Division of Orthodontics, College of Dentistry, Ohio State University, Columbus, Ohio, United States of America.
PLoS One. 2013 Sep 5;8(9):e74672. doi: 10.1371/journal.pone.0074672. eCollection 2013.
Bone regeneration through distraction osteogenesis (DO) is promising but remarkably slow. To accelerate it, autologous mesenchymal stem cells have been directly injected to the distraction site in a few recent studies. Compared to direct injection, a scaffold-based method can provide earlier cell delivery with potentially better controlled cell distribution and retention. This pilot project investigated a scaffold-based cell-delivery approach in a porcine mandibular DO model.
Eleven adolescent domestic pigs were used for two major sets of studies. The in-vitro set established methodologies to: aspirate bone marrow from the tibia; isolate, characterize and expand bone marrow-derived mesenchymal stem cells (BM-MSCs); enhance BM-MSC osteogenic differentiation using FGF-2; and confirm cell integration with a gelatin-based Gelfoam scaffold. The in-vivo set transplanted autologous stem cells into the mandibular distraction sites using Gelfoam scaffolds; completed a standard DO-course and assessed bone regeneration by macroscopic, radiographic and histological methods. Repeated-measure ANOVAs and t-tests were used for statistical analyses.
From aspirated bone marrow, multi-potent, heterogeneous BM-MSCs purified from hematopoietic stem cell contamination were obtained. FGF-2 significantly enhanced pig BM-MSC osteogenic differentiation and proliferation, with 5 ng/ml determined as the optimal dosage. Pig BM-MSCs integrated readily with Gelfoam and maintained viability and proliferative ability. After integration with Gelfoam scaffolds, 2.4-5.8×10(7) autologous BM-MSCs (undifferentiated or differentiated) were transplanted to each experimental DO site. Among 8 evaluable DO sites included in the final analyses, the experimental DO sites demonstrated less interfragmentary mobility, more advanced gap obliteration, higher mineral content and faster mineral apposition than the control sites, and all transplanted scaffolds were completely degraded.
It is technically feasible and biologically sound to deliver autologous BM-MSCs to the distraction site immediately after osteotomy using a Gelfoam scaffold to enhance mandibular DO.
通过牵引成骨术（DO）进行骨再生具有很大的潜力，但速度非常缓慢。为了加速骨再生，在最近的一些研究中，已将自体间充质干细胞直接注射到牵引部位。与直接注射相比，支架基方法可以更早地输送细胞，并且可以更有效地控制细胞的分布和保留。本研究项目在猪下颌骨 DO 模型中研究了基于支架的细胞输送方法。
使用 11 只未成年家猪进行了两项主要研究。在体外研究中，建立了从胫骨抽吸骨髓；分离、鉴定和扩增骨髓间充质干细胞（BM-MSCs）；使用 FGF-2 增强 BM-MSC 成骨分化；以及确认细胞与基于明胶的 Gelfoam 支架整合的方法。在体内研究中，使用 Gelfoam 支架将自体干细胞移植到下颌骨牵引部位；完成标准 DO 疗程，并通过宏观、射线照相和组织学方法评估骨再生。采用重复测量方差分析和 t 检验进行统计学分析。
从抽吸的骨髓中，从造血干细胞污染中纯化出了多能、异质的 BM-MSCs。FGF-2 显著增强了猪 BM-MSC 的成骨分化和增殖能力，确定 5ng/ml 为最佳剂量。猪 BM-MSCs 与 Gelfoam 结合紧密，保持活力和增殖能力。与 Gelfoam 支架整合后，每个实验性 DO 部位移植了 2.4×107 至 5.8×107 个自体 BM-MSCs（未分化或分化）。在最终分析中包括的 8 个可评估的 DO 部位中，实验性 DO 部位的断端间活动度较小，间隙闭合较快，矿物质含量较高，矿物质沉积较快，所有移植的支架均完全降解。
使用 Gelfoam 支架在骨切开术后立即将自体 BM-MSCs 输送到牵引部位，以增强下颌骨 DO，在技术上是可行的，在生物学上是合理的。
