PDMS Hydrophobic Surfaces for High-throughput Cancer Spheroid Culture

Hydrophobic surfaces have become popular for anti-biofouling applications (preventing bacteria adhesion) , but they can also be attractive platforms for non-adherent mammalian cell culture due to the low surface area in contact with the culture media. Suspension growth of cancer cells allows for the identification and subsequent enrichment of cancer stem cells (CSCs) by confirming their ability to form spheres in suspension, as it is known that only the CSC subset of the cancer cells can survive in suspension culture and form a sphere. Identification of CSCs is critical for effective cancer therapy research as they are a major source of metastasis and therapeutic resistance in vivo.

Cancer stem cells (CSCs) are rare and difficult to isolate. Culture from single cells in suspension, however, enriches the population as only CSCs survive and self renew as spheroids.

Hydrophobic PDMS surfaces show the ability to encourage CSC sphere formation.

Integrating PDMS hydrophobic surfaces into single cell capture microfluidic devices allows for high thoughput single cell capture (>90%) and long-term cell viability for CSC enrichment by cancer spheroid culture from single cells

We report successful non-adherent spheroid culture of cancer cells on hydrophobic surfaces, formed in polydimethylsiloxane (PDMS), and its extension to high-throughput culture within an integrated microfluidic device. The surface hydrophobicity was characterized by observing the contact angle of deionized water droplets. Various cell types were grown on the hydrophobic designs (circular, triangular, square, and honeycomb), but only the honeycomb hydrophobic design was capable of maintaining hydrophobicity to prevent cell adhesion. With the honeycomb hydrophobic surface, cancer spheroids were grown in suspension starting from single cancer stem cells both in macro-scale wells and in integrated microfluidic microwells.

Related Publication
  1. P. Ingram, M. Im, S. McDermott, M. Wicha, and E. Yoon. "Spheroid Cell Culture on PDMS Hydrophobic Surfaces and Integration into Microfluidic Devices," International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS '11), 2011, pp. 1539-1541.