Title : MXene-based biomaterials in tissue engineering and functional implant coatings: Recent advances and future prospects
Abstract:
MXenes — two-dimensional transition-metal carbides and nitrides — have emerged as transformative materials in regenerative medicine. These materials, particularly Ti3C2Tx, offer a unique combination of metallic conductivity, hydrophilic surface chemistry, and robust mechanical properties. This presentation reviews recent breakthroughs in using MXenes to engineer advanced tissue scaffolds and smart biomaterial coatings. In tissue engineering, for example, MXene-infused hydrogels and 3D-bioprinted constructs dramatically enhance electroactive tissue regeneration. These materials accelerate neurite outgrowth on neural substrates and promote myogenic differentiation in cardiac patches. Furthermore, their rich surface termination groups (-O, -OH, -F, and -NH?) optimize cell anchoring and drive stem cell osteogenesis, even without exogenous growth factors. In bone implant applications, MXene-based coatings offer superior osseointegration and antibacterial activity against biofilm formation. They also provide near-infrared (NIR) and pH-responsive drug-delivery capabilities for localized therapy. Importantly, recent advances in fluoride-free green synthesis methods (e.g., alkali and electrochemical etching) have mitigated the risk of cytotoxicity, and biopolymer hybridization has overcome long-standing challenges in aqueous oxidation. In the first set of our experiments, Ti3C2Tx MXenes with different functional groups (-COOH and -NH?) were deposited on slightly heated tissue culture polystyrene (up to 60°C), improving adhesion to the substrate. The moderately hydrophilic MXenes functionalized with -COOH groups stimulated the proliferation of human adipose-derived mesenchymal stem cells. In contrast, the more hydrophobic MXenes functionalized with -NH? groups stimulated the osteogenic differentiation of these cells, as evidenced by expression of collagen I and alkaline phosphatase. This expression was measured at the mRNA level by real-time qPCR. In the second set of experiments, Ti3C2Tx MXenes were electrophoretically deposited onto Ti substrates, which are clinically used to construct bone implants. The -NH? functionalization was used to support osteogenic cell differentiation and to protect the MXene from oxidation and degradation. This functionalization was achieved by either a diazonium salt approach or an (aminopropyl)triethoxysilane (APTES)-based approach. During aging, oxidation of unprotected MXene flakes and formation of TiO? reduced the number of attached human bone marrow mesenchymal stem cells. However, prior protection of the flakes allowed the cells to grow and maintain metabolic activity on the aged flake surface. These results indicate that engineering the surface of MXenes is critical for controlling cell performance on these materials. Taken together, these promising results position MXenes at the forefront of next-generation, clinically viable biointerfaces.
Supported by the Czech Science Foundation (GA?R, grant No. 26-21031S), the Czech Acad. Sci. (Praemium Academiae grant No. AP2202), and P JAC Project “MeBioSys” No. CZ.02.01.01/00/22_008/0004634 of the MEYS, CR, co-funded by the European Union.
