Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, Baltimore, MD 21201, USA.
Biomaterials. 2010 May;31(14):3848-57. doi: 10.1016/j.biomaterials.2010.01.093. Epub 2010 Feb 10.
Human bone marrow mesenchymal stem cells (hBMSCs) require an invasive procedure to harvest, and have lower self-renewal potential with aging. Umbilical cord mesenchymal stem cells (hUCMSCs) are a relatively new stem cell source; this study reveals a self-setting and load-bearing calcium phosphate construct that encapsulates these stem cells. The flexural strength (mean+/-sd; n=5) of the hUCMSC-encapsulating calcium phosphate cement (CPC) increased from (3.5+/-1.1) MPa without polyglactin fibers, to (11.7+/-2.1) MPa with 20% of polyglactin fibers (p<0.05). hUCMSCs attached to the bone mineral-mimicking scaffold in the osteogenic media and differentiated down the osteogenic lineage, yielding elevated alkaline phosphatase (ALP) and osteocalcin (OC) gene expressions. ALP and OC on the CPC-fiber scaffold was 2-fold those on CPC control without fibers. hUCMSCs encapsulated inside the scaffolds retained excellent viability and cell density. The encapsulated hUCMSCs inside four different constructs successfully differentiated down the osteogenic lineage and synthesized bone minerals, as confirmed by mineral staining, SEM, and XRD. The percentage of mineral area synthesized by the encapsulated hUCMSCs increased from about 3% at day-7, to 12% at day-21 (p<0.05). In conclusion, this study demonstrated that hUCMSCs encapsulated in the bioengineered scaffolds osteo-differentiated and synthesized bone minerals. The self-setting CPC-chitosan-fiber scaffold supported the viability and osteogenic differentiation of the encapsulated hUCMSCs, and had mechanical strength matching that of cancellous bone.
人骨髓间充质干细胞（hBMSCs）需要通过有创程序进行采集，并且随着年龄的增长其自我更新能力会降低。脐带间充质干细胞（hUCMSCs）是一种相对较新的干细胞来源；本研究揭示了一种自设定和承载能力的磷酸钙构建体，可封装这些干细胞。封装 hUCMSC 的磷酸钙水泥（CPC）的弯曲强度（平均值+/-标准差；n=5）从没有聚丙交酯纤维时的（3.5+/-1.1）MPa 增加到含有 20%聚丙交酯纤维时的（11.7+/-2.1）MPa（p<0.05）。hUCMSCs 在成骨培养基中附着在骨矿物质模拟支架上，并沿着成骨谱系分化，导致碱性磷酸酶（ALP）和骨钙素（OC）基因表达升高。在含有纤维的 CPC 纤维支架上的 ALP 和 OC 是没有纤维的 CPC 对照的 2 倍。封装在支架内的 hUCMSCs 保持良好的活力和细胞密度。封装在支架内的 hUCMSCs 成功地沿着成骨谱系分化并合成骨矿物质，这通过矿化染色、SEM 和 XRD 得到证实。封装在 hUCMSCs 内的四种不同构建体中合成的矿物质面积百分比从第 7 天的约 3%增加到第 21 天的 12%（p<0.05）。总之，本研究表明，封装在生物工程支架内的 hUCMSCs 向成骨分化并合成骨矿物质。自设定的 CPC-壳聚糖纤维支架支持封装的 hUCMSCs 的活力和成骨分化，并具有与松质骨相匹配的机械强度。
