Droplet-based microfluidic system for multicellular tumor spheroid formation and anticancer drug testing

Abstract

Creating multicellular tumor spheroids is critical for characterizing anticancer treatments since it may provide a better model than monolayer culture of tumor cells. Moreover, continuous dynamic perfusion allows the establishment of long term cell culture and subsequent multicellular spheroid formation. A droplet-based microfluidic system was used to form alginate beads with entrapped breast tumor cells. After gelation, the alginate beads were trapped in microsieve structures for cell culture in a continuous perfusion system. The alginate environment permitted cell proliferation and the formation of multicellular spheroids was observed. The dose-dependent response of the tumor spheroids to doxorubicin, and anticancer drug, showed multicellular resistance compared to conventional monolayer culture. The microsieve structures maintain constant location of each bead in the same position throughout the device seeding process, cell proliferation and spheroid formation, treatment with drug, and imaging, permitting temporal and spatial tracking.

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].…”

“…In an interesting work, Sabhachandani et al [63] used alginate as a hydrogel to encapsulate breast cancer cells (MCF-7) and fibroblast cells to form co-cultured spheroids in a microfluidic device. Alginate hydrogel permits facile de-crosslinking with the aid of calcium chelator, therefore, the spheroids can be retrieved for subsequent culture and assays [64].…”

Encapsulation of single cells into monodisperse droplets by fluorescence-activated droplet formation on a microfluidic chip

“…In addition to compartmentalizing reactions, droplet-based microfluidics can also be used to encapsulate prokaryotic [14][15][16][17][18] and eukaryotic cells [19][20][21][22][23], and even the embryos of multicellular organisms [24,25], which opens up a new avenue for cell analysis. Recently, Brouzes et al [19] developed a droplet-based viability assay that permitted quantitative analysis of cell viability and growth within compartmentalized aqueous droplets.…”

Microfluidics platform for measurement of volume changes in immobilized intestinal enteroids

“…[16][17][18][19][20] However, to date it has not been possible to form intestinal enteroids, which consist of a single layer of cells surrounding a central lumen, by trapping cells in microchannels. Culture of intestinal enteroids involves propagation of single stem cells supported in a matrix or hanging from a drop.…”