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Many postsurgical complications stem from bacteria colony formation on the surface of implants, but the usage of antibiotic agents may cause antimicrobial resistance. Therefore, there is a strong demand for biocompatible materials with an intrinsic antibacterial resistance not requiring extraneous chemical agents. In this study, homogeneous nanocones were fabricated by oxygen plasma etching on the surface of natural, biocompatible Bombyx mori silk films. The new hydroxyl bonds formed on the surface of the nanopatterned film by plasma etching increased the surface energy by around 176%. This hydrophilic nanostructure reduced the bacterial attachment by more than 90% for both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria and at the same time improved the proliferation of osteoblast cells by 30%. The nanoengineered substrate and pristine silk were cultured for 6 h with three different bacteria concentrations of 107, 105, and 103 CFU mL–1 and the cell proliferation on the nanopatterned samples was significantly higher due to limited bacteria attachment and prevention of biofilm formation. The concept and materials described here reveal a promising alternative to produce biomaterials with an inherent biocompatibility and bacterial resistance simultaneously to mitigate postsurgical infections and minimize the use of antibiotics.

to abuse of antibiotics and secondary pollution. [2] In fact, most antibacterial materials may not have the proper mechanical, chemical, physical, and even biological properties required by practical applications. Moreover, addition of real-time bacteria monitoring to the antibacterial platform is highly desirable for biomedical engineering, aquaculture, agriculture, and environmental engineering as the complete process can be monitored. [3] Hence, biomaterials that can both sense and kill bacteria without deleterious effects are imperative to better healthcare and environmental research. However, little effort has so far been devoted to integrating sensors into one smart antibacterial platform which will otherwise shorten the detection-to-action time to fend off uncontrollable bacteria proliferation. In the case of bacteria detection, there are currently two types of techniques: ones requiring sample processing and systems targeting unprocessed samples but requiring complicated reactions. [4] The former techniques include counting of colony-forming units or the polymerase chain reaction (PCR) while the latter include biosensors based on antibodies, aptamers, and fluorescence. [5] Colony counting or PCR is time-consuming and laborious, whereas the currently available biosensors rely on biochemical interactions, require immobilization of the bio-reporter,

In bone implants, antibacterial biomaterials with nonleaching surfaces are superior to ones based on abrupt release because systemic side effects arising from the latter can be avoided. In this work, a nonleaching antibacterial concept is demonstrated by fabricating 2D nanoflakes in situ on magnesium (Mg). Different from the conventional antibacterial mechanisms that depend on Mg2+ release and pH increase, the nanoflakes exert mechanical tension onto the bacteria membranes to destroy microorganisms on contact and produce intracellular stress via physical interactions, which is also revealed by computational simulations. Moreover, the nanoflake layer decelerates the corrosion process resulting in mitigated Mg2+ release, weaker alkalinity in the vicinity, and less hydrogen evolution, in turn inducing less inflammatory reactions and ensuring the biocompatibility as confirmed by the in vivo study. In this way, bacteria are killed by a mechanical process causing very little side effects. This work provides information and insights pertaining to the design of multifunctional biomaterials.