Staff member

Azzurra Apriceno

Postdoctoral Researcher
Molecular Bionics

Staff member publications

Liu, M., Apriceno, A., Sipin, M., Scarpa, E., Rodriguez-Arco, L., Poma, A., Marchello, G., Battaglia, G., Angioletti-Uberti, S., (2020). Combinatorial entropy behaviour leads to range selective binding in ligand-receptor interactions Nature Communications 11, (1), 4836

From viruses to nanoparticles, constructs functionalized with multiple ligands display peculiar binding properties that only arise from multivalent effects. Using statistical mechanical modelling, we describe here how multivalency can be exploited to achieve what we dub range selectivity, that is, binding only to targets bearing a number of receptors within a specified range. We use our model to characterise the region in parameter space where one can expect range selective targeting to occur, and provide experimental support for this phenomenon. Overall, range selectivity represents a potential path to increase the targeting selectivity of multivalent constructs.

Williams, I., Lee, S., Apriceno, A., Sear, R. P., Battaglia, G., (2020). Diffusioosmotic and convective flows induced by a nonelectrolyte concentration gradient Proceedings of the National Academy of Sciences of the United States of America 117, (41), 25263-25271

Glucose is an important energy source in our bodies, and its consumption results in gradients over length scales ranging from the subcellular to entire organs. Concentration gradients can drive material transport through both diffusioosmosis and convection. Convection arises because concentration gradients are mass density gradients. Diffusioosmosis is fluid flow induced by the interaction between a solute and a solid surface. A concentration gradient parallel to a surface creates an osmotic pressure gradient near the surface, resulting in flow. Diffusioosmosis is well understood for electrolyte solutes, but is more poorly characterized for nonelectrolytes such as glucose. We measure fluid flow in glucose gradients formed in a millimeter-long thin channel and find that increasing the gradient causes a crossover from diffusioosmosis-dominated to convection-dominated flow. We cannot explain this with established theories of these phenomena which predict that both scale linearly. In our system, the convection speed is linear in the gradient, but the diffusioosmotic speed has a much weaker concentration dependence and is large even for dilute solutions. We develop existing models and show that a strong surface-solute interaction, a heterogeneous surface, and accounting for a concentration-dependent solution viscosity can explain our data. This demonstrates how sensitive nonelectrolyte diffusioosmosis is to surface and solution properties and to surface-solute interactions. A comprehensive understanding of this sensitivity is required to understand transport in biological systems on length scales from micrometers to millimeters where surfaces are invariably complex and heterogeneous.

Keywords: Convection, Diffusioosmosis, Microfluidics

Tian, Xiaohe, Leite, Diana M., Scarpa, Edoardo, Nyberg, Sophie, Fullstone, Gavin, Forth, Joe, Matias, Diana, Apriceno, Azzurra, Poma, Alessandro, Duro-Castano, Aroa, Vuyyuru, Manish, Harker-Kirschneck, Lena, Šarić, Zhang, Zhongping, Xiang, Pan, Fang, Bin, Tian, Yupeng, Luo, Lei, Rizzello, Loris, Battaglia, Giuseppe, (2020). On the shuttling across the blood-brain barrier via tubule formation: Mechanism and cargo avidity bias Science Advances 6, (48), eabc4397

The blood-brain barrier is made of polarized brain endothelial cells (BECs) phenotypically conditioned by the central nervous system (CNS). Although transport across BECs is of paramount importance for nutrient uptake as well as ridding the brain of waste products, the intracellular sorting mechanisms that regulate successful receptor-mediated transcytosis in BECs remain to be elucidated. Here, we used a synthetic multivalent system with tunable avidity to the low-density lipoprotein receptor–related protein 1 (LRP1) to investigate the mechanisms of transport across BECs. We used a combination of conventional and super-resolution microscopy, both in vivo and in vitro, accompanied with biophysical modeling of transport kinetics and membrane-bound interactions to elucidate the role of membrane-sculpting protein syndapin-2 on fast transport via tubule formation. We show that high-avidity cargo biases the LRP1 toward internalization associated with fast degradation, while mid-avidity augments the formation of syndapin-2 tubular carriers promoting a fast shuttling across.