6.4.8　Biocompatibility

Since polymer nano-drug carriers are distributed in both healthy tissues and organs，their biocompatibility is important to achieve a good therapeutic effect.Biocompatibility in pre-clinical trials mainly includes two aspects：in vitro and in vivo.For in vitro biocompatibility，the polymer nano-drug carriers can be incubated with normal cells，and the effect of carrier system on the proliferation of normal cells can be evaluated by the thiazole blue（MTT）method.After confirming that the polymer nano-drug carrier has a good in vitro biocompatibility，we will evaluate the in vivo biocompatibility by detecting its effect on the heart，liver，kidney，and other important organs.These organs were then extracted to prepare paraffin sections，stained with hematoxylin and eosin and observed on an optical microscope to check whether the polymer nano-drug carriers would cause pathological changes in the organs.In addition，the biomarkers of the heart，liver，kidney，and other organs were detected to further determine the biocompatibility of nano-drug.Only the polymer nano-drug carriers that exhibit considerable biocompatibility both in vitro and in vivo may be further evaluated in clinical trials.(https://www.daowen.com)