Effect of hUCMSC-seeded hydroxyapatite-chitosan scaffolds on immunomodulatory cytokine expression during alveolar socket healing: an in vivo study.

Alveolar socket preservation is important because post-extraction ridge resorption may compromise future implant placement, periodontal support, and prosthetic stability. Tissue engineering using biomaterial scaffolds and mesenchymal stem cells (MSCs) is a promising strategy to modulate inflammation and support socket healing. Hydroxyapatite-chitosan (HA-Chi) scaffolds are biocompatible and osteoconductive, while human umbilical cord mesenchymal stem cells (hUCMSCs) have regenerative and immunomodulatory properties. This study evaluated the effects of hUCMSC-seeded HA-Chi scaffolds on interleukin-10 (IL-10) and interleukin-1β (IL-1β) expression during alveolar socket healing. In this in vivo study, 63 male Wistar rats with post-extraction alveolar socket defects were randomly assigned to three groups: untreated control (C), HA-Chi scaffold alone (T1), and hUCMSC-seeded HA-Chi scaffold (T2) (n = 21/group; n = 7/subgroup at 7, 14, and 28 days post-extraction). IL-10 and IL-1β expression were assessed by immunohistochemistry (IHC). Phenotypic characterization confirmed positive expression of CD73, CD90, and CD105 and negative expression of CD45. Data were analyzed using two-way ANOVA for group (Control, T1, T2), time (Days 7, 14, 28), and group × time effects, followed by Tukey's HSD post hoc test; effect sizes were reported as partial eta-squared (η²p). Two-way ANOVA showed significant group and time effects for both cytokines (all p < 0.001), with large group effect sizes (IL-10: η²p = 0.646; IL-1β: η²p = 0.545). The group × time interaction was non-significant for both IL-10 (p = 0.799) and IL-1β (p = 0.577), indicating consistent treatment effects across all time points. The T2 group showed the highest IL-10 and lowest IL-1β expression at all-time points. hUCMSC-seeded HA-Chi scaffolds enhanced post-extraction immunomodulation by upregulated IL-10 and downregulated IL-1β. These findings support the potential of hUCMSC-seeded HA-Chi scaffolds as an immunomodulatory strategy for alveolar socket healing; however, direct evidence of bone regeneration through histomorphometric and osteogenic marker assessment remains to be established.