The tumor microenvironment strongly effects the drug response. Although the advantages of organotypic 3D-cell-culture models are known for years, complex production and readout processes impede the implementation in an industrial setting. This study, presents for the first time a novel multi-well platform in a standard 96-well format to produce organotypic, scaffold-free cancer microtissues models and its implementation in an automated screening process. This technology allows to produce either homotypic or heterotypic tumor microtissues in a hanging-drop culture by liquid top-loading similar to standard 96-well plates. The core piece of the well is a microfluidic channel connecting an inlet funnel at the top and an outlet funnel at the bottom of the plate, where a hanging drop is formed and stabilized by a combination of capillary and surface-tension forces. The use of this technology enables the automated production of microtissues with a very narrow size distribution below 10% on plate and batch-to-batch.

3 cancer microtissue models were developed from two colon cancer and one breast cancer cell lines and characterized in terms of their proliferative capacity and growth characteristics. Process parameters for media exchange, addition of compounds, microtissue-size variances and implementation of cell-based viability assays (ATP, LDH and size) were established. As a proof of concept, a whole screening process using four reference compounds was performed in comparison to classical monolayer cultures underlining the different behavior of both cell-culture models. Finally, four novel compounds that inhibit tumor cell proliferation in monolayer cultures, were tested for their potential in a 3-D system.

Overall, we could demonstrate that organotypic microtissues can be implemented into an automated screening process using standard liquid-handling robotics. The use of this system in drug development may strengthen the predictive force of the in-vitro evaluation of novel drug candidates and reduce drug failure in clinics.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4274. doi:10.1158/1538-7445.AM2011-4274