Supplementary MaterialsSupplemental Statistics and Methods 41598_2018_21075_MOESM1_ESM. cell viability, viable tumor area and associated endothelial cytotoxicity. Overall, the developed microfluidic tumor-mimetic platform facilitates investigation of cancer-stromal-endothelial interactions and highlights the role of a fluidic, tumor-mimetic vascular network on anti-cancer drug delivery and efficacy for improved translation towards pre-clinical studies. Introduction Malignancy cell invasion, migration, intravasation and extravasation are Rabbit Polyclonal to OR2G2 key events, amongst others, in driving the complex phenomena of tumor malignancy and metastasis1,2. The synergistic interplay between cancer cells and surrounding stromal components (including cancer-associated fibroblasts, endothelial cells, and extracellular matrix (ECM) proteins) influences the overall course of disease progression and response to anti-cancer therapeutics2,3. Recapitulation of the complex and heterogeneous tumor microenvironment (TME) with a high degree of physiological relevancy in systems is usually a significant problem, which has resulted in the introduction of many biomimetic three-dimensional (3D) versions that can catch key areas of the tumor milieu for investigations in tumor research4C6. Recent advancements in biofabrication methods have enabled the usage of organ-on-a-chip systems for recapitulating the complexities from the individual physiology7C9; these HG-10-102-01 micro-scale systems decrease price considerably, labor and period in comparison to versions while offering essential still, contextual information for even more translation in pre-clinical research. Within this framework, microfluidic cancer-on-a-chip systems have also surfaced as a very important device for the analysis of malignant and metastatic procedures within the TME as well as for evaluation of efficacies of anti-cancer therapeutics10C15. Bioengineered 3D tumor versions developed till time incorporate varying degrees of pathological complexity with respect to that found in native tumors. The incorporation of stromal fibroblasts and supporting cell types within ECM-mimic matrices and scaffolds lends additional physiological context to these malignancy models4,6. Co-culture of stromal fibroblasts and supporting cell types with malignancy cells in 3D microenvironments allow for investigation of vital intercellular interactions and bidirectional signaling mechanisms involved in tumor progression and malignancy4,6. In addition, the presence of specific topographical, physical, mechanical and biochemical cues in the stromal ECM also influence 3D malignant behavior16,17. However, the majority of cancer-on-a-chip platforms are highly reductionist and comparatively simplistic in relation to native, vascularized tumors and designed to study specific events of tumor progression (including extravasation, angiogenesis, bidirectional cell-cell signaling) rather than facilitate holistic interrogation of malignancy as an organ with its surrounding interactive microenvironment15,18. Although it is known that uniform delivery of chemotherapeutics in native tumors is usually impeded by the disorganized, leaky and abnormal tumor vasculature, microfluidic systems and current models have yet to exploit and investigate the role of these irregular vascular features in the transport processes. In addition, the impact of on-chip tumor microvascular architecture and circulation patterns around the delivery, penetration and uptake of anti-cancer therapeutics into the central tumor tissue is usually yet to be explored. The use of biomaterial-based scaffolds and matrices in the development of 3D malignancy models has facilitated the recapitulation of tumor ECM and its mutual crosstalk with malignancy cells and supporting stromal cell-types19. Some common ECM-mimetic biomaterials include collagen, Matrigel, alginate, silk fibroin and peptide-conjugated poly(ethylene glycol) HG-10-102-01 (PEG)-based hydrogels, amongst others20,21. In this study, we explore the use of PEG-fibrinogen (PF), a previously underutilized biomaterial in malignancy studies, for investigation of 3D cancer-ECM and cancer-endothelial interactions. PF, obtained by the covalent coupling of poly(ethylene glycol diacrylate) (PEGDA) and fibrinogen, is usually readily photocrosslinkable in the presence of Eosin Y under visible light to yield biocompatible hydrogels and has been previously used for a number of applications including cardiogenic differentiation of human induced pluripotent stem cells (hiPSCs)22, chondrogenic differentiation of human bone marrow derived mesenchymal stem cells HG-10-102-01 (hBM-MSCs)23 and investigation of cellular morphogenesis of human fibroblasts24. Hence, incorporation of fibrinogen in the stromal matrix of bioengineered 3D malignancy models provides a unique opportunity to explore cancer-ECM interactions, 3D malignancy cell behavior.