Structural color heart-on-a-chip for evaluating the myocardial protection effects of traditional Chinese medicine

Many Chinese medicines have shown protective effects on the heart, while their specific effects and modes of action are still lacking of intuitive studies. In this paper, we propose a structural color heart-on-a-chip from layer assembly for evaluating the myocardial protection effects of traditional Chinese medicine. The structural color scaffolds are imparted with a striped microstructure on one side for inducing the alignment of cardiomyocytes, and an inverse opal nanostructure on the other side for optical sensing. Because the scaffold could generate obvious color changes upon cardiomyocyte contraction, its integration into a microfluidic chip provides a simple screening platform to study the pre-protective effects of Chinese medicine against cardiac injury. We have demonstrated that with the induction of doxorubicin, the injured cardiomyocytes presented abnormal morphology, disappeared sarcomere and depressed beating behaviors that could be reflected by reduced structural color changes. On the contrary, traditional Chinese medicine pre-protection can increase the vitality of cardiomyocytes, reduce reactive oxygen species production, and improve the contractile function of cardiomyocytes, which is highly consistent with the known conclusion. These results indicated that our structural color heart-on-a-chip with real-time visualization characteristics could provide an ideal platform for traditional Chinese medicine development and drug screening.