Synthetic receptors for steroids: from molecular recognition to biomedical functions

Aqueous-phase molecular recognition plays a central role in many biological systems, motivating the development of artificial receptors capable of operating in water. Steroidal compounds, defined by a rigid tetracyclic framework and encompassing biologically important molecules such as cholesterol, steroid hormones, and therapeutic agents, constitute a representative and challenging class of targets for supramolecular recognition. Historical milestones, including Cramer's 1954 observation that cyclodextrins can bind cholesterol and steroid hormones via hydrophobic encapsulation, and the clinical development of sugammadex, a γ-cyclodextrin derivative that antagonizes neuromuscular blocking agents, illustrate both the scientific and translational significance of steroid recognition. This review focuses on the supramolecular recognition of steroids, highlighting representative synthetic receptors and their binding properties. We further survey applications in sensing, solubilization, antagonism, and therapeutic intervention, emphasizing how artificial receptors enable the modulation of steroid-related processes. By providing a coherent overview of representative systems, functional performance, and biomedical applications, this study aims to stimulate further research on supramolecular recognition of bioactive compounds and to foster closer integration between supramolecular chemistry and biomedical and pharmaceutical sciences.