Insights into the floral senescence effects of nanoparticles

Abstract

Flowers could be valuable addenda to nanomedicine labs as in vivo models crossing the gap between the cell culture and small mammals. However, as it is shown here, floral models continue to be predominantly utilized within resource-limited research environments and remain largely underrepresented in mainstream biomedical investigations conducted by well-funded institutions in the developed world. The ability to delay the senescence of Orange Jubilee wildflowers was tested here on three types of nanoparticles: selenite-doped hydroxyapatite (HAp), citrate-stabilized HAp, and superparamagnetic iron oxide. Integration of selenite into the HAp crystal lattice produced a mild increase in the senescence rate relative to HAp. Iron oxide nanoparticles produced nil effects on senescence when added as powders and marginal effects when delivered as colloids. Colloidal stabilization of HAp nanoparticles with citrates significantly extended the flower viability, which was due to the ability of citrates to: (i) disperse the nanoparticles and thus facilitate their penetration into herbal tissues via their upward transfer along the xylem, and (ii) impart moderate acidity to the medium and thus intrinsically inhibit the growth of bacteria that block the flower stem and obstruct the water uptake. Orange Jubilee flowers prove as a solid, albeit pleiotropic model for assessing the biological barrier permeation and antibacterial activity of colloids and fine powders. Quests for similar in vivo models may result in less ambiguous and more effective models for the preclinical assessment of nanoparticles for uses in biomedicine.