Osteogenic differentiation of equine cord blood multipotent mesenchymal stromal cells within coralline hydroxyapatite scaffolds in vitro

Objective: To investigate the osteogenic differentiation potential of equine umbilical cord blood-derived multipotent mesenchymal stromal cells (CB-MSC) within coralline hydroxyapatite scaffolds cultured in osteogenic induction culture medium. Methods: Scaffolds seeded with equine CB-MSC were cultured in cell expansion culture medium (control) or osteogenic induction medium (treatment). Cell viability and distribution were confirmed by the MTT cell viability assay and DAPI nuclear fluorescence staining, respectively. Osteogenic differentiation was evaluated after 10 days using reverse transcription polymerase chain reaction, alkaline phosphatase activity, and secreted osteocalcin concentration. Cell morphology and matrix deposition were assessed by scanning electron microscopy (SEM) after 14 days in culture. Results: Cells showed viability and adequate distribution within the scaffold. Successful osteogenic differentiation within the scaffolds was demonstrated by the increased expression of osteogenic markers such as Runx2, osteopontin, osteonectin, collagen IA; increased levels of alkaline phosphatase activity; increased osteocalcin protein secretion and bone-like matrix presence in the scaffold pores upon SEM evaluation. Clinical significance: These results demonstrate that equine CB-MSC maintain viability and exhibit osteogenic potential in coralline hydroxyapatite scaffolds when induced in vitro. Equine CB-MSC scaffold constructs deserve further investigation for their potential role as biologically active fillers to enhance bone-gap repair in the horse.