Green Nanovectors for Phytodrug Delivery: In-Depth Structural and Morphological Characterization

Lipid-based soft nanovectors are widely used for delivery purposes in many fields of applications. Although it is generally considered a class of molecules with superior biocompatibility, in recent times researchers have expressed concerns with regards to the sustainability of preparation procedures. In particular, when large-scale production is involved, as in the case of agro-nanotechnology applications, this becomes a most pressing issue. Recently, we proposed novel green nanoformulations for the delivery of phytohormones (i.e., indole-3-butyric acid and 1-naphthaleneacetic acid) to Olea europaea L., obtained from agricultural waste derived from the plant itself, which yielded promising results, especially when engineered by addition of pure phospholipids in small amounts (10% w/w). Here we have performed an advanced analysis of high-resolution structural data from X-ray and neutron scattering (SAXS/SANS) and cryo-transmission electron microscopy (cryo-TEM). The results obtained from these combined techniques were complementary and fully consistent, evidencing the fundamental role of the employed adjuvant phospholipid in dictating the structural arrangement.