(496g) Nanoharvesting of Therapeutics from Living Plant Cultures By Engineered Mesoporous Silica Nanoparticles
Here, nanoharvesting of polyphenolic flavonoids, a model class of plant produced therapeutics, enriched in genetically modified S. nemoralis hairy root cultures, is performed using mesoporous silica nanoparticles (MSNPs) functionalized with both amines and titanium dioxide (TiO2). Amine functionalization was performed to facilitate uptake of nanoparticles into plant cells, and TiO2 functionalization to provide coordination binding sites for metabolites. MSNPs (165 nm diameter) with highly porous structures were synthesized and functionalized with amines and TiO2. Particles were shown to be taken up in S. nemoralis hairy roots, and recovered using external centrifugal forces. Intracellular uptake and localization of the nanoparticles (0-1000 µg/ml in Murashige and Skoog media) in hairy roots were visualized by fluorescent imaging, after tagging the nanoparticles with rhodamine B isothiocyanate (RITC). Quenching of fluorescence in bulk solution using trypan blue was used to confirm intracellular localization of the tagged particles. Post-uptake viability and flavonoid reproduction potential of hairy roots was demonstrated by a concentration and functionalization dependent growth study. Proof of the flavonoid nanoharvesting was demonstrated from increased antiradical activity against 2, 2-diphenyl-1-picrylhydrazyl and displacement of specific ligand [3H]-methyllycaconitine by centrifugally recovered particles. Quantification of the TiO2 functionalized and fluorescent tagged nanoparticle uptake and recovery mechanisms after uptake will be reported by analyzing TiO2 content of the particle exposed roots and the fluorescence intensity of recovered solution, respectively. This application of engineered mesoporous silica nanoparticles is broadly applicable as advanced separation process for the broad classes of biomolecules from living and functioning plant cultures.