Optimized PLA/MWCNT nanocomposite scaffolds enhance SHED differentiation for dentin–pulp complex regeneration: an in vitro evaluation

Regeneration of the dentin–pulp complex remains a challenge in endodontics due to the limited capacity of conventional treatments to restore full biological function. Stem cell-based strategies using biocompatible scaffolds have been explored as alternative approaches, particularly with stem cells from human exfoliated deciduous teeth (SHED), which exhibit notable odontogenic potential. In this in vitro pilot study, we aimed to investigate the in vitro differentiation behavior of SHED cells cultured on a polylactic acid (PLA) scaffold reinforced with 0.5% multi-walled carbon nanotubes (MWCNTs), a formulation previously optimized for mechanical integrity, biodegradability, and cytocompatibility. PLA/0.5% MWCNT scaffolds were fabricated and seeded with SHED obtained from a single healthy male donor. Cell viability and proliferation were assessed by trypan blue exclusion and DAPI staining. Odontogenic and osteogenic differentiation was evaluated by qRT-PCR and Western blotting for DSPP and DMP1, ALP immunofluorescence, and Alizarin Red S staining for mineral deposition. SHED maintained viability (∼70%) and exhibited increased expression of lineage-specific markers and mineralization on PLA/MWCNT scaffolds compared to non-scaffold controls (p < 0.01). While limited by the in vitro setting and single-donor origin, these results provide insights into the potential of MWCNT-reinforced PLA scaffolds for use in dental tissue engineering applications.