Stem Cells From the Apical Papilla Cultured in Spheroids Spontaneously Differentiate Into Odontoblasts via N‐Cadherin Downregulation

Traditional monolayer cultures of stem cells from the apical papilla (SCAP) fall short in their ability to replicate the anatomical organization of SCAP and often fail to provide high-quality SCAP suitable for dental root regeneration. This study aimed to employ agarose-based low-adhesion plates to induce the spontaneous formation of SCAP spheroids and disclose the biological impacts of SCAP in forming papilla-like structures in vivo. Compared with monolayer-cultured SCAP, spheroid-cultured SCAP exhibited enhanced in vitro and in vivo odontoblastic differentiation potentials. RNA sequencing identified the importance of N-cadherin downregulation in enhancing the odontoblastic differentiation potential of SCAP in spheroids compared with monolayer-cultured SCAP. Furthermore, N-cadherin knockdown in vitro significantly upregulated the β-catenin signaling pathway, further promoting SCAP odontoblastic differentiation. SCAP cultured on agarose-based plates spontaneously form spheroids and undergo odontoblastic differentiation through N-cadherin downregulation, offering new insights into SCAP-mediated dentin regeneration.