Department of Obstetrics and Gynecology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, Illinois, USA.
Tissue Eng Part A. 2020 Jul;26(13-14):720-732. doi: 10.1089/ten.tea.2020.0037. Epub 2020 Jun 30.
The physical properties of the ovarian extracellular matrix (ECM) regulate the function of ovarian cells, specifically the ability of the ovary to maintain a quiescent primordial follicle pool while allowing a subset of follicles to grow and mature in the estrous cycle. Design of a long-term, cycling artificial ovary has been hindered by the limited information regarding the mechanical properties of the ovary. In particular, differences in the mechanical properties of the two ovarian compartments, the cortex and medulla, have never been quantified. Shear wave (SW) ultrasound elastography is an imaging modality that enables assessment of material properties, such as the mechanical properties, based on the velocity of SWs, and visualization of internal anatomy, when coupled with B-mode ultrasound. We used SW ultrasound elastography to assess whole, bovine ovaries. We demonstrated, for the first time, a difference in mechanical properties, as inferred from SW velocity, between the cortex and medulla, as measured along the length (cortex: 2.57 ± 0.53 m/s, medulla: 2.87 ± 0.77 m/s, < 0.0001) and width (cortex: 2.99 ± 0.81 m/s, medulla: 3.24 ± 0.97 m/s, < 0.05) and that the spatial distribution and magnitude of SW velocity vary between these two anatomical planes. This work contributes to a larger body of literature assessing the mechanical properties of the ovary and related cells and specialized ECMs and will enable the rational design of biomimetic tissue engineered models and durable bioprostheses. Impact Statement Shear wave (SW) ultrasound elastography can be used to simultaneously assess the material properties and tissue structures when accompanied with B-mode ultrasound. We report a quantitative difference in mechanical properties, as inferred from SW velocity, between the cortex and medulla, with SW velocity being 11.4% and 8.4% higher in the medulla than the cortex when measured along the length and width, respectively. This investigation into the spatial and temporal variation in SW velocity in bovine ovaries will encourage and improve design of more biomimetic scaffolds for ovarian tissue engineering.
卵巢细胞外基质（ECM）的物理特性调节卵巢细胞的功能，特别是卵巢维持静息原始卵泡库的能力，同时允许一部分卵泡在动情周期中生长和成熟。长期循环人工卵巢的设计一直受到卵巢机械特性相关信息有限的阻碍。特别是，卵巢皮质和髓质这两个卵巢隔室的机械特性差异从未被量化过。剪切波（SW）超声弹性成像是一种成像方式，它可以根据 SW 的速度来评估材料特性，如机械特性，并结合 B 型超声进行内部解剖结构的可视化。我们使用 SW 超声弹性成像来评估整个牛卵巢。我们首次证明，在皮质和髓质之间，SW 速度推断出的机械特性存在差异，这是沿着长度（皮质：2.57±0.53 m/s，髓质：2.87±0.77 m/s，<0.0001）和宽度（皮质：2.99±0.81 m/s，髓质：3.24±0.97 m/s，<0.05）测量的。此外，SW 速度的空间分布和幅度在这两个解剖平面之间存在差异。这项工作为评估卵巢及其相关细胞和专门的 ECM 机械特性的大量文献做出了贡献，并将能够实现仿生组织工程模型和耐用生物假体的合理设计。 影响陈述 剪切波（SW）超声弹性成像是一种可以同时评估材料特性和组织结构的方法，当与 B 型超声结合使用时。我们报告了皮质和髓质之间机械特性的定量差异，SW 速度推断为 SW 速度，当沿着长度和宽度测量时，髓质分别比皮质高 11.4%和 8.4%。对牛卵巢中 SW 速度的空间和时间变化的研究将鼓励和改进用于卵巢组织工程的更仿生支架的设计。
