Search for: All records

Abstract Implant‐associated complications—including infection, adverse immune responses, and poor tissue integration—pose significant risks to patients, often leading to implant failure, revision surgeries, or chronic disease. Current chemical‐based strategies, such as antibiotic or drug‐releasing systems, are limited by short‐term efficacy, narrow therapeutic windows, and potential toxicity. Surface topography offers a promising alternative, but most designs target single cell types and overlook the complex, multicellular dynamics at the implant–host interface. Here, a new multifunctional platform is introduced based on nano–micro hybrid wrinkled topographies fabricated via a custom nanofabrication method that combines layer‐by‐layer (LbL) self‐assembly with mechanical nanomanufacturing. This system simultaneously modulates bacteria, immune cells, and tissue progenitors to enable antibacterial activity, immune regulation, and tissue regeneration. On hybrid surfaces, nanoscale features disrupt bacterial adhesion (>50% biofilm reduction vs. flat controls), while microscale features enhance macrophage polarization (≈3‐fold increase in M2 markers) and osteogenic differentiation (>8‐fold increase in ALP activity), indicating strong pro‐healing responses. Notably, macrophages exhibit context‐dependent behavior—driving inflammation during bacterial infection and repair in its absence—creating an immune‐balanced microenvironment for implant integration. The modular nature of this platform allows expansion to other cell types and disease contexts, offering a broadly applicable strategy for next‐generation biomaterials. 

ABSTRACT Infection of wounds delays healing, increases treatment costs, and leads to major complications. Current methods to manage such infections include antibiotic ointments and antimicrobial wound dressings, both of which have significant drawbacks, including frequent reapplication and contribution to antimicrobial resistance. In this work, we developed wound dressings fabricated with a medical-grade polyurethane coating composed of natural plant secondary metabolites, cinnamaldehyde, and alpha-terpineol. Our wound dressings are easy to change and do not adhere to the wound bed. They kill gram-positive and -negative microbes in infected wounds due to the Food and Drug Administration–approved for human consumption components. The wound dressings were fabricated by dip coating. Antimicrobial efficacy was determined by quantifying the bacteria colonies after a 24 h of immersion. Wound healing and bacterial reduction were assessed in anin vivofull-thickness porcine burn model. Our antimicrobial wound dressings showed a > 5-log reduction (99.999%) of different gram-positive and gram-negative bacteria, while maintaining absorbency. In thein vivoporcine burn model, our wound dressings were superior to bacitracin in decreasing bacterial burden during daily changes, without interfering with wound healing. Additionally, the dressings had a significantly lower adhesion to the wound bed. Our antimicrobial wound dressings reduced the burden of clinically relevant bacteria more than commercial antimicrobial wound dressings. In anin vivoinfected burn wound model, our coatings performed as well or better than bacitracin. We anticipate that our wound dressings would be useful for the treatment of various types of acute and chronic wounds. 

Fungi such as Candida albicans exist in biofilm phenotypes, which present as viscoelastic materials; however, a method to measure linear viscoelastic moduli, yield stress, and yield strain is lacking. Characterization methods for fungal materials have been limited to techniques specific to particular industries. Here, we present a method to measure the shear stress, strain amplitude, and creep of C. albicans BWP17 biofilms. Our method includes features tailored to the analysis of fungi including an in vitro growth protocol attuned to the slow growth rates of C. albicans biofilms and a resultant cultured biofilm that has sufficient integrity to be transferred to the rheometer tooling without disrupting its structure. The method's performance is demonstrated by showing that results are insensitive to gap, evaporative sealant, length of experiment, and specimen radius. Multiscale imaging of the fungal biofilm showed complex entanglement networks at the hundred-micrometer scale. For a wild-type strain cultivated for 14 days, using small-amplitude oscillatory rheology, we found that the elastic (G′) and viscous (G″) moduli were nearly independent of frequency over the range 0.1–10 s −1 , with magnitudes of [Formula: see text] and [Formula: see text], respectively. The yield stress was approximately [Formula: see text]. We modeled the linear creep response of the fungal biofilm and found that C. albicans has a characteristic relaxation time of [Formula: see text] and a viscosity of [Formula: see text]. We applied this method to probe the effects of altered chitin deposition in the C. albicans cell wall. Differences between the biofilm's phenotypic cell shape and rheological properties in mutants with altered chitin synthase activity were resolved. Discovering how genotypic, phenotypic, and environmental factors impact the material properties of these microbial communities can have implications for understanding fungal biofilm growth and aid in the development of remediation strategies.