Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, USA.
Spine (Phila Pa 1976). 2012 May 1;37(10):813-8. doi: 10.1097/BRS.0b013e31823b055f.
This study explores the use of bilaminar coculture pellets of mesenchymal stem cells (MSCs) and nucleus pulposus cells (NPCs) as a cell-based therapy for intervertebral disc regeneration. The pellets were tested under conditions that mimic the degenerative disc.
Our goal was to optimize our cell-based therapy in vitro under conditions representative of the eventual diseased tissue.
Harnessing the potential of stem cells is an important strategy for regenerative medicine. Our approach directed the behavior of stem cells by mimicking embryonic processes underlying cartilage and intervertebral disc development. Prior experiments have shown that bilaminar coculture can help differentiate MSC and substantially improve new matrix deposition.
We have designed a novel spherical bilaminar cell pellet (BCP) where MSCs are enclosed in a shell of NPC. There were 3 groups: MSC, NPC, and BCP. The pellets were tested under 3 different culture conditions: 1) in a bioreactor that provides pressure and hypoxia (mimicking normal disc conditions): 2) with inflammatory cytokines (IL-1b and TNF-a); and 3) a bioreactor with inflammation (mimicking painful disc conditions).
When cultured in the bioreactor, the NPC pellets produced significantly more glycosaminoglycans (GAGs) per cell than the other groups: 70% to 80% more than the BCP and the MSC alone. When cultured in an inflammatory environment, the MSC and BCP groups produced 30% to 34% more GAGs per cell than NPC (P < 0.05). When the pellets were cultured in a bioreactor with inflammation, the BCP made 25% more GAGs per cell than the MSC and 57% more than the NPC (P < 0.05).
This study shows that BCPs outperform controls in a simulated degenerated disc environment. Adapting inductive mechanisms from development to trigger differentiation and restore diseased tissue has many advantages. As opposed to strategies that require growth factor supplements or genetic manipulations, our method is self-sustaining, targeted, and minimally invasive injection.
本研究探索了使用间充质干细胞（MSCs）和髓核细胞（NPCs）的双层共培养微球作为一种基于细胞的治疗方法，用于椎间盘再生。这些微球在模拟退行性椎间盘的条件下进行了测试。
我们的目标是在代表终末病变组织的条件下优化我们的基于细胞的治疗方法。
利用干细胞的潜力是再生医学的重要策略。我们的方法通过模拟胚胎过程来引导干细胞的行为，这些胚胎过程是软骨和椎间盘发育的基础。先前的实验表明，双层共培养可以帮助 MSC 分化，并显著改善新基质的沉积。
我们设计了一种新型的球形双层细胞微球（BCP），其中 MSC 被包裹在 NPC 壳内。有 3 组：MSC、NPC 和 BCP。这些微球在 3 种不同的培养条件下进行了测试：1）在提供压力和缺氧的生物反应器中（模拟正常椎间盘条件）；2）用炎症细胞因子（IL-1b 和 TNF-a）；3）在有炎症的生物反应器中（模拟疼痛椎间盘条件）。
在生物反应器中培养时，NPC 微球每细胞产生的糖胺聚糖（GAG）比其他组多 70%至 80%：比 BCP 和 MSC 单独培养多 70%至 80%。在炎症环境中培养时，MSC 和 BCP 组每细胞产生的 GAG 比 NPC 多 30%至 34%（P<0.05）。当微球在有炎症的生物反应器中培养时，BCP 每细胞产生的 GAG 比 MSC 多 25%，比 NPC 多 57%（P<0.05）。
本研究表明，BCP 在模拟退行性椎间盘环境中的表现优于对照组。从发育中适应诱导机制来触发分化并恢复病变组织有许多优势。与需要生长因子补充或基因操作的策略相比，我们的方法是自我维持的、靶向的和微创注射。
