Expansion Of Porcine SK-RST Cells On Hillex® II Microcarriers Via Serial Passage In Stirred Vessels

Manufacturing processes used for production of vaccines, biologics and cell therapeutics routinely employ two-dimensional (2-D) culture systems such as roller bottles or cell cubes/factories for expansion of cells to seed large bioreactors. These formats occupy a large footprint, are labor intensive, and are susceptible to frequent contamination due to many open handling steps. Closed-impeller bioreactors provide logical alternatives to 2-D culture systems. Advantages of bioreactors include the ability to precisely control and optimize cell growth conditions, ease of use, and avoidance of contamination due to the "closed" nature of the system. Additionally, the recent emergence of disposable bioreactor technology eliminates the need for cleaning validation.

Microcarriers provide a large surface area for growth of adherent cell types and thus facilitate the use of bioreactors for attachment-dependent cell-based manufacturing. Because each cell type has its own requirements for attachment and growth, the optimal microcarrier and media conditions should be selected experimentally.

Porcine SK-RST kidney epithelial cells are commonly used for diagnostic testing of swine diseases and for production of veterinary and human pharmaceuticals. They offer the advantage of being free of endogenous porcine viruses and exhibit a cytopathic effect when infected with multiple viruses. In this study demonstrate that Hillex® II microcarriers provide an ideal substrate for expansion of Porcine SK-RST cells in closed stirred vessels and lay the groundwork for subsequent developmental studies in larger bioreactor formats.

Results presented here demonstrate the feasibility of using Hillex® II microcarriers for expansion of porcine SK-RST cells via microcarrier-based serial passage in stirred vessels. The data indicated that subsequent passage to different microcarrier types after serial passage is also achievable.