Flow cytometry evidence of human granulocytes interaction with polyhedral oligomeric silsesquioxanes: effect of nanoparticle charge

Abstract

Nanoparticles (NPs) entering the human body are immediately confronted with the innate part of human immune system. In particular, monocyte and neutrophil granulocytes readily clear particles by phagocytosis, even if in the case of NPs the uptake mechanism may be classified as macropinocytosis. Among engineered nanoparticles, in the last years, siliceous materials have emerged as promising materials for several applications ranging from catalysis to biomedical. The polyhedral oligomeric silsesquioxanes (POSS) are nanodimensional, easily synthesizable molecular compounds and POSS-based systems are promising carriers for biological molecules. In this work, the ability of human granulocytes to uptake positively and negatively charged POSS was measured using a simple flow cytometry analysis based on cell size modifications. The data obtained showed that after a 30 min exposure only positive NPs were uptaken by human granulocyte using both macropinocytosis and clathrin-mediated mechanisms as demonstrated by uptake inhibition mediated by amiloride and chlorpromazine.

Neutrophil and Nanoparticles Delivery to Tumor: Is It Going to Carry That Weight?

“…Thus, polyhedral oligomeric silsesquioxanes (POSS) are internalized by NΦs via CME and macropinocytosis. [ 88 ]…”

“…Thus, polyhedral oligomeric silsesquioxanes (POSS) are internalized by NΦs via CME and macropinocytosis. [88] The deciphering of NP uptake pathways is important because the internalization mechanisms are involved in the regulation of NΦ functional activity, and, therefore NPs capturing could alter the cell responses. CME plays a crucial role in signal integration from different stimuli affecting NΦs.…”

Interfacial Properties of Fully Condensed Functional Silsesquioxane: A Langmuir Monolayer Study

“…Most studies have been limited to assessment of toxicity and biodegradation. 17 the interaction with the living cell components. Such studies have been recently performed for antibiotics, 18 nanoparticles, 19 and many other substances.…”