FL 13 - Towards the Preparative Isolation of Royal Jelly-Derived Nanotransporters for Innovative Nanomedical Formulations

Stefano Giordania,b,c, Virginia Rondininia, Vedrana Krušić Alićd, Anna Placcia,b,c, Andrea Zattonia,b,c, Barbara Rordaa,b,c, Pierluigi Reschigliana,b,c, Mladenka Malenicae, Valentina Marassia,b,c

aDepartment of Chemistry, University of Bologna, 40129 Bologna, Italy,
bbyFlow S.r.l., 40129 Bologna, Italy,
cBiostructures and Biosystems National Institute (INBB), 00136 Rome, Italy,
dDepartment of Physiology, Immunology and Pathophysiology, University of Rijeka, 51000 Rijeka, Croatia,
eDepartment of Medical Chemistry, Biochemistry and Clinical Chemistry, University of Rijeka, 51000 Rijeka, Croatia;

The bioavailability of bioactive compounds is often limited by their instability and poor solubility, and they are therefore commonly incorporated into synthetic carriers, primarily liposomes. However, due to the low biocompatibility of synthetic carriers, increasing attention is being directed toward natural sources. Nanoparticles derived from bee products (honey and royal jelly) represent an innovative alternative, with the potential to improve bioavailability, selectivity, and targeted release. Morphologically, they resemble extracellular vesicles, membrane-bound structures that transport lipids, proteins, and nucleic acids, capable of crossing physiological barriers and being internalized by cells. While antibacterial and regenerative properties of bee product–derived nanoparticles have already been reported, their potential as nano-carriers for the encapsulation of bioactive compounds remains almost completely unexplored. In this work, we report the development of a multidetection asymmetrical flow field-flow fractionation (AF4-MD) method designed to separate and characterize nanoscale components from royal jelly (RJ) samples. This technique enables size-based separation and multiparametric characterization (radius, mass, spectroscopic properties) of complex samples without pretreatment and under native or formulation conditions. The developed method allowed the separation of the analyzed samples into multiple distinct subpopulations, differing in composition and size, and the identification of populations specific to different RJ samples. Owing to the inherently gentle nature of AF4-MD separation, the collected fractions could be further analyzed by atomic force microscopy (AFM). This technique not only confirmed AF4-MD results but also provided additional insights into particle concentration, shape, and size within each fraction, enabling the identification of the most promising ones in terms of transporters content. Finally, since the developed method is based on the use of a semi-preparative AF4 channel, it can be readily scaled in terms of injected sample quantity. This allows the isolation of larger amounts of nanovectors as a basis for the development of a preparative pipeline towards the large-scale development of innovative nanomedical formulations.

Keywords: carotenoids, RPLC, UV-Vis, IMS

References

1. Royal Jelly, Nanotransporters, Asymmetrical Flow Field-Flow Fractionation, Multiparametric Characterization