Sulfated Poly-Amido-Saccharide (sulPAS) Biomaterials as Anticoagulants

PROJECT SUMMARY/ABSTRACT This proposal describes a novel biomaterial and synthetic anticoagulant. Anticoagulants are a mainstay of modern surgery and of clotting disorder management such as venous thrombosis, yet performance and supply limitations exist for the most widely used agent - heparin. Specifically, heparin’s heterogeneous structure affords highly variable activity, patient-dependent dose-responses, and life-threatening side effects such as heparin induced thrombocytopenia. Additionally, African Swine Fever (a double-stranded DNA virus in the Asfarviridae family) has wiped out over one-quarter of the world’s pig population leading to global shortages, contamination issues, and the need for alternatives – i.e., anticoagulants of non-animal origin. We propose the use of disulfated poly-amido-saccharides (PASs) as heparin mimetics. PASs are new well- defined, enantiopure carbohydrate polymers that are stereochemically defined, hydrophilic, and possess pyranose rings in the backbone. PASs are efficiently synthesized by the anionic ring-opening polymerization reaction of a β-lactam sugar monomer in high-yields with batch-to-batch consistency, defined molecular weights, and low polydispersity. Sulfation of PAS yields such unique heparin mimetics. Herein, we describe the novel synthesis along with detailed in vitro and ex vivo mechanism-of-action and in vivo efficacy studies. The proposed experiments will define the molecular and structural basis for anticoagulant activity of disulfated PAS (disulPAS) and will test the hypothesis that regioselectively functionalized disulPASs will be: 1) efficacious in vivo with activity equivalent to or better than low molecular weight heparin (LMWH); and 2) neutralized by protamine sulfate unlike synthetic Fondaparinux. Further, sulPAS anticoagulant activity will depend on the number and the position of sulfate functionalization and not be associated with heparin-induced thrombocytopenia. Importantly, substantial preliminary data support the proposed studies, well-characterized materials and rigorous experimental designs are established, and essential cross-disciplinary collaborations and expertise are in place to address the hypotheses. The specific aims of this five-year proposal are as follows. Aim 1 synthesizes and characterizes new regioselectively disulfated PAS. Aim 2 evaluates the in vitro/ex vivo anticoagulant activity and determines the mechanism of action (MOA) of disulfated PASs. Aim 3 defines the pharmacokinetic and pharmacodynamic profile of lead disulPAS candidates and efficacy in rodent models of thromboprophylaxis and bleeding risk.