CHARATERISTICS OF DIFFERENT BIOREACTORS
Sheer Stress Mass Transfer Dimensionality Co-location of Dissimilar Cell Types Cell Density Static Culture System (T-Flasks) None Adequate 2D 3-4 layers 2D Limited 0.3-1x10^6 cells/ml Static Matrix Cultures None Limited 3D Limited 3D Limited Low Roller Bottles Medium Good 2D 3-4 layers 2D Very Limited 1-5x10^6 cells/ml Stirred Suspension Culture Medium/High Good Very Limited 3D Very Limited 10^6-10^7 cells/ml
Airlift Bioreactors Medium/Low Good Very Limited 3D Very Limited 10^6-10^8 cells/ml Hollow Fiber Perfused Systems None Good Limited 3D Limited 10^7-10^8 cells/ml RCCS Very Low Excellent Excellent 3D Excellent 10^7-10^8 cells/ml
The Rotary Cell Culture System (RCCS) from Synthecon is a new development in bioreactor technology which enables the cultivation of differentiated three dimensional cultures that mimic the structure and function of parental tissues.
Developed at the Johnson Space Center at NASA, the RCCS was originally designed to protect the delicate tissue cultures during space flight. However, it quickly became apparent that the unique environment provided by the RCCS of low shear force, high mass transfer and microgravity, enables three dimensional cell growth to take place in a conventional tissue culture incubator.
The RCCS has a wide range of cell and clinical, research applications including cancer research, "In Vitro" toxicology testing and tissue engineering.
Research and phase I clinical trials are already underway using the RCCS to investigate the growth and malignant changes of cancers as they develop from single cells to tumors including Melanoma, Prostate cancer, Breast cancer, Ovarian cancer, Osteosarcoma, Glioma, and Colon cancers. The RCCS model of three dimensional cell culture will enable the examination of gene expression as a function of the stage of tumor cell aggregate growth. This data may be useful in refining molecular-based approaches for the identification of genetic makers for patient prognosis, and in the design of specific molecular therapies.
Applications of Rotary Cell Culture
Polypeptides from Transformed Insect Cells
Undiscovered Proteins from Differentiated Cultures
IN VITRO TOXICOLOGY
Evidence suggests that the "configuration" of cell cultures influences their metabolic behavior towards different compounds, potentially masking or enhancing a pharmacologic or toxic effect. For example human hepatocytes grown as monolayer cultures metabolise the analgesic drug mofezolac at a significantly higher rate than cell suspension cultures. The differentiated three dimensional tissue produced in the RCCS provides a model which resembles the structure and function of parental tissue more closely than any other "In Vitro'''''''' culture system currently available.
CARTILAGE AND BONE TISSUE CULTURE
Considerable effort is being made to research methods for regenerating and repairing bone and cartilage. Several techniques, including bone implants and grafts are showing promise for providing a remedy for skeletal disorders and chondrodystrophies. The RCCS creates a culture environment conducive to cell aggregation, and provides a powerful new tool for the study of bone formation and chondronic mutations.
The RCCS provides a means to grow and expand hepatocyte culture into high fidelity models of liver tissue. This will have a number of important applications including the design of gene therapy protocols, hepatocyte transplantation, the development of extracorporal assist devices, and test systems for the design of hepatitis vaccines and testing of antiviral compounds.
THE PRINCIPLE OF CELL CULTURE
Most culture systems address one specific parameter e.g. shear force, at the expense of others i.e. mass transfer of nutrients and metabolic wastes, three dimensionality, and/or co-cultivation of dissimilar cell types. The RCCS is the first bioreactor designed to simultaneously integrate co-cultivation, low shear, high mass transfer, and three dimensional growth without sacrificing any other parameter.
The RCCS is a zero head space, aqueous medium filled bioreactor that suspends particles by rotating the vessel wall and integral gas diffusion membrane around the horizontal axis. This rotation can hold particles of up to 1 cm in diameter in orbital suspension, as the sedimentation forces induced by gravity are balanced by the centrifugal force generated by the rotation of the vessel.
Non-adherent cells may be cultured in suspension while adherent cells are grown on microcarriers. Long term cultures of weeks to several months can be maintained with appropriate media changes.
Cell Types Grown in the Rotary Cell Culture System
Normal Human Keratinocytes
Primary human embryonic kidney
Human breast cancer
Human prostate cancer
Human lung cancer
Human kidney cancer
Normal small intestine (epithelial & fibroblasts)
Human skin fibroblasts
Primary rat osteoblasts
Mouse osteoblast cell line
Rat salivary gland fibroblasts
Primary normal human hepatocytes
Primary mouse bone marrow stem cells
SP2 (mouse myeloma fusion partner)
L-1210 Leukemic cells of mice
Mouse hybridoma cell lines
Plant cells (tobacco callus)
Sf9 insect cells