Pre‐culture period of mesenchymal stem cells in osteogenic media influences their in vivo bone forming potential

Abstract

The objective of this study was to investigate if the in vitro pre-culture period in osteogenic media of rat mesenchymal stem cells (MSCs), influences their ability to regenerate bone when implanted in a critical size cranial defect. MSCs were harvested from the bone marrow of 6-8 weeks old male Fisher rats and expanded in vitro in osteogenic media for different time periods (4, 10, and 16 days) in tissue culture plates (TCP), seeded on sintered titanium fiber meshes without the extracellular matrix (ECM) generated in vitro, and implanted in the rat cranium after 12 h. Thirty two adult Fisher rats received the implants, divided in four groups. Three groups were implanted with cells cultured for 4, 10, or 16 days in osteogenic media and at that time their alkaline phosphatase activity and mineral deposition denoted that they were at different stages of their osteoblastic maturation (undifferentiated MSC, committed, and mature Osteoblasts, respectively). MSCs cultured without osteogenic media for 6 days were used as controls. The constructs were retrieved 4 weeks later and processed for histomorphometric analysis. Implants seeded with cells that have been cultured with osteogenic media for only 4 days revealed the highest bone formation. The lowest bone formation was obtained with the implants seeded with MSCs cultured for 16 days in the presence of osteogenic media. The results of this study suggested that the in vitro pre-culture period of MSCs is a critical factor for their ability to regenerate bone when implanted to an orthotopic site.

Bone Tissue Engineering with Multilayered Scaffolds—Part I: An Approach for Vascularizing Engineered Constructs In Vivo

“…Preculture period of 4 days has been identified as optimal for bone formation in vivo. 46 The role of fiber diameter on porosity and cell infiltration has also been reported previously. 24 Even though the nanofibers used as osteogenic layers were <100 mm in thickness, cells remained as a single layer above the wafer.…”

Enhanced Osteogenesis in Cocultures with Human Mesenchymal Stem Cells and Endothelial Cells on Polymeric Microfiber Scaffolds

“…39 In this study, it was observed that precultured and non-precultured cocultures presented an ALP activity significantly higher than corresponding monocultures. The enhancement of ALP activity in cocultures may be mediated by p38 mitogen-activated protein kinase-dependent stabilization of mRNA for ALP.…”

Repair of critical-size defects with autogenous periosteum-derived cells combined with bovine anorganic apatite/collagen: an experimental study in rat calvaria

“…however, long-term contact (6 months) between trabecular bonederived cells and natural apatite (anorganic bovine bone) grafted in human maxilla inhibits osteoblast-like phenotype in vitro (24). Further longer pre-culture periods have a critical role in differentiation process for lead to a progressively diminishing of osteoinductivity (25). In this way, the worst performance of the xenograft with cells could be explained by (i) unfavorable adhesion and the challenge to differentiate PDC upon inappropriate material as cell carrier during the experimental period or (ii) inhibition of cellular proliferation and osteoinductive potential due to long pre-culture period in osteogenic media in vitro (6 days) before implantation into an orthotopic site (rcCsD) for in vivo study.…”