Drug testing and flow cytometry analysis on a large number of uniform sized tumor spheroids using a microfluidic device

Abstract

Three-dimensional (3D) tumor spheroid possesses great potential as an in vitro model to improve predictive capacity for pre-clinical drug testing. In this paper, we combine advantages of flow cytometry and microfluidics to perform drug testing and analysis on a large number (5000) of uniform sized tumor spheroids. The spheroids are formed, cultured, and treated with drugs inside a microfluidic device. The spheroids can then be harvested from the device without tedious operation. Due to the ample cell numbers, the spheroids can be dissociated into single cells for flow cytometry analysis. Flow cytometry provides statistical information in single cell resolution that makes it feasible to better investigate drug functions on the cells in more in vivo-like 3D formation. In the experiments, human hepatocellular carcinoma cells (HepG2) are exploited to form tumor spheroids within the microfluidic device, and three anti-cancer drugs: Cisplatin, Resveratrol, and Tirapazamine (TPZ), and their combinations are tested on the tumor spheroids with two different sizes. The experimental results suggest the cell culture format (2D monolayer vs. 3D spheroid) and spheroid size play critical roles in drug responses, and also demonstrate the advantages of bridging the two techniques in pharmaceutical drug screening applications.

Drug delivery to solid tumors: the predictive value of the multicellular tumor spheroid model for nanomedicine screening

“…19,23 Recently, innovative but sophisticated solutions have taken advantage of new technologies, such as microfluidics, to improve the control of size and composition of MCTS while maintaining high throughput (Table 1). 19,36 To be more representative of tumor complexity, coculture of tumor cells with immune, endothelial cells or fibroblasts helps to better understand a crosstalk between cancer and stromal cells as well as the mechanisms of metastatic invasiveness. 19,33,37 For example, the migration of endothelial cells into MCTS or the formation of vascular networks within spheroids is often used to assess the potential of tumor vascularization.…”

“…19,40,41 Moreover, the development of MCTS-based biosensor devices is becoming widespread. 36,42 Recently, Patra et al demonstrated the advantage to couple microfluidics with flow cytometry for the rapid production and viability analysis of a great number of MCTS with well-defined size, which were submitted to different drugs and their combination. 36 Drug screening typically involves several steps.…”

Inventions and Innovations in Preclinical Platforms for Cancer Research

“…Microwells [8,25,[87][88][89] and U-shaped microstructures [21,64,[90][91][92][93] have been designed for spheroid formation and culture in microfluidic platforms. These structures facilitate short-term [23,94], controllable and uniform diameter [22,95] and compact spheroid generation [32,92].…”

“…Few minutes are needed that cells deposit on the bottom of the microwells and the microchannel ( Figure 4B). The cells that did not trap in the microwells are pushed out of the chip before the cells make aggregations and clog microchannels [8,24,103] (Figure 4C). Next, the cells begin aggregation and form spheroids ( Figure 4D) and are culture for drug screening ( Figure 4E).…”

“…This feature is the most significant feature of the tumour environment which dominantly modifies the outcome of the chemotherapy, photodynamic therapy and so forth on the cancer cells [7][8][9]. There are a few microfluidic platforms for modelling the angiogenesis, cancer cell migration and metastasis which are not the main purpose of this review [10,11].…”