Polymer Composition Modulates Dental Stem Cell Response and Mineralization in Electrospun Scaffolds for Hard Tissue Regeneration

Material selection is crucial to hard tissue regeneration, and matching scaffold properties to those of the target tissue can improve clinical outcomes. This study compared the physicochemical, mechanical, and biological performance of fibrous scaffolds fabricated from polycaprolactone (PCL), polydioxanone (PDO), and gelatin methacryloyl (GelMA) for hard tissue regeneration. Polymeric fibers were produced by electrospinning, and their morphological, physical, and mechanical properties were characterized by scanning electron microscopy (SEM, n = 2), swelling and degradation analyses (n = 8), water contact angle measurements (n = 16), and tensile testing (n = 8). In addition, periodontal ligament stem cells (PDLSCs), alveolar bone marrow stem cells (aBMSCs), and dental pulp stem cells (DPSCs) were seeded onto the scaffolds to evaluate cell spreading (n = 4), viability (n = 8), and mineralized matrix formation (n = 6). Data were analyzed using one- or two-way ANOVA followed by appropriate post hoc tests (α = 5%). All polymers formed homogeneous fibrous scaffolds, with diameters within the nanoscale range. PDO and GelMA showed higher swelling than PCL, while PCL retained approximately 95% of its initial mass after three months. PCL and PDO showed higher elongation at break, tensile strength, and Young’s modulus than GelMA. Both PDO and GelMA displayed contact angles below 90°, with GelMA showing the lowest values. In vitro, all polymers were cytocompatible: PDO and GelMA enhanced DPSC viability at 7 days, whereas GelMA produced the highest viability for PDLSCs and aBMSCs at that time point. GelMA also promoted the highest mineralized matrix formation for DPSCs and PDLSCs, with no significant differences among polymers for aBMSCs. Overall, GelMA scaffolds promoted greater cell viability and mineralized matrix formation, while PCL and PDO provided superior mechanical properties, highlighting the importance of balancing biological and mechanical requirements when designing scaffolds for hard tissue regeneration.