In vitro interaction of human Wharton's jelly mesenchymal stem cells with biomimetic 3D scaffold

Study of cell-biomaterial interaction is a crucial aspect of bone tissue engineering to find a state-of-the-art functional substitute. In present study, the Wharton's jelly mesenchymal stem cells (hWJ-MSCs) behavior on three-dimensional biomimetic nano-hydroxyapatite/chitosan/gelatin (nHA/CS/Gel) scaffolds was investigated. The outcome was assessed by histological, biochemical and morphological tests. Results indicated that hWJ-MSCs attached onto the scaffold surface through membrane filopodia, uniformly spread throughout the contacting surface. It only took 3 days for the seeded cells to appear deep inside the scaffold, reflecting proper hWJ-MSCs adhesion and migration, evidenced by both scanning electron microscope and hematoxilin and eosin assessments. Additionally, the present fabricated nHA/CS/Gel scaffold proved to be non-toxic as it supported cell proliferation measured by 3-(4,5-dimethylthiazoyl-2-yl)-2,5-diphenyltetrazolium bromide assay. Moreover, 3-week culture of hWJ-MSCs on scaffolds, immersed in osteogenic medium, rendered the microenvironment in favor of hWJ-MSCs differentiation into osteoblast cells and extracellular matrix secretion. Finally, osteoblasts were immunologically positive for various osteogenic markers including osteocalcin, osteopontin, osteonectin, and alkaline phosphatase. Present findings indicate that nHA/CS/Gel scaffold appropriately harbored hWJ-MSCs, stimulating their growth, migration, proliferation, and differentiation. hWJ-MSCs-loaded nHA/CS/gel substitute may therefore be considered as a suitable platform for the rising demand in in vivo bone repair studies. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1166-1175, 2019.