Nanoencapsulation has proven to be an efficient route to increase significantly the solubility and bioavailability of organic compounds. This aspect of nanotechnology is illustrated for the case of phthalimide-lactone (PL), a recently synthesized strigolactone mimic whose very limited solubility in water, as a free chemical, precludes its practical use as an agrochemical in the fight against parasitic plants. Pluronic F-127 (P127) nanoparticles functionalized with PL have been synthesized and embedded in a polymeric matrix of poly(vinyl alcohol) (PVA). Low-voltage and medium voltage imaging and spectroscopic scanning electron microscopy (S(T)EM) techniques were combined to confirm the synthesis of multicore nanoparticles that were rich in nitrogen, a finding that is due to the successful encapsulation of PL. This PL@P127/PVA nanobiostimulator formulation has an impressive solubility in water, that is, 27 times higher than that of pure phthalimide-lactone. Also critical from the functional point of view, comparative bioassays clearly showed that the intrinsic stimulatory activity of this agrochemical is fully maintained in the nanoencapsulated formulation.
Keywords: electron microscopy; honeypot strategy; nanostimulator; organic nanoparticle; parasitic plant.