Affiliations: [a] Department of Orthopedics, Deqing People’s Hospital, Deqing, Zhejiang, China | [b] Department of Radiology, Deqing People’s Hospital, Deqing, Zhejiang, China
Correspondence:
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Corresponding authors: Guangjun Li, Department of Orthopedics, Deqing People’s Hospital, Deqing, Zhejiang 313200, China. E-mail: joseph06113033@126.com. Weidong Xu, Department of Orthopedics, Deqing People’s Hospital, Deqing, Zhejiang 313200, China. E-mail: zjdqxwd@126.com
Note: [†] These authors contributed equally to this work.
Abstract: BACKGROUND:Calcium phosphate cements (CPCs) are biocompatible materials that have been evaluated as scaffolds in bone tissue engineering. At present, the stem cell density of inoculation on CPC scaffold varies. OBJECTIVE:The aim of this study is to analyze the effect of seeding densities on cell growth and osteogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs) on a calcium phosphate cements (CPCs) scaffold. METHODS:BMMSCs derived from minipigs were seeded onto a CPC scaffold at three densities [1 million/mL (1M), 5 million/mL (5M) and 25 million/mL 25M)], and cultured for osteogenic induction for 1, 4 and 8 days. RESULTS:Well adhered and extended BMMSCs on the CPC scaffold showed significantly different proliferation rates within each seeding density group at different time points (P < 0.05). The number of live cells per unit area in 1M, 5M and 25M increased by 3.5, 3.9 and 2.5 folds respectively. The expression of ALP peaked at 4 days post inoculation with the fold-change being 2.6 and 2.8 times higher in 5M and 25M respectively as compared to 1M. The expression levels of OC, Coll-1 and Runx-2 peaked at 8 days post inoculation. CONCLUSIONS:An optimal seeding density may be more conducive for cell proliferation, differentiation, and extracellular matrix synthesis on scaffolds. We suggest the optimal seeding density should be 5 million/mL.
