Latest advances on MXenes in biomedical research and health care

Abstract

The unique combination of physical and chemical properties of MXenes has propelled a growing number of applications in biomedicine and healthcare. The expanding library of MXenes with tunable properties is paving the way for high-performance, application-specific MXene-based sensing and therapeutic platforms. In this article, we highlight the emerging biomedical applications of MXenes with specific emphasis on bioelectronics, biosensors, tissue engineering, and therapeutics. We present examples of MXenes and their composites enabling novel technological platforms and therapeutic strategies, and elucidate potential avenues for further developments. Finally, we discuss the materials, manufacturing, and regulatory challenges that need to be synergistically addressed for the clinical translation of MXene-based biomedical technologies.

Keywords: Bioelectronics; Biosensing; Clinical translation; MXene; Therapeutics; Tissue engineering.

Figure 1

Biomedical applications of MXenes. Shaded ovals highlight emerging applications and areas of research from 2019 to date. PTT, photothermal therapy; PDT, photodynamic therapy.

Figure 2

Bioelectronics and multimodal biosensing with MXenes. (a) Schematics of an intracortical array patterned with 25 µm Ti₃C₂T_x and adjacent Au contacts for recording neural activity in vivo. The close-up view shows a scanning electron microscopy image of the surface of one Ti₃C₂T_x contact. The arrays can record in vivo intracortical neural activity with higher signal-to-noise ratio and reduced susceptibility to 60 Hz interference than Au (reproduced with permission from Reference 21). (b) Photograph of Ti₃C₂T_x-infused electrode arrays for electroencephalography (EEG). (c) MXene EEG electrode array placed on human forehead and imaged in 3T clinical MRI scanner using T1-weighted magnetization prepared rapid acquisition gradient echo. (b, c) Reproduced with permission from Reference . (d) Schematics of the photothermal stimulation of a dorsal root ganglion (DRG) neuron network with Ti₃C₂T_x flakes (reproduced with permission from Reference 30). (e) Schematics illustrating the operation of ssDNA/Ti₃C₂T_x sensors for the detection of SARS-CoV-2 nucleocapsid (N) gene (reproduced with permission from Reference 39). (f) Schematic illustrating DNA translocation through a MXene nanopore sensor (reproduced with permission from Reference 44). (g) Photoluminescent Ti₃C₂T_x MXene quantum dots (MQDs) for multicolor cellular imaging. UV–vis spectra (solid line), photoluminescence excitation (PLE) (dashed line), and photoluminescence (PL) spectra (solid line, Ex = 320 nm) of MQD-100 in aqueous solutions. (h) Merged bright-field and confocal images (Ex = 488 nm) of MQD-100 interfaced with RAW 264.7 cells. (g, h) Reproduced with permission from Reference .

Figure 3

Tissue engineering and therapeutic technologies enabled by MXenes. (a) Representative newly generated neurons cultured on Ti₃C₂T_x flakes. (b) Average length of neurites for new neurons cultured on tissue culture polystyrene (TCPS) and Ti₃C₂T_x. ** p < 0.01. (a, b) Adapted with permission from Reference . (c) Printed Ti₃C₂T_x on PEG hydrogel with a square (81 mm²) pattern. The inset presents patterned-induced pluripotent stem cell derived cardiomyocytes on 3D printed Ti₃C₂T_x-PEG hydrogel after seven days in culture (reproduced with permission from Reference 56). (d) Schematic illustrating 3D Ti₃C₂T_x MXene–Matrigel with electroacoustic stimulation for enhanced growth of spiral ganglion neurons (reproduced with permission from Reference 57). (e) Schematic representation of in vitro immunomodulatory model (reproduced with permission from Reference 61). (f) Schematics of Ti₃C₂T_x flakes as adsorbents for urea in dialysate. (g) Urea removal efficiency (%) from dialysate using different mass loadings of Ti₃C₂T_x. (f, g) Reproduced with permission from Reference . (h) Schematics of a proof-of-concept design for Ti₃C₂T_x adjustable focus lens. (i) (Top) Schematic of Ti₃C₂T_x spin-cast onto an acrylate intraocular lens (IOL); (bottom) optical power measurement on three different lens powers before and after coating with Ti₃C₂T_x (n = 5). Inset is an optical image of spin-coated IOL. (h, i) Reproduced with permission from Reference .