Effects of a Bioactive Scaffold Containing a Sustained Transforming Growth Factor-β1 releasing Nanoparticle System on the Migration and Differentiation of Stem Cells from the Apical Papilla

Introduction: This 2-part study hypothesized that a bioactive scaffold containing a sustained transforming growth factor (TGF)-beta 1-releasing nanoparticle system will promote migration and enhance differentiation of stem cells from the apical papilla (SCAP). The study aimed to develop and characterize a novel modified chitosan-based scaffold containing TGF-beta 1-releasing chitosan nanoparticles (TGF-beta 1-CSnp) to enhance migration and differentiation of SCAP. Methods: Part I concerns the synthesis and characterization of a carboxymethyl chitosan-based scaffold and TGF-beta 1-CSnp. Part II examines the effect of sustained TGF-beta 1 release from scaffold containing TGF-beta 1-CSnp on odontogenic differentiation of SCAP. Results: The scaffold demonstrated properties conducive to cellular activities. The incorporation of TGF-beta 1 in CSnp allowed sustained release of TGF-beta 1, facilitating delivery of a critical concentration of TGF-beta 1 at the opportune time. TGF-beta 1 bioactivity was maintained for up to 4 weeks. SCAP showed greater viability, migration, and biomineralization in the presence of TGF-beta 1-CSnp than in the presence of free TGF-beta 1 SCAP cultured in TGF-beta 1-CSnp + scaffold showed significantly higher dentin matrix protein-1 and dentin sialophosphoprotein signals compared with free TGF-beta 1 + scaffold or CSnp + scaffold. Conclusions: These experiments highlighted the potential of a carboxymethyl chitosan-based scaffold with growth factor releasing nanoparticles to promote migration and differentiation of SCAP. The results of this study may have direct application to improve current endodontic regenerative protocols.