Dynamic Combinatorial Optimization of In Vitro and In Vivo Heparin Antidotes

Heparin-like macromolecules are widely used in clinics as anticoagulant, antiviral, and anticancer drugs. However, the search of heparin antidotes based on smallsynthetic molecules to control blood coagulation still remains a challenging task due to the physicochemical properties of this anionic polysaccharide. Here, we use a dynamiccombinatorial chemistry approach to optimize heparin binders with submicromolaraffinity. The recognition of heparin by the most amplified members of the dynamic library has been studied with different experimental (SPR,fluorescence, NMR) andtheoretical approaches, rendering a detailed interaction model. The enzymatic assayswith selected library members confirm the correlation between the dynamic covalentscreening and thein vitroheparin inhibition. Moreover, bothex vivoandin vivobloodcoagulation assays with mice show that the optimized molecules are potent antidotes with potential use as heparin reversal drugs.Overall, these results underscore the power of dynamic combinatorial chemistry targeting complex and elusive biopolymers