Abstract：
3D culture of ovarian follicles in hydrogel matrices is an important emerging tool for basic scientific studies as well as clinical applications such as fertility preservation. For optimizing and scaling 3D culture of preantral follicles, there is a need for identifying biomaterial matrices that simplifies and improves the current culture procedures. At present, microencapsulation of follicles in alginate beads is the most commonly used approach. However, this technique involves notable manual handling and is best suited for encapsulation of single or several follicles. As a potential alternative, we here explore the suitability of different particle-based hydrogel matrices, where follicles can easily be introduced in tunable 3D environments, in large numbers. Specifically, we study the growth of secondary murine follicles in microgranular alginate and nanofibrillar cellulose matrices, with and without cell-binding cues, and map follicle growth against the viscoelastic properties of the matrices. We cultured follicles within the particle-based hydrogels for 10 days and continuously monitored their size, survival, and tendency to extrude oocytes. Interestingly, we observed that the diameter of the growing follicles increased significantly in the particle-based matrices, as compared to state-of-the-art alginate micro-encapsulation. On the other hand, the follicles displayed an increased tendency for early oocyte extrusion in the granular matrices, leading to a notable reduction in the number of intact follicles. We propose that this may be caused by impaired diffusion of nutrients and oxygen through thicker matrices, attributable to our experimental setup. Still, our findings suggest that viscoelastic, granular hydrogels represent promising matrices for 3D culture of early-stage ovarian follicles. In particular, these materials may easily be implemented in advanced culturing devices such as micro-perfusion systems.
摘要：
在水凝胶基质中进行卵泡的3D培养是基础科学研究以及临床应用（例如生育力保存）的重要新兴工具。为了优化和扩展腔前卵泡的3D培养，需要鉴定简化和改进当前培养程序的生物材料基质。目前,在藻酸盐微珠中微囊化毛囊是最常用的方法。然而,该技术涉及值得注意的手动处理，最适合单个或多个毛囊的封装。作为一种潜在的选择,我们在这里探索不同的基于颗粒的水凝胶基质的适用性，毛囊可以很容易地在可调的3D环境中引入，大量。具体来说,我们研究了微粒藻酸盐和纳米纤维纤维素基质中次级鼠卵泡的生长，有和没有细胞结合线索，并根据基质的粘弹性特性绘制卵泡生长图。我们在基于颗粒的水凝胶中培养卵泡10天，并连续监测其大小，生存,并倾向于挤出卵母细胞。有趣的是,我们观察到，在基于颗粒的基质中，正在生长的卵泡的直径显着增加，与最先进的藻酸盐微囊化相比。另一方面,卵泡在颗粒基质中显示出早期卵母细胞挤出的增加趋势，导致完整卵泡数量显着减少。我们认为这可能是由于营养物质和氧气通过较厚的基质扩散受损引起的，归因于我们的实验设置。尽管如此，我们的发现表明粘弹性，颗粒水凝胶代表了早期卵泡3D培养的有希望的基质。特别是,这些材料可以容易地在先进的培养装置如微灌注系统中实施。
