Bioengineered polycaprolactone nanofibers co-loaded with RGD and asiatic acid for dentin-pulp regeneration

Regenerating the pulp-dentin complex remains a major challenge in restorative dentistry. Biomimetic nanofibrous membranes provide a promising therapeutic strategy by serving as resorbable scaffolds that facilitate cell infiltration, vascularization, and dentin bridge formation within the dentin-pulp complex. In this study, polycaprolactone (PCL) nanofibers incorporated with Arg-Gly-Asp (RGD) peptides and Asiatic acid (AA) were synthesized via electrospinning.

The nanofibers were successfully synthesized by electrospinning, with RGD and AA integrated into a PCL matrix. The scaffolds were characterized using scanning electron microscopy (SEM) for morphology, Fourier-transform infrared spectroscopy (FTIR) to evaluate chemical interactions, and contact angle analysis for surface wettability. The mechanical strength, thermal stability, and antibacterial activity against Enterococcus faecalis were also evaluated. Dental pulp stem cells (DPSCs) were used to assess biocompatibility through MTT assay, cell migration through scratch assay, and expression of odontogenic and angiogenic markers using qPCR. The study investigated dentin remineralization using micro-computed tomography and Vickers microhardness testing methods.

The RGD and AA co-loaded nanofiber exhibited an effective performance, with a tensile strength of 7.18 MPa and excellent thermal stability. The antibacterial analysis revealed 77.11% inhibition of E. faecalis for the co-loaded nanofibers, with no detrimental effects on DPSC viability. The RGD and AA nanofiber demonstrated the highest mineral density recovery of 76.21%, and the treated dentin samples exhibited a 3.9-fold increase in microhardness compared to the control. Gene expression analysis revealed significant upregulation of odontogenic markers (DSPP, DMP1) and the angiogenic marker (VEGF) in cells cultured with the RGD and AA nanofiber, confirming its biological activity in promoting cellular differentiation.

The developed RGD and AA co-loaded PCL nanofibrous membrane exhibited excellent biocompatibility, antibacterial efficacy, upregulated gene expression supporting odontogenic responses, and mineral recovery, highlighting its potential as a bioactive scaffold for dentin-pulp complex regeneration.