# Supramolecular helicity dependent osteogenesis and angiogenesis crosstalk of periodontal ligament stem cell

## TL;DR

This study shows how chiral fibrils can guide stem cells to regenerate bone and blood vessels together, using a new biomaterial design strategy.

## Contribution

A chirality-driven biomaterial system is developed to synergistically enhance osteogenesis and angiogenesis via supramolecular helicity.

## Key findings

- Left-handed fibrils promote osteogenic differentiation and pro-angiogenic secretion in PDLSCs.
- Chiral topology activates integrin α5β1 and dual signaling pathways for bone and blood vessel formation.
- The system effectively regenerates bone in calvarial and alveolar defect models.

## Abstract

The two pillars supporting effective tissue regeneration are multipotent stem cells and matrix materials that direct differentiation. The chirality of the extracellular matrix is a key structural characteristic that affects stem cell fate. However, little is known about the effects of either molecular chirality or supramolecular helicity on the differentiation of periodontal ligament stem cells (PDLSCs), a safe and easily accessible stem cell source. Here, we constructed fibrils through the co-assembly of chiral amino acid derivative enantiomers (l/d-GC18) and a bridging pyrazine molecule. The helicity of the fibrils depends on both the molecular chirality of the amino acid and the stoichiometric ratio of the two components. Our results showed that molecular chirality and supramolecular helicity can act synergistically, with the left-handed fibrils assembled from l-GC18 and pyrazine promoting osteogenic differentiation of PDLSCs in vivo. Moreover, the chiral fibrils effectively promoted bone regeneration in both the calvarial and alveolar bone defect models. Interestingly, it was observed that left-handed fibrils induced integrin-dependent osteogenic differentiation, which in turn stimulated Piezo1-mediated, Vascular Endothelial Growth Factor (VEGF)-driven angiogenesis. These findings thus provide a blueprint for harnessing PDLSCs in next-generation regenerative therapeutics.

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•We developed a bioinspired chiral amino acid-derived system that self-assembles into supramolecular fibrils with programmable helicity, characterized using AFM and Cryo-EM.•Left-handed helicity selectively enhances osteogenic differentiation and pro-angiogenic paracrine secretion in periodontal ligament stem cells (PDLSCs), thereby coupling osteogenesis with angiogenesis.•Mechanistically, chiral topology activates integrin α5β1-mediated mechanotransduction, triggering dual signaling pathways: (1) FAK-ERK-YAP/RUNX2 for osteogenesis and (2) Piezo1-Ca²⁺-HIF1α-VEGF for angiogenesis.•The left-handed fibril/PDLSC construct promotes robust bone regeneration in critical-sized calvarial and alveolar defect models.•This work establishes a chirality-driven biomaterial design strategy that leverages mechano-chemical crosstalk to program stem cell microenvironments for synergistic tissue regeneration.

We developed a bioinspired chiral amino acid-derived system that self-assembles into supramolecular fibrils with programmable helicity, characterized using AFM and Cryo-EM.

Left-handed helicity selectively enhances osteogenic differentiation and pro-angiogenic paracrine secretion in periodontal ligament stem cells (PDLSCs), thereby coupling osteogenesis with angiogenesis.

Mechanistically, chiral topology activates integrin α5β1-mediated mechanotransduction, triggering dual signaling pathways: (1) FAK-ERK-YAP/RUNX2 for osteogenesis and (2) Piezo1-Ca²⁺-HIF1α-VEGF for angiogenesis.

The left-handed fibril/PDLSC construct promotes robust bone regeneration in critical-sized calvarial and alveolar defect models.

This work establishes a chirality-driven biomaterial design strategy that leverages mechano-chemical crosstalk to program stem cell microenvironments for synergistic tissue regeneration.