Al7Nb implant

Increased commercial demands of appropriate bone materials, smart multilayer biocomposites named niobium/hydroxyapatite/multiwall carbon nanotube hybrid gold/selenium/gold nanoparticles (Nb/HA/MWCNT-Au/Se/AuNPs) and niobium oxide/hydroxyapatite/graphene oxide/selenium (NbO2/HA/GO/Se) support Ti-6Al-7Nb implant alloy (Ti67IMP). Adhesion strength of primary as-deposited films was assessed by micro-scratch nanomaterial analysis. The microstructure, phase and elemental features of developed large-surface-area composites were characterized via FESEM, TEM/HRTEM, XPS, XRD/GIXRD, Raman and FT-IR techniques. Besides, in-vitro bioactivity study of reinforced Ti67IMP in simulated body fluid (SBF) media followed to evaluate the enhanced potential of bone-like apatite layer formation on treated surfaces comparatively. The designed multilayer biofilm-Ti67IMP systems may contribute to facilitate low-risk bone regeneration with antibacterial and drug delivery potential and long-term mechanical satisfaction

Large-scale hybrid silver nanowall-reduced graphene oxide biofilm: A novel morphology by facile electrochemical deposition

Increased attention has been focused on development of large-surface-area nanoengineered materials to enhance bone implants performance. Appropriate incorporations of functionalized carbon-based biofilms on the surface of artificial bone tissues can provide improved mechanobiological features. Besides, well-adhered potential coating interfaces corresponding wide spectrum antibacterial targets. Here, a novel morphology of hybrid silver (Ag) nanowall-green reduced graphene oxide (rGO) via facile methodology modified as-sputtered Ag grains to support Ti6Al7Nb implant (Ti67IMP) alloy. Layer-by-layer inorganic-organic topography obtained by physical vapor deposition magnetron sputtering (PVDMS) and subsequent one-step electrochemical deposition (ED) protocols. Microstructure, mechanical and wettability properties were characterized and cytocompatibility of designed composite-Ti67IMP system with human MG-63 osteosarcoma confirmed

Antibacterial biocompatible arginine functionalized mono-layer graphene: No more risk of silver toxicity

Antibacterial ability is vital in biological approaches as well as functional biomaterials. Besides, cytocompatibility aspect of biologic media, tissue and organs is always concern for appropriate synthesis. From the past, metallic/oxide phases of silver (Ag) material in various macro, micro or nano configurations have been widely used for antibacterial targets. While, background of Ag toxicity within particle, film and composites is posing gradual ion release affected by molecular bounding. Recent researches conducted to control, optimize and neutralize Ag limitations finding the benefits of ideal (∼ 100%) mediation against both Gram-negative and Gram-positive bacteria. Whereas, non-degradable releases history is still a challenge and its longer accumulation may cause to disrupt biostructures and disease risk. Thus, facile development of large-area organic materials with switchable bacteria toxicity and normal cell compatibility function is interesting for concerned approaches. Here, smart positively-charged stable arginine amino acid incorporated mono layer graphene (Arg-EMGr) nanobiocomposite introduced as useful antibacterial and safe bactericidal agent competitive with Ag direct. The immunity characteristic versus Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) comparably assessed with graphene oxide (GO) and different concentrations GO-AgNPs morphology. As cell viability matter, 1,3,5,7-days vitro culture assay shown attachment proliferation and cytotoxicity due to short interaction

Application of Ti 3 C 2 MXene Quantum Dots for Immunomodulation and Regenerative Medicine

Inflammation is tightly linked to tissue injury. In regenerative medicine, immune activation plays a key role in rejection of transplanted stem cells and reduces the efficacy of stem cell therapies. Next-generation smart biomaterials are reported to possess multiple biologic properties for tissue repair. Here, the first use of 0D titanium carbide (Ti3C2) MXene quantum dots (MQDs) for immunomodulation is presented with the goal of enhancing material-based tissue repair after injury. MQDs possess intrinsic immunomodulatory properties and selectively reduce activation of human CD4+IFN-γ+ T-lymphocytes (control 87.1 ± 2.0%, MQDs 68.3 ± 5.4%) while promoting expansion of immunosuppressive CD4+CD25+FoxP3+ regulatory T-cells (control 5.5 ± 0.7%, MQDs 8.5 ± 0.8%) in a stimulated lymphocyte population. Furthermore, MQDs are biocompatible with bone marrow-derived mesenchymal stem cells and induced pluripotent stem cell-derived fibroblasts. Finally, Ti3C2 MQDs are incorporated into a chitosan-based hydrogel to create a 3D platform with enhanced physicochemical properties for stem cell delivery and tissue repair. This composite hydrogel demonstrates increased conductivity while maintaining injectability and thermosensitivity. These findings suggest that this new class of biomaterials may help bridge the translational gap in material and stem cell-based therapies for tissue repair and treatment of inflammatory and degenerative diseases. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

Anodic pine cone-like WO3/MoO3/TiO2 film with well-defined nanoflakes on Ti–6Al–7Nb implant

A pine cone-shaped tungsten−molybdenum−titanium oxides combinatorial coating was successfully grown on Ti–6Al–7Nb implant (Ti67) by a combined approach of RF/DC physical vapor deposition (PVD) and one-pot anodization. The results indicated that the surface morphology and the phase composition were significantly changed as a function of sputtering target and anodization period. Prior to anodization, PVD coating process resulted in the formation of crystalline mono- and multi-layer Mo and Mo/W thin films. After anodization for 60 min, a crystalline mixed oxide structure was formed as a result of oncoming electrochemical reactions. Compared to a single bare substrate and as-sputtered Mo/W multi-layer coating, the 60-min-anodized specimen had the highest hydrophilicity as well as Vickers hardness and showed adhesion strength of around 397 ± 1 MPa. Remarkably, the proposed modification is not only limited to Mo/W multi-layer coating, but can also be employed to a wide range of other transition metals to form a mixed oxide mono-layer on the surface of medical-grade titanium alloys for potential biomedical applications

Simultaneous enhanced antibacterial and osteoblast cytocompatibility performance of Ti6Al7Nb implant by nano-silver/graphene oxide decorated mixed oxide nanotube composite

The self-ordered architecture allows for the exact design and control of geometrical features, to achieve materials with unique properties. For this reason, mixed oxide nanotube arrays have been highly regarded by the scientific community in recent years. In the present study, a hybrid approach of an optimized physical vapor deposition magnetron sputtering (PVDMS), electrochemical anodization as well as spin coating is proposed to improve the mechanical properties, corrosion resistance, antibacterial and osteoblast cytocompatibility performance of Ti6Al7Nb implant (Ti67IMP). Accordingly, controlled decorations of mixed oxide nanotube with silver nanoparticles/graphene oxide (AgNPs/GO) were designed to assess the biofunctionality of the modified Ti6Al7Nb implant. The results show that the surface modification has dramatically reduced the viability of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) cells. Besides, the AgNPs/GO loaded mixed oxide nanotube has significantly promoted cell adhesion and spreading, compared to the bare substrate. The proposed hybrid approach can also be extended to fabricate highly complex nanoarchitectures with controlled shape and biofunctionality for various orthopedic applications. © 2019 Elsevier B.V