(PR025) Analysis of the Effect of Lipopolysaccharide and Electrospun PLGA Membranes on the Behavior of Stem Cells from Apical Papilla

Objective: Electrospinning is a promising method for fabricating scaffolds, producing nanofibrous membranes from poly (lactic-co-glycolic) (PLGA) polymer, useful in pulp regeneration. However, bacteria and their by-products, such as lipopolysaccharide (LPS), may affect stem cells from apical papilla (SCAPs). This study aimed to evaluate the effect of LPS on SCAPs behavior in contact with three PLGA electrospun scaffolds.

Methods: Three PLGA 50:50 membranes were fabricated by electrospinning with concentrations of 7.5% (M1), 15% (M2), and a mixture of 6% and 12.5%, combined with 6% bovine type B skin gelatin (M3). SCAPs were cultured on the membranes in proliferation medium (PM) with or without LPS (1 µg/mL). Metabolic viability was evaluated by Alamar Blue assay after 24, 48, and 72 hours. Mineralization potential was analyzed at 21 days using Alizarin Red Staining after culturing SCAPs in differentiation medium (DM) with or without LPS (1 µg/mL). Positive and negative controls were used for comparison. Scanning electron microscopy (SEM) images were obtained after 24 hours.

Results: Viability assays showed no significant differences between groups, with or without LPS, in all experimental time points. However, the mineralization assay revealed significant differentiation in all experimental groups compared to PM, with or without LPS. In the absence of LPS, M1 exhibited the highest differentiation capacity compared to the DM group (p < 0.05). SEM images showed SCAPs in contact with the membranes.

Conclusion: None of the evaluated membranes influenced SCAPs viability. Regarding mineralization potential, the M1 membrane (7.5% PLGA), exhibited more mineralization nodules in the absence of LPS.