A first approach to evaluate the cell dose in highly porous scaffolds by using a nondestructive metabolic method

Background: In cell-based therapies, in vitro studies on biomimetic cell-scaffold constructs can facilitate the determination of the cell dose, a key factor in guaranteeing the effectiveness of the treatment. However, highly porous scaffolds do not allow a nondestructive evaluation of the cell number. Our objective was to develop a nondestructive method for human mesenchymal stem cells dose evaluation in a highly porous scaffold for bone regeneration. Materials & measurement method: Proliferation trend of human mesenchymal stem cells on Biocoral (R) scaffolds was measured by a resazurin-based assay here optimized for 3D cultures. The method allows to noninvasively follow the cell proliferation on biocorals over 3 weeks with very high reproducibility. Conclusion: This reliable method could be a powerful tool in cell-based therapies for cell dose determination. Stem cells regenerate damaged tissues when transplanted into the patient within matrices mimicking the tissues architecture and mechanical properties. Cell number needs to be appropriate to allow the cell survival in the new environment and to stimulate the cell differentiation into the new tissue. In vitro experiments give important hints to determine the appropriate number to transplant in the patient: in this study cells are grown on highly porous matrices for bone regeneration and their number is monitored over time by a method which does not perturb the system and which was here optimized and evaluated as highly reliable.