Department of Otolaryngology-Head & Neck Surgery, University of Virginia, PO Box 800713, Charlottesville, VA 22908, USA.
Laryngoscope. 2010 May;120(5):895-901. doi: 10.1002/lary.20624.
OBJECTIVES/HYPOTHESIS: Advances in bone repair have focused on the minimally-invasive delivery of tissue-engineered bone (TEB). A promising injectable biopolymer of chitosan and inorganic phosphates was seeded with mesenchymal stem cells (MSCs) and a bone growth factor (BMP-2), and evaluated in a rat calvarial critical size defect (CSD). Green fluorescent protein (GFP)-labeled MSCs are used to evaluate patterns of cell viability and proliferation.
Prospective, controlled trial in an animal model.
In 30 male rats, 8-mm calvarial CSDs were created, and divided into five groups of six animals each. In the experimental groups, the defects were injected with either chitosan gel, gel loaded with MSCs (0.3 x 10(6) cells/defect), gel loaded with BMP-2 (2 microg/defect), or gel loaded with both MSC and BMP-2. In the control group, the defect was left untreated. At 4 weeks, in vivo microcomputed tomography (micro-CT) analysis was performed. At 8 weeks, calvarial specimens were examined by micro-CT, histology, and immunohistochemistry.
New areas of bone growth were seen in the defects of all treated animals. Micro-CT analysis revealed a significant (P < .001) time-dependent increase in the regeneration of bone volume and bone area in defects treated with gel/MSC/BMP-2 as compared to all other groups. Histological analysis confirmed this difference. GFP-labeled TEB was detected within the areas of new bone, indicating cell viability and contribution to new bone growth by the injected MSC.
This study demonstrates that an injectable form of TEB using a chitosan gel, MSC, and BMP-2 can enhance bone formation in a rat calvarial CSD.
目的/假设：骨修复的进展集中在组织工程骨（TEB）的微创输送上。一种有前途的壳聚糖和无机磷酸盐的可注射生物聚合物与间充质干细胞（MSCs）和骨生长因子（BMP-2）一起接种，并在大鼠颅骨临界尺寸缺陷（CSD）中进行了评估。绿色荧光蛋白（GFP）标记的 MSCs 用于评估细胞活力和增殖模式。
动物模型中的前瞻性、对照试验。
在 30 只雄性大鼠中，创建了 8-mm 颅骨 CSD，并将其分为五组，每组 6 只动物。在实验组中，缺陷部位注射壳聚糖凝胶、负载 MSC（0.3 x 10(6)个细胞/缺陷）的凝胶、负载 BMP-2（2 microg/缺陷）的凝胶或负载 MSC 和 BMP-2 的凝胶。在对照组中，缺陷未处理。在 4 周时，进行体内微计算机断层扫描（micro-CT）分析。在 8 周时，通过 micro-CT、组织学和免疫组织化学检查颅骨标本。
所有治疗动物的缺陷中都出现了新的骨生长区域。micro-CT 分析显示，与所有其他组相比，用凝胶/MSC/BMP-2 治疗的缺陷中，骨体积和骨面积的再生有显著的（P <.001）时间依赖性增加。组织学分析证实了这一差异。在新骨区域检测到 GFP 标记的 TEB，表明细胞活力和注入的 MSC 对新骨生长的贡献。
本研究表明，使用壳聚糖凝胶、MSC 和 BMP-2 的可注射 TEB 形式可以增强大鼠颅骨 CSD 中的骨形成。
