“Bio-inspired soft materials through dynamic recognition motifs”
Nature abounds with examples of elegant structures and functions, often achieved by leveraging equilibrium-governed recognition motifs. These natural systems inspire the preparation of synthetic analogues with diverse function, to include uses as biomaterials and drug delivery devices. The nanoarchitecture of biological materials can arise from precisely engineering molecular-scale interactions, as well as through active perturbation of thermodynamic parameters to modulate the free energy landscape governing material formation. Such phenomena inspire the design of functional materials with precise nanoscale organization, as well as the use of stabilizing or destabilizing stimuli to realize responsive therapeutic function on demand. In this way, our lab has sought systems that adjust the state of associative interactions in response to biologically relevant triggers, such as glucose, in order to deliver therapeutics and address disease in real time with actively sensing material platforms. Nature similarly achieves remarkable function through high-affinity non-covalent recognition, with interactions such as biotin–avidin and antibody–antigen proving especially useful in facilitating recognition in a complex milieu. Host–guest supramolecular recognition offers a synthetic mimic of such affinity motifs. Tuning molecular-scale affinity affords an approach to control the bulk dynamics of a biomaterial, which translates to tunable release of encapsulated payloads, dictates the rate of cell infiltration, and controls the timescale of material clearance in vivo. Certain of these host–guest interactions are furthermore able to achieve affinities sufficient for recognition in complex or contaminated environments, and offer a new non-biological axis for drug homing and retention at desired sites in the body. As such, the ability to leverage non-covalent interactions from synthetic motifs enables aspects of natural biological materials and systems to be replicated, with specific functional utility in the delivery of therapeutics and creation of new biomaterials.