Gene delivery strategies for therapeutic proteins production in plants: Emerging opportunities and challenges

There are sharply rising demands for pharmaceutical proteins, however shortcomings associated with traditional protein production methods are obvious. Genetic engineering of plant cells has gained importance as a new strategy for protein production. But most current genetic manipulation techniques for plant components, such as gene gun bombardment and Agrobacterium mediated transformation are associated with irreversible tissue damage, species-range limitation, high risk of integrating foreign DNAs into the host genome, and complicated handling procedures. Thus, there is urgent expectation for innovative gene delivery strategies with higher efficiency, fewer side effect, and more practice convenience. Materials based nanovectors have established themselves as novel vehicles for gene delivery to plant cells due to their large specific surface areas, adjustable particle sizes, cationic surface potentials, and modifiability. In this review, multiple techniques employed for plant cell-based genetic engineering and the applications of nanovectors are reviewed. Moreover, different strategies associated with the fusion of nanotechnology and physical techniques are outlined, which immensely augment delivery efficiency and protein yields. Finally, approaches that may overcome the associated challenges of these strategies to optimize plant bioreactors for protein production are discussed.