Protein repellent coatings have been extensively studied to introduce anti-fouling properties at material surfaces. Here we introduce a covalent anti-fouling coating at the surface of supramolecular ureidopyrimidinone (UPy) based materials introduced via post-modification of reactive UPy-functionalized tetrazine additives incorporated into the supramolecular polymer material. After material formulation, an antifouling coating comprised of bicyclononyne (BCN) functionalized poly(ethylene glycol) (PEG) polymers was reacted. This coating was covalently attached to the surface via a highly selective electron-demand Diels-Alder cycloaddition between tetrazine and BCN. The anti-fouling properties of three different BCN-PEG polymers, mono-functional-PEG-BCN, bi-functional-PEG-BCN and star-PEG-BCN, respectively, were systematically studied. The mono-functional-PEG-BCN showed minor reduction in both protein adsorption and cell adhesion, whereas the bi-functional-PEG-BCN and the star-PEG-BCN polymer coating demonstrated complete anti-fouling performance, both towards protein adhesion as well as cell adhesion. Additionally, a bioorthogonal ligation strategy was performed in culture medium in the presence of cells showing a similar behavior for the three anti-fouling coatings, which indicates that this strategy can be applied for post-modification reactions in a complex environment.

Much effort has been made in the development of biomaterials that synthetically mimic the dynamics of the natural extracellular matrix in tissues. Most of these biomaterials specifically interact with cells, but lack the ability to adapt and truly communicate with the cellular environment. Communication between biomaterials and cells is achieved by the development of various materials with enzyme-responsive moieties in order to respond to cellular cues. In this perspective, we discuss different enzyme-responsive systems, from surfaces to supramolecular assemblies. Additionally, we highlight their further prospects in order to create, inspired by nature, fully autonomous adaptive biomaterials that display dynamic reciprocal behavior. This Perspective shows new strategies for the development of biomaterials that may find broad utility in regenerative medicine applications, from scaffolds for tissue engineering to systems for controlled drug delivery.Perspective pubs.acs.org/Biomac