Tumor-on-Chip: Simulation of Complex Transport Around Tumor

Nanoparticles (NP) offer great potential as drug carriers for targeted delivery to tumor by increasing the delivery efficacy and reducing non-specific accumulation at non-targeted sites [1]. Despite these promising early outcomes [2], the NP delivery to target tumor site is still significantly limited due to complex in vivo transport barriers [3–5]. In order to improve the in vivo delivery efficacy, the NPs should be designed considering all these complex transport barriers beyond currently used enhanced permeation and retention (EPR) effect [6]. However, testing of NP delivery are primarily based on simple 2D or 3D in vitro cell cultures or animal models. However, these static 2D or 3D tumor models oversimplify the actual in vivo tumor environment including the absence of tissue-tissue interactions such as blood-endothelium, endothelium-intersititum, high interstitial fluid pressure, and interstitium-lymphatics [2, 3]. The animal models can provide the testbed with these tissue-tissue interactions, but it is very difficult to establish quantitative understanding of the NP transport at these tissue-tissue interfaces. To address these challenges and bridge the in vitro static models with the animal models, here we developed a 3D multi-layered microfluidic system that mimics the tissue-tissue interactions at tumor microenvironment is developed. The system is then used to investigate the transvascular and interstitial transport of NPs in tumor.