Molecular farming on rescue of pharma industry for next generations

Recombinant proteins expressed in plants have been emerged as a novel branch of the biopharmaceutical industry, offering practical and safety advantages over traditional approaches. Cultivable in various platforms (i.e. open field, greenhouses or bioreactors), plants hold great potential to produce different types of therapeutic proteins with reduced risks of contamination with human and animal pathogens. To maximize the yield and quality of plant-made pharmaceuticals, crucial factors should be taken into account, including host plants, expression cassettes, subcellular localization, post-translational modifications, and protein extraction and purification methods. DNA technology and genetic transformation methods have also contributed to great parts with substantial improvements. To play their proper function and stability, proteins require multiple post-translational modifications such as glycosylation. Intensive glycoengineering research has been performed to reduce the immunogenicity of recombinant proteins produced in plants. Important strategies have also been developed to minimize the proteolysis effects and enhance protein accumulation. With growing human population and new epidemic threats, the need for new medications will be paramount so that the traditional pharmaceutical industry will not be alone to answer medication demands for upcoming generations. Here, we review several aspects of plant molecular pharming and outline some important challenges that hamper these ambitious biotechnological developments.