Biology subjects

Asadi Tokmedash, M.

Publications and source records attributed to Asadi Tokmedash, M..

2 recordsLinked to original sources

bioRxiv2026

Dynamically actuated reconfigurable topographical surface enables active control of implant-associated infections

Implant-associated infections are driven by bacterial biofilm formation and remain difficult to eradicate using conventional antibiotic-based strategies. Here, we present a dynamically actuated reconfigurable topographical surface (DARTS) that integrates intrinsically bactericidal nanoscale surface topography with programmable mechanical actuation to achieve durable, antibiotic-free infection control. Using a scalable bottom-up nanofabrication strategy, we generate tunable wrinkled MXene topographies that exhibit contact-mediated bactericidal activity against both Gram-positive and Gram-negative bacteria without chemical leaching. Integration with a soft robotic actuator enables reversible modulation of surface geometry, which synergistically enhances bacterial removal and killing, resulting in near-complete disruption of mature biofilms. Dynamic actuation further sensitizes released bacteria to antibiotic treatment. In a mouse subcutaneous implant infection model, DARTS with actuation achieves sustained suppression of bacterial burden and markedly improves host tissue outcomes. Remote, noninvasive actuation using near-infrared laser stimulation further highlights the translational potential of this platform for implantable antibacterial applications. Significance StatementImplant infections are difficult to treat because bacteria form biofilms that protect them from antibiotics and the immune system. Current materials often rely on chemical release, which can lose effectiveness over time. Here, we present a new surface that both kills bacteria and removes them. The surface uses nanoscale features to physically damage bacterial cells, while dynamic motion clears attached bacteria and biofilms. This allows continuous, chemical-free control of infection. In a mouse implant model, the system greatly reduced bacterial burden and improved tissue healing. This work introduces a new way to control bacteria using dynamic surface design and could be applied not only to medical implants but also to environmental, food, textile, and marine systems.

bioengineering↗

bioRxiv2024

Designer micro/nano-crumpled MXene multilayer coatings accelerate osteogenesis and regulate macrophage polarization

Effective tissue regeneration and immune responses are essential for the success of biomaterial implantation. Although the interaction between synthetic materials and biological systems is well-recognized, the role of surface topographical cues in regulating the local osteoimmune microenvironment--specifically, their impact on host tissue and immune cells and their dynamic interactions--remains underexplored. This study addresses this gap by investigating the impact of surface topography on osteogenesis and immunomodulation. We fabricated MXene/Hydroxyapatite (HAP)-coated surfaces with controlled 2.5D nano-, submicro-, and micro-scale topographical patterns using our custom bottom-up pattering method. These engineered surfaces were employed to assess the behavior of osteoblast precursor cells and macrophage polarization. Our results demonstrate that MXene/HAP-coated surfaces with microscale crumpled topography significantly influence osteogenic activity and macrophage polarization: These surfaces notably enhanced osteoblast precursor cell spreading, proliferation, differentiation, and facilitated a shift in macrophages towards an anti-inflammatory, pro-healing M2 phenotype. The observed cell responses indicate that the physical cues from the crumpled topographies, combined with the chemical cues from the MXene/HAP coatings, synergistically create a favorable osteoimmune microenvironment. This study presents the first evidence of employing MXene/HAP-multilayer coated surfaces with finely crumpled topography to concurrently facilitate osteogenesis and immunomodulation for improved implant-to-tissue integration. The tunable topographic patterns of these coatings, coupled with a facile and scalable fabrication process, make them widely applicable for various biomedical purposes. Our results highlight the potential of these novel coatings to improve the in vivo performance and fate of implants by modulating the host response at the material interface.

bioengineering↗