In living systems, fuel-driven assembly is ubiquitous, and examples include the formation of microtubules or actin bundles. These structures have inspired researchers to develop synthetic counterparts, leading to exciting new behaviors in man-made structures. However, most of these examples are serendipitous discoveries because clear design rules do not yet exist. In this work, we show design rules to drive peptide self-assembly regulated by a fuel-driven reaction cycle. We demonstrate that, by altering the ratio of attractive to repulsive interactions between peptides, the behavior can be toggled between no assembly, fuel-driven dissipative self-assembly, and a state in which the system is permanently assembled. These rules can be generalized for other peptide sequences. In addition, our finding is explained in the context of the energy landscapes of self-assembly. We anticipate that our design rules can further aid the field and help the development of autonomous materials with life-like properties.

The immune‐mediated foreign body response to biomaterial implants can trigger the formation of insulating fibrotic capsules that can compromise implant function. To address this challenge, the intrinsic bioactivity of the mucin biopolymer, a heavily glycosylated protein that forms the protective mucus gel covering mucosal epithelia, is leveraged. By using a bioorthogonal inverse electron demand Diels–Alder reaction, mucins are crosslinked into implantable hydrogels. It is shown that mucin hydrogels (Muc‐gels) modulate the immune response driving biomaterial‐induced fibrosis. Muc‐gels do not elicit fibrosis 21 days after implantation in the peritoneal cavity of C57Bl/6 mice, whereas medical‐grade alginate hydrogels are covered by fibrous tissues. Further, Muc‐gels dampen the recruitment of innate and adaptive immune cells to the gel and trigger a pattern of very mild activation marked by a noticeably low expression of the fibrosis‐stimulating transforming growth factor beta 1 cytokine. Macrophages recruited to Muc‐gels upregulate the gene expression of the protein inhibitor of activated STAT 1 (PIAS1) and SH2‐containing phosphatase 1 (SHP‐1) cytokine regulatory proteins, which likely contributes to their low cytokine expression profiles. With this advance in mucin materials, an essential tool is provided to better understand mucin bioactivities and to initiate the development of new mucin‐based and mucin‐inspired “immune‐informed” materials for implantable devices subject to fibrotic encapsulation.

It was a physicist, Wolfgang Pauli, who recognized a century ago that “God made the bulk; the surface was invented by the devil.” And indeed, adjusting the surface properties of materials has kept engineers and chemists busy since—and it still does. In the context of biomedical engineering, the key challenge is ensuring the functionality of an artificial object, which is inserted into the human body—an environment that passively and actively rejects foreign materials. Here, recent advances in this area while focusing on those approaches that employ surface coating strategies with biopolymers are summarized.

Approximately 10% of all hospital patients contract infections from temporary clinical implants such as urinal and vascular catheters or tracheal tubes. The ensuing complications reach from patient inconvenience and tissue inflammation to severe, life threatening complications such as pneumonia or bacteremia. All these device‐associated nosocomial infections have the same origin: biofouling, i.e., the unwanted deposition of proteins, bacteria, and cells onto the device. To date, most strategies to overcome these problems are device specific, which results in high development efforts and costs. Here, it is demonstrated how one and the same coupling mechanism can be used to create a covalent antifouling coating employing mucin glycoproteins on multiple materials: with this method, a stable mucin layer can be generated on a broad range of polymer materials which are frequently used in medical engineering. It is shown that the mucin coating exhibits excellent stability against mechanical, thermal, and chemical challenges and reduces protein adsorption as well as prokaryotic and eukaryotic cell adhesion. Thus, the coating mechanism described here introduces a promising strategy to overcome biofouling issues on a broad range of medical devices.

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