Human serum albumin (HSA) is an important supplement in cell culture medium. Thanks to HSA ability to carry and to deliver important nutrients to cells, it increase the viscosity of the medium, provide a mechanical protection for cells. Moreover, HSA binds toxins thus avoiding toxic effects, binds excessive proteins acting as a buffer.
In recent years, there has been an increased demand for animal-free components to replace serum or animal originated supplements to eliminate the risk of viruses and mycoplasma contaminants. Using the rice endosperm specific expression platform, the recombinant human serum albumin (OsrHSA), which is animal component free, can provide an economical and safe approach for the production of non–animal-derived compounds, which will facilitate development of products from cell cultures.
The immunofluorescent staining showed OsrHSA was effective in keeping undifferentiation and keeping viability of iPS cells.
OsrHSA was used in PBMC culture to induce the CIK cells. After 14 days, the total cell amount reach to 6.6X109, and the CD3+CD56+ rate is more than 22.97%. It showed that OsrHSA had effective action in promoting CIK cell growth.
Human plasma is also in limited supply. Rice as bioreactor show great promise as a flexible system for the production and processing of OsrHSA with intact biochemical features on a large scale. The rice endosperm specific expression platform is easy to be large-scale, because the rice endosperm has the protein body, which can keeps proteins stability and bioactivity. At present, the production capacity of OsrHSA is almost 1000 kg / year.