Effects of photobiomodulation on stem cells from human exfoliated deciduous teeth cultured on electrospun polylactic...

This study aimed to evaluate the short-term effects of photobiomodulation (PBM) on stem cells from human exfoliated deciduous teeth (SHEDs) cultured on electrospun polylactic acid (PLA) microfibrous scaffolds. The scaffolds were characterized by scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry. SHEDs were seeded onto the scaffold surface and assigned to three groups: nonirradiated control (C), L0.5 (0.5 J/cm²), and L1 (1.0 J/cm²). PBM was delivered with a 660 nm diode laser at 0 and 48 h after the initial irradiation time point. Cell metabolic activity was assessed at 24, 48, and 72 h using the Alamar Blue assay. Qualitative viable-cell distribution and cell-scaffold interactions were evaluated by Live/Dead staining and scanning electron microscopy, respectively. SHEDs remained viable on the PLA microfibrous scaffold and showed increasing metabolic activity over time. Compared with the control group, L1 presented higher Alamar Blue reduction values at 48 and 72 h, with the highest metabolic activity observed at 72 h. Live/Dead images showed qualitatively more extensive viable-cell colonization of the scaffold surface in the irradiated groups, without an apparent increase in dead-cell staining. Scanning electron microscopy revealed SHED adhesion to the microfibrous scaffold in all groups and qualitatively more extensive cell coverage after irradiation, particularly in L1. Electrospun PLA microfibrous scaffolds supported short-term SHED culture, and PBM at 1.0 J/cm² increased SHED metabolic activity and was associated with favorable qualitative cell-scaffold interactions. These findings provide preliminary support for PBM as an adjunctive biophysical strategy for improving early cellular responses in SHED-seeded electrospun PLA scaffolds.