Hydrogels that mimic developmentally relevant matrix and N-cadherin interactions enhance MSC chondrogenesis

TLDR

Methacrylated hyaluronic acid hydrogels provide a scaffold that engages MSCs via CD44/CD168 and, together with N‑cadherin‑mediated cell–cell interactions, support chondrogenesis during embryonic development. The study aims to functionalize HA hydrogels with N‑cadherin mimetic peptides to assess their influence on MSC chondrogenesis and cartilage matrix deposition. HA hydrogels were conjugated with N‑cadherin peptides and MSCs were encapsulated, then chondrogenic differentiation and matrix production were evaluated in vitro and in vivo. Peptide‑functionalized hydrogels accelerated early MSC chondrogenesis and cartilage matrix synthesis, an effect abolished by N‑cadherin antibodies, and produced superior neocartilage in subcutaneous implants, demonstrating the bioactivity of HA hydrogels and the potential of mimicking embryonic microenvironments for cartilage regeneration.

Abstract

Methacrylated hyaluronic acid (HA) hydrogels provide a backbone polymer with which mesenchymal stem cells (MSCs) can interact through several cell surface receptors that are expressed by MSCs, including CD44 and CD168. Previous studies showed that this 3D hydrogel environment supports the chondrogenesis of MSCs, and here we demonstrate through functional blockade that these specific cell–material interactions play a role in this process. Beyond matrix interactions, cadherin molecules, a family of transmembrane glycoproteins, play a critical role in tissue development during embryogenesis, and N-cadherin is a key factor in mediating cell–cell interactions during mesenchymal condensation and chondrogenesis. In this study, we functionalized HA hydrogels with N-cadherin mimetic peptides and evaluated their role in regulating chondrogenesis and cartilage matrix deposition by encapsulated MSCs. Our results show that conjugation of cadherin peptides onto HA hydrogels promotes both early chondrogenesis of MSCs and cartilage-specific matrix production with culture, compared with unmodified controls or those with inclusion of a scrambled peptide domain. This enhanced chondrogenesis was abolished via treatment with N-cadherin–specific antibodies, confirming the contribution of these N-cadherin peptides to chondrogenesis. Subcutaneous implantation of MSC-seeded constructs also showed superior neocartilage formation in implants functionalized with N-cadherin mimetic peptides compared with controls. This study demonstrates the inherent biologic activity of HA-based hydrogels, as well as the promise of biofunctionalizing HA hydrogels to emulate the complexity of the natural cell microenvironment during embryogenesis, particularly in stem cell-based cartilage regeneration.