Effects of a Novel Inoculation Method on Cell Distribution, Mineralization, and Vascularization of Tissue-Engineered...

Objective: Despite some potential advantages, tissue-engineered constructs have low therapeutic efficacy after transplantation into bone defect sites due to uneven distribution of seed cells, which presents a major obstacle in a clinical setting. The aim of this study was to improve cell distribution within the scaffold, to increase seeding efficiency, to facilitate tissue ingrowth and vascularization of the resultant grafts, and finally to boost the successful rate of transplantation. Approach: A syringe-aided inoculation method was designed to anchor bone marrow stromal cells (BMSCs) onto the central pores of the chitosan scaffold by repeat positive aspiration. The cell distribution, cell number, vascularization and mineralization at the central region of the tissue-engineered constructs treated by syringe-aided and regular two-side inoculation methods were evaluated side by side using the WST-8, immunofluorescence staining of CD31 and von Kossa staining. Results: The tissue-engineered constructs treated by the syringe-aided inoculation methods exhibited a larger number of BMSCs with uniform distribution, as well as more robust vascularization and mineralization in the central regions when compared with those treated by the two-side inoculation method both in vitro and in vivo. Innovation: This is the first time that the influence of a syringe-aided inoculation method has been evaluated with respect to the vascularization and mineralization of implanted grafts. Conclusion: The syringe-aided inoculation methods used in this study might provide an approach through which to improve cell distribution within the scaffold, facilitate the subsequent tissue ingrowth into the scaffold, and promote the vascularization and mineralization of tissue-engineered grafts.