Chitosan nanoparticles promote TGF-Β1 release from dentin and support stem cell attachment and differentiation in vitro.

To evaluate, in vitro, the effect of chitosan nanoparticles (CSNPs), 17 % EDTA and 10 % citric acid (CA) on dentin-derived Transforming Growth Factor-Beta (TGF-β1) release, Dental Stem Cells SV40 (DSCS) morphology, attachment and osteogenic/odontogenic differentiation. TGF-β1 release after 24 h was quantified by ELISA following 10-min treatment of 30 root segments with CSNPs, EDTA or CA. DSCS attachment and morphology were assessed by scanning electron microscopy (SEM) after 3 days of culture on conditioned dentin surfaces. Differentiation was evaluated using alizarin red staining and COL1A1 expression following exposure to 1:10,000 dilutions of each solution or 5 ng/mL TGF-β1. Data were analysed using one-way ANOVA with Tukey's post hoc test (α=0.05). CSNPs induced significantly higher TGF-β1 release compared to EDTA (p = 0.0480) and CA (p = 0.0045). SEM analysis showed comparable spindle-shaped DSCS morphology and attachment across all groups. CSNPs demonstrated the highest calcium deposition followed by the TGF-β1 group, while minimal deposition was observed with CA and EDTA. TGF-β1 treatment resulted in significantly higher COL1A1 expression compared to EDTA (p = 0.0258) and CA (p = 0.0323), while CSNPs showed a trend toward higher expression. CSNPs enhanced TGF-β1 release compared to 17 % EDTA and 10 % CA while supporting comparable DSCS morphology and attachment. CSNPs and TGF-β1 showed enhanced osteogenic/odontogenic differentiation compared to 17 % EDTA and 10 % CA. CSNPs may represent a potential alternative dentin-conditioning agent capable of enhancing growth factor release and supporting favourable cellular responses; however, further studies are required to confirm their biocompatibility and clinical applicability.