Polyglycolic acid-polylactic acid scaffold response to different progenitor cell in vitro cultures: a demonstrative and comparative X-ray synchrotron radiation phase-contrast microtomography study.

Spatiotemporal interactions play important roles in tissue development and function, especially in stem cell-seeded bioscaffolds. Cells interact with the surface of bioscaffold polymers and influence material-driven control of cell differentiation. In vitro cultures of different human progenitor cells, that is, endothelial colony-forming cells (ECFCs) from a healthy control and a patient with Kaposi sarcoma (an angioproliferative disease) and human CD133+ muscle-derived stem cells (MSH 133+ cells), were seeded onto polyglycolic acid-polylactic acid scaffolds. Three-dimensional (3D) images were obtained by X-ray phase-contrast microtomography (micro-CT) and processed with the Modified Bronnikov Algorithm. The method enabled high spatial resolution detection of the 3D structural organization of cells on the bioscaffold and evaluation of the way and rate at which cells modified the construct at different time points from seeding. The different cell types displayed significant differences in the proliferation rate. In conclusion, X-ray synchrotron radiation phase-contrast micro-CT analysis proved to be a useful and sensitive tool to investigate the spatiotemporal pattern of progenitor cell organization on a bioscaffold.

Organization of extracellular matrix fibers within polyglycolic acid-polylactic acid scaffolds analyzed using X-ray synchrotron-radiation phase-contrast micro computed tomography.

Spatiotemporal organized patterns of cell surface-associated and extracellular matrix (ECM)-embedded molecules play important roles in the development and functioning of tissues. ECM proteins interact with the surface of bioscaffold polymers and influence material-driven control of cell differentiation., Using X-ray phase-contrast micro computed tomography (microCT), we visualized the three-dimensional (3D) image of ECM organization after in vitro seeding of bone marrow-derived human and murine mesenchymal stem cells (MSCs) induced to myogenic differentiation, labelled with iron oxide nanoparticles, and seeded onto polyglycolic acid-polylactic acid scaffolds. X-ray microCT enabled us to detect with high spatial resolution the 3D structural organization of ECM within the bioscaffold and how the presence of cells modified the construct arrangement. Species-specific differences between the matrix produced by human and murine cells were observed. In conclusion, X-ray synchrotron radiation microCT analysis appeared to be a useful tool to identify the spatiotemporal pattern of organization of ECM fibers within a bioscaffold.