细胞相容性试验

有没有大佬解释一下，为什么细胞相容性试验大多数用癌细胞，而不使用正常细胞呢？

如：Cell viability

HPG showed very good biocompatibility according to the previous report (Kainthan, Janzen, Levin, Devine, & Brooks, 2006) and the toxicity of CDs was dependent on the route of administration, the cavity size (a-, β- or y-CD), and chemical modification (hydroxypropyl-CD, sulfobutylether-CD, CD sulfate and methylated CD) (Zhang et al., 2009). Therefore, it was important in the present study to verify the innocuous nature of the polymerized B-CD on the surface of HPG in order to prevent the deactivation of the encapsulated insulin.Fig. 3 shows the results of cytotoxicity measurements of the samples analyzed by the MTT method in Caco-2 cell line. As shown in Fig. 3A, there was no toxic effect of all HPG-g-CD NPs up to a concentration of 200 μg/mL (cell viability above 100%) after incubating for 48 h. This might be attributed to the reduction of the density of amino groups by the introduction of β-CD to HPG-g-CDs. Davis et al. reported that the introduction of cyclodextrin lowered the toxicity of polyether-imide (PEI) by decreasing the density of amino groups. In addition, the large cyclodextrin molecules can sterically reduce nonspecific binding affinities (Pun et al., 2008). From Fig. 3B, we could see that the cell viability of Caco-2 cells was maintained over 100% for 96h and no toxicity was shown with an increase