Abstract

Heparin and heparan sulfate (HS) glycosaminoglycans (GAGs), essential components of the extracellular matrix (ECM), regulate a vast array of biological processes by modulating protein interactions and cellular signaling. Their structural complexity, driven by diverse sulfation patterns, underpins their broad physiological activities, including cell proliferation, differentiation, and neural development. However, the intrinsic heterogeneity of native HS complicates the elucidation of structure-activity relationships (SAR), hindering efforts to fully harness their therapeutic potential. This challenge underscores the need for structurally defined HS glycomimetics that can replicate the functional diversity of native HS with precise control and optimized therapeutic effects. 2 Here, we present a library of HS glycomimetics, rationally designed using molecular modeling and synthesized through a divergent synthesis strategy that allows sulfate groups to be installed at specific positions along the carbohydrate backbone. Biophysical characterizations unveil that these glycomimetics selectively bind and stabilize growth factors, including fibroblast growth factors (FGF-1, FGF-2) and nerve growth factor (NGF), in a sulfation-dependent manner without inducing anticoagulant activity, which is a critical prerequisite for successful clinical translation in nerve regeneration. The lead glycomimetic has neuritogenic ability because in two neuronal cell models, PC12 and SH-SY5Y, it enhances NGF-mediated neural maturation when immobilized on a surface. Moreover, functional studies in primary rat hippocampal neurons reveal that the lead glycomimetic potentiates FGF-2- mediated neurite outgrowth and spontaneous synaptic activity, effectively translating its molecular interactions into measurable cellular responses. By bridging molecular-level insights with functional bioactivity, this work establishes HS glycomimetics as precision tools for neurotrophic signaling. Their ability to fine-tune growth factor activity offers a versatile platform for regenerative medicine, extending beyond neural regeneration to broader tissue repair applications. These findings advance the development of next-generation carbohydrate-based therapeutics, unlocking new opportunities for precise and targeted regenerative strategies.

Publications

Riva, E. R., Özkan, M., Contreras, E., Pawar, S., Zinno, C., Escarda-Castro, E., ... & Navarro, X. (2024). Beyond the limiting gap length: peripheral nerve regeneration through implantable nerve guidance conduits. Biomaterials science, 12(6), 1371-1404.

Redolfi Riva, E., Özkan, M., Stellacci, F., & Micera, S. (2024). Combining external physical stimuli and nanostructured materials for upregulating pro-regenerative cellular pathways in peripheral nerve repair. Frontiers in Cell and Developmental Biology, 12, 1491260.