Structured co-culture of stem cells and chondrocytes for spinal disc repair

描述（由申请人提供）：该基金的总体目标是通过椎间盘组织工程开发治疗轴性背痛的改进方法。我们以前的研究表明，椎间盘退变是核细胞功能低下的表现。成体间充质干细胞（MSC）是一种有吸引力的细胞核再生的细胞来源，然而，它们的分化和功能需要优化以在具有挑战性的退行性椎间盘环境中茁壮成长。为了提高MSC在体内的弹性，我们发现了一种新的共培养系统，其中MSC与软骨细胞一起包装在球形构型中。这种双层结构允许同型和异型细胞相互作用，模拟冷凝（细胞聚集体形成）和诱导（成熟组织层指导幼稚组织层的分化）的发育过程。我们正在进行的研究表明，双层细胞团（BCP）在体外条件下具有上级基质合成和基因表达，如退化椎间盘。 鉴于BCP结果的前景，我们现在在目标1中建议优化小BCP配置以进行微创椎间盘内注射。在目标3中，我们将确定优化的BCP是否导致椎间盘损伤的小动物模型中形态学相关的改善（与适当的对照条件相比）。

DESCRIPTION (provided by applicant): The overall goal of this grant is to develop improved methods of treating axial back pain via intervertebral disc tissue engineering. Our previous research indicates that disc degeneration is a manifestation of poor nucleus cell function. Adult mesenchymal stem cells (MSCs) are an attractive cell source for nucleus rejuvenation, however, their differentiation and function need to be optimized to thrive in the challenging degenerate disc environment. To improve MSC resilience in vivo, we discovered a novel co-culture system where MSCs are packaged in a spherical configuration with chondrocytes. This bi-laminar structure allows for homotypic and heterotypic cellular interactions that mimic the developmental processes of condensation (where cell aggregates form) and induction (where a mature tissue layer directs the differentiation of a na¿ve one). Our ongoing studies demonstrate that bi-laminar cell pellets (BCPs) have superior matrix synthesis and gene expression under in vitro conditions like those of the degenerate disc. Given the promising BCP results, we now propose in Aim 1 to optimize a small BCP configuration to for minimally-invasive intradiscal injection. In Aim 3 we will determine whether optimized BCPs lead to morphologically-relevant improvements (as compared to appropriate control conditions) within a small animal model of disc injury.