Stretchable, Nano-Crumpled MXene Multilayers Impart Long-Term Antibacterial Surface Properties

Abstract

Infections are a significant risk to patients who receive medical implants, and can often lead to implant failure, tissue necrosis, and even amputation. So far, although various surface modification approaches are proposed for prevention and treatment of microbial biofilms on indwelling medical devices, most are too expensive/complicated to fabricate, unscalable, or limited in durability for clinical use. Here, this work presents a new bottom-up design for fabricating scalable and durable nano-patterned coatings with dynamic topography for long-term antibacterial effects. This work shows that MXene layer-by-layer (LbL) self-assembled coatings—with finely tunable crumpled structures with nanometer resolution and excellent mechanical durability—can be successfully fabricated on stretchable poly(dimethylsiloxane) (PDMS). The crumpled MXene coating with sharp-edged peaks shows potent antibacterial effects against Staphylococcus aureus and Escherichia coli. In addition, this work finds that on-demand dynamic deformation of the crumpled coating can remove ≥99% of adhered bacterial cells for both species, resulting in a clean surface with restored functionality. This approach offers improved practicality, scalability, and antibacterial durability over previous methods, and its flexibility may lend itself to many types of biomaterials and implantable devices.After implantation, opportunistic bacteria can readily attach to biomaterial surfaces and cause infection. Unlike a planar surface where the attached bacteria can form biofilm, the nano-crumpled MXene multilayers on stretchable surfaces can induce bacteria killing, and the subsequent application of mechanical stretching can induce dynamic surface deformation to release the dead cells, resulting in a clean surface with restored multifunctionality.