Rice Grain Recombinant rHSA Powder Endotoxin Less Than 0.125 EU/Mg

Recombinant human albumin powder derived from plant

Human serum albumin (HSA) is the major protein component of human plasma with content of 42±3.5 g/L. HSA is synthelized in the liver and is mainly responsible for maintaining normal osmolarity in the blood circulation system, a carrier for numerous small molecules. The market demand for HSA is estimated at more than 500 tons per year worldwide. Currently, commercial production of HSA is primarily based on collected human plasma, which is limited in supply but of high pharmaceutical demand. Furthermore, there is an increasing public health concern with plasma-derived HSA (pHSA) with its potential risk for transmission of blood-derived infectious pathogens such as hepatitis and HIV virus.

Over the past decades, various expression systems have been used to produce rHSA, including Escherichia coli, Saccharomyces cerevisiae, Kluyveromyces lactis, Pichia pastoris, transgenic animals, and transgenic plants. Plant seeds, especially cereal crop seeds, are the promising bioreactors for producing recombinant proteins because they can achieve high level of recombinant protein, display outstanding protein stability, which could store for long periods with protein activity unchanged, and are well controlled on a commercial production scale.

Healthgen uses State-of-the-art platform called Oryz^HiExp, having high capacity to express proteins and peptides in the rice grain. The platform is a rice-specific endosperm cell-specific expression platform that focuses on the expression of animal-free products, safe recombinant proteins and peptides. Healthgen Biotech used this technique to express recombinant human albumin (OsrHSA) to achieve higher safety and biosafety. OsrHSA can be highly and stably expressed in rice seeds and can be processed cost-effectively. OsrHSA is determined to be equivalent to pHSA in terms of biochemical properties, physical structure, functions, biologic safety and immunogenicity.

Compared with other bioreactors, there are advantages of rice-specific endosperm cell-specific expression platform as bioreactor for molecular pharming:

• Rice seed has more biosafety than other species;
• Rice genome sequence database benefits to downstream processing design;
• Rice endosperm has high capacity to highly express recombinant proteins;
• Rice endosperm has capacity expressing complicated and functional proteins;