PurCell Bio is a new venture, building on research conducted at Montana State University by CEO Dr. Elizabeth Corbin. The research has yielded a non-toxic method of solubilizing lipids and other insoluble nutrients for media supplementation, and has returned data indicating that different cell types react very differently to different fatty acids and other hydrophobic nutrients. These nutrients are traditionally provided by supplementation with sera such as fetal bovine serum (FBS), other animal sourced sera or the carrier protein serum albumin. Use of serum has always been a “black box” approach to cell culture supplementation, providing a large and largely unknown amount and variety of fats, nutrients, hormones and biologically active molecules. Variability of sera by batch has always been recognized, and its deleterious effect on research results and cell-signaling efficiency has long been noted, but recently it has been discovered that both serum and serum albumin can carry toxins, drugs, prions and viral particles, which can contaminate entire cell lines. Testing to ensure these contaminants are not passed to users of resulting cells and cell based products is expensive at best. At worst, as in the case of prion contamination, there is no known test. This makes continued use of sera and serum albumins absolutely unacceptable for culture of cells used in applications intended for human use. Additionally, in light of current knowledge, it has been estimated that at least 15% of available banked cell lines are contaminated. It is clearly time to eliminate the use of animal based products like serum and serum albumin from cell culture, but alternatives produced thus far do not support cell growth and proliferation as well as serum alternatives. PurCell Bio has established a line of supplements, tailored for the needs of specific cell types, that produce equivalent, or better cell growth and proliferation results without animal derived components.
Through application of individual lipids to specific cell lines, PurCell Bio has developed chemically defined lipid supplement mixes that rival or even exceed cell proliferation results using FBS. Further development promises to produce a shelf stable solid that is soluble in aqueous media, and can replace serum, eliminating the variability and contamination issues associated with serum and serum albumin, and providing optimized, custom lipid/nutrient mixes for specific cell lines and applications, as well as individual complexed lipids for research. These supplements can be sold at a comparable price per liter to serum use, and do not require dry ice shipment or frozen storage.
Initial tests have returned promising results using four major cell types used in industry, and prototypes are being prepared for use in research. Proliferation of fibroblasts has been improved by 53% over FBS in side by side comparison. Supplement effects on muscle cells, a type used for production of “lab meat” has been established and supplement optimization is being set up. Human embryonic kidney cells (HEK), used in production of viral vectors, proteins, enzymes liposomes have been tested, and unique lipid effects are being analyzed for optimization. Addition of select lipids to cells during reprogramming to pluripotency has also returned excellent results, improving reprogramming efficiency by over 1200%, and increasing expression of pluripotency marker proteins. AmGen Inc, a major producer of therapeutic proteins, has expressed interest in PurCell Bio developing a supplement for their proprietary beta cell line, and researchers in Puerto Rico, Delaware and Texas, as well as Dr. Renee Reijo-Pera of Cal Poly await prototypes.
Partial automation of the complexation process is currently underway. This will eliminate transfer error, and ensure that supplement components are not exposed to contamination during production. This is currently being done by Dr. Corbin in the lab of Dr. Edward Dratz. Application of lipids and lipid mixes produced in this way will facilitate more accurate and precise analysis of effects on different cell types, and supplements will be optimized using Design of Experiments (DOE) computer generated experiments, and analyzed using DOE statistical software. This method will be used to optimize supplement mixtures for each cell type. Freeze dried prototypes can then be delivered to research institutions for application.
In an independent lab space, the production of nutrient kits for reprogramming of fibroblasts and blood cells to pluripotency (stem state) is also underway. These kits will consist of several supplements designed to support the stepwise process of reprogramming specific cell types to pluripotency. Once established and optimized, supplements will be applied to primary cells, eliminating the effects of prior serum supplementation on cells. Kits will then be marketed, initially to research institutions, and then to industry.
The market for serum and other reagents is over $1.3 billion annually. Reduction in numbers of healthy donors, contamination testing, and increases in cell based work have all created a growing market, with constraints that will continue to increase the price of using serum. “Serum free” alternative media are available, and some support cell growth almost as well as serum, but many of these contain serum albumin (Knock-Out Serum Replacement, $180/L), or are derived from human tissues (hPL, $195/L, requires anticoagulant addition), which potentially introduces contamination back into culture. Those few that do not contain any animal products either do not contain any lipids (Essential 8, $400/L; EX-Cell, $110/L requires addition of growth factors) contain commercial surfactants whose effects on cells are unknown (Chemically Defined Lipid Concentrate, $79/100mL use varies, only reduces the amount of serum required), and/or require additional supplementation with expensive growth factors that are also often animal derived (EX-Cell, Knock-out Serum Replacement, Chemically Defined Lipid Concentrate). All “serum free” media and supplements, once additional requirements are met, cost at least twice as much to use as serum. PurCell Bio can deliver superior results at comparable prices, with no exposure to contamination, facilitating the exciting cell based products and therapies of today and tomorrow.