Transgenic Plants as Factories for Biopharmaceuticals
Cultured mammalian cells, bacteria and fungi provided excellent production systems in the past for the production of biopharmaceuticals. However, with cultured mammalian cells are also sensitive to shear forces occurring during industrial-scale culture and also to the variation in temperature, pH, dissolved oxygen and certain metabolities. This makes it necessary to control culture conditions thus adding to the cost. However, the bacterial and fungal systems are more robust, but they are not ideal for synthesis of many mammalian proteins, due to differences in metabolic pathways, protein processing, codon usage and the formation of inclusion bodies.

Like edible vaccines, the biopharmaceuticals derived from transgenic plants can be stored and distributed as seeds, tubers and fruits, which can be either directly used for oral ingestion or for extraction of the biopharma­ceutical. This will make the immunization programmes in the developing countries cheaper and easy to administer, since the delivery by direct ingestion of modified plant product eliminates the need for product purification, which is an expensive process in pharma­ceutical industry. Other advantages of using transgenic plants as production systems for the production of biopharmaceuticals include (i) comparatively higher yields at a relatively low cost (according to some estimates, the production of a recombinant protein in provided excellent production systems in the past transgenic plants can be 10 to 50-fold cheaper than producing the same protein by E. coli)  (ii) reduced health risk, which is common in the coventional pharmaceuticals (iii) relatively little capital investment, due to the existing infrastructure.