In this study, the medium was changed manually through the vascular channels 3-4 times/day. The new culture medium was injected into one end of vascular channels, and the old medium was collected from the other end. This process was repeated 3-5 times to completely replace the old medium sitting on the vascular channels with the new medium.

Our platform is capable of imaging through the plexiglass with dynamic culture flow, as described in previous studies (1-4). Ismatec peristaltic pump was used to create perfusion for dynamic culture conditions.

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2. V. K. Lee, D. Y. Kim, H. Ngo, Y. Lee, L. Seo, S.-S. Yoo, P. A. Vincent, G. Dai, Creating perfused functional vascular channels using 3D bio-printing technology. Biomaterials 35, 8092–8102 (2014).

3. M. S. Ozturk, V. K. Lee, L. Zhao, G. Dai, X. Intes, Mesoscopic fluorescence molecular tomography of reporter genes in bioprinted thick tissue. J. Biomed. Opt. 18, 100501 (2013).

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