Driving Cartilage Formation in High-Density Human Adipose-Derived Stem Cell Aggregate and Sheet Constructs Without Exogenous Growth Factor Delivery
Driving Cartilage Formation in High-Density Human Adipose-Derived Stem Cell Aggregate and Sheet Constructs Without Exogenous Growth Factor Delivery
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DOI：
10.1089/ten.tea.2012.0551
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发表时间：
2014-12-01
影响因子：
4.1
通讯作者：
Alsberg, Eben
中科院分区：
文献类型：
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作者：
Dang, Phuong N.;Solorio, Loran D.;Alsberg, Eben
人脂肪干细胞(HASCs)是一种诱人的软骨组织工程细胞来源，可以很容易地扩增并诱导分化为软骨细胞。本研究探讨了生长因子分布和释放动力学对3DHASC构建的转化生长因子-β1明胶微球内软骨形成的影响。HASC聚集体中的微球数量、转化生长因子-β1浓度和聚合物降解率是不同的。确定了微球和转化生长因子-β1的负载浓度，其结果是糖胺聚糖(GAG)的产量与在含有转化生长因子-β1的培养液中培养的对照聚集体相当。自组装的HASC片材随后被设计用于生产更大的、更临床相关的结构。外源性转化生长因子-β1培养3周后，仅含HASC的组织块可观察到软骨的形成。重要的是，携带转化生长因子-β1微球的片材产生的GAG与外源转化生长因子-β1处理的片材相似。通过观察软骨样形态和GAG染色，组织学上证实了软骨的形成。这是首次证明hASCs在外源性转化生长因子-β1或转化生长因子-β1释放微球存在下自组装成能够形成软骨的高密度细胞片。微球掺入可以避免延长体外培养的需要，有可能使HASC片更快地植入缺损处，在体内再生软骨。
An attractive cell source for cartilage tissue engineering, human adipose-derived stem cells (hASCs) can be easily expanded and signaled to differentiate into chondrocytes. This study explores the influence of growth factor distribution and release kinetics on cartilage formation within 3D hASC constructs incorporated with transforming growth factor-beta 1 (TGF-beta 1)-loaded gelatin microspheres. The amounts of microspheres, TGF-beta 1 concentration, and polymer degradation rate were varied within hASC aggregates. Microsphere and TGF-beta 1 loading concentrations were identified that resulted in glycosaminoglycan (GAG) production comparable to those of control aggregates cultured in TGF-beta 1-containing medium. Self-assembling hASC sheets were then engineered for the production of larger, more clinically relevant constructs. Chondrogenesis was observed in hASC-only sheets cultured with exogenous TGF-beta 1 at 3 weeks. Importantly, sheets with incorporated TGF-beta 1-loaded microspheres achieved GAG production similar to sheets treated with exogenous TGF-beta 1. Cartilage formation was confirmed histologically via observation of cartilage-like morphology and GAG staining. This is the first demonstration of the self-assembly of hASCs into high-density cell sheets capable of forming cartilage in the presence of exogenous TGF-beta 1 or with TGF-beta 1-releasing microspheres. Microsphere incorporation may bypass the need for extended in vitro culture, potentially enabling hASC sheets to be implanted more rapidly into defects to regenerate cartilage in vivo.