The use of animal models has been a vital part of research in many scientific studies. Animal models are able to give ‘in vivo’ data, which is truer to life than that which laboratory conditions (in vitro) would give as they provide researchers with a better understanding of the complexity of biological processes taking place in situ. However, the use of animal models in research brings up important ethical issues and usually increases costs and study time.
The technique of two-dimensional cell culture has provided an easy and efficient way of studying human tissue cultures, parasites and pathogens in the laboratory. However, a problem with this kind of culturing is that the cells are in contact with an artificial surface and adopta planar shape on the plate, which can affect important aspects of the biology of the cells. In contrast,三维细胞culture could provide a microenvironment that is more natural and enable cell architecture to resemble the in vivo situation.
将水凝胶用于3-D培养
水凝胶是亲水性的天然或合成聚合物链网络。它们可以吸收大量的水，从而使它们非常灵活，因此它们在尿布等产品中使用。水凝胶能够将细胞保持在三维结构的情况下，而不会影响其形态，并且可以在需要时弥补。它们是快速的设置，易于处置且相对便宜，可能使水凝胶成为培养细胞的选择，而不是使用动物模型。
英国基尔大学的研究人员开始研究水凝胶用于体外培养利什曼尼亚，一种感染人类的单细胞寄生虫。
利什曼尼亚寄生虫
利什曼病is a vector-borne tropical disease caused by protozoa of the利什曼尼亚genus. It is spread through thefemale sandfly（Phlebotominea）矢量。
My summer project
在2017年夏季，我开始研究水凝胶的形成，并在基尔大学的应用昆虫学和寄生虫学中心培养THP-1巨噬细胞。我发现用作形成水凝胶的主要成分的胶原蛋白构建体适合这些细胞系的培养。但是，我发现巨噬细胞系在形成过程中需要在凝胶中预混合。对文献的研究表明，用于刺激细胞的分化的PMA（佛波尔12-羟基含量13-乙酸盐），当将细胞系和PMA放置在已经形成的凝胶的顶部以进行胶原蛋白的结构时，影响了形成的凝胶的胶原蛋白结构。an ‘invasion’ analysis.
I also discovered that high-resolution imaging equipment must be used for imaging of the gels, as an epifluorescence microscope was unable to give clear images of the cells within the gel. Blurry and dull images were caused by light being scattered by the collagen fibers before reaching the eyepiece of the microscope. Techniques such as confocal, or multiphoton microscopy are therefore required for future work.
研究人员希望能够证明水凝胶可用于涉及寄生虫的研究利什曼尼亚by culturing macrophages in this 3-D system, then infecting the cells with the parasite. It is unknown whether there will be a difference in anti-parasitic drug effects, or cell infection rates when 2D or 3D cultures are used. However, work is now being carried out to find the effects of culturing cells and parasites in hydrogels, and comparing the results to 2-D plate cultures.
If there is an improvement in growth rates, drug interactions or cell-parasite interactions, it may be possible for hydrogels to be used as an alternative to both conventional culture systems and animal model studies. Hydrogels are now routinely used to culture other eukaryotic cell types and we may be able to adopt procedures from other research areas. Multiple types of hydrogels can be made, including polystyrene and gelatine as these scaffolds are also able to hold cells in three dimensions. This emerging technique will undoubtedly return some interesting results for the culture of利什曼尼亚- 感染的巨噬细胞，并且可能能够在不使用动物的情况下复制“体内”疾病，使研究人员能够模仿寄生虫感染并研究更有效的治疗方法。
注释