Toward the commercialization of recombinant pharmaceuticals expressed in plants

Recent developments have shown that the production of recombinant proteins in plants is more useful than in microbial, insect, or mammalian cell-based expression systems in terms of cost-effectiveness, scalability, safety, and sustainability. Furthermore, transient expression systems in plants may be superior to stable transgenic plants in terms of cost, yield, environmental impact, and regulation compliance. Recombinant proteins, such as enzymes, growth factors, scaffolds, and antibodies are in high demand for use in the food and chemical industries, and will be in even greater demand for diagnostic, therapeutic, and pharmaceutical applications that require high-quality proteins. In this review, we summarize the comparison of recombinant protein expression strategies in mammalian cells, microorganisms, insects, and plants. Furthermore, the efficacy of protein expression in plant cultivation environments, the optimal protein extraction, purification methods, and costs and risks are discussed. We should be aware that the production of recombinant proteins has not only scientific challenges, but also economic and political issues that must be overcome.