The progress of Engineered Nano-Materials (ENMs) designed for medical application is certainly promising. Our main endeavour is the identification of potential bio-safety risks connected to ENMs.

We focus our attention on specific features of organic ENMs designed for drug/gene delivery that may harm cell viability and stimulate immune responses, with special attention to the Central Nervous System (CNS) and Blood Immune Cells.

Nano-toxicity research within NPT division @CNI integrates the Nanomedicine division' project aimed at the development of pre-clinical nano-carriers for drug/gene delivery into the CNS. This ambitious project foresees the systemic release of drug loaded ENMs. Inevitably, such engineered materials face immune surveillance in the bloodstream and within the target tissue. As non-self particles, ENMs developed to delivering drugs may result in deleterious modulation of immune responses.

Particles whose size is below 100nm may have direct effects on cells membrane protein receptors, lipid and carbohydrate arrangement. ENM-surface modification with chemical moieties (functionalization), which is aimed at the specific goal ENMs have been prepared for, represents the most crucial aspect to be considered to investigate their potential harmful outcome.

Systemically administered ENMs bind serum molecules which could mediate inflammatory reaction. Functionalization mediated serum protein adsorption, called (protein corona), may modify the physical and chemical characteristics (size, charge, shape, solubility, etc...) of nano-carriers their level of biocompatibility.

Our strategy of ENM induced immunogenic response is based on their capacity to provoke functional activation of immune cells either in the blood or in CNS. Special attention is placed on ENM-mediated release of inflammatory cytokines and chemokines by endothelial and white blood cell, as well as neurons and astrocytes in the CNS (our major target tissue). The foreseen outcome will be a consequent modulation of chemokine receptors' expression on monocytes, lymphocytes and microglia (the CNS resident immune cells) and subsequent inflammatory driven migration of these immune responsible cells.

Fig.1: In vitro model of Central Nervous System (CNS) resident immune system cell activation. Primary neural cells will be purified and cultured separately: neurons and astrocytes (1st culture); microglia, the resident immune cells in the CNS (2nd culture). Engineered nanomaterials will be administered to the cultures in order to evaluate functional activation ( i.e. migration) of microglia.

Albeit a general immune reaction is expected, a prolonged and out-of-control immune activation may define the bio-safety profile of the chosen ENMs and help the designing of bio-mimetic engineering of nanoparticles for biomedical applications.

Our central ENM models for drug/gene delivery are polymeric nanoparticles such as PLGA, PLA, and Dendrimers produced in house, as well as engineered peptides. As promising carriers for small RNAs we focus on lipoplexes in collaboration with Dr Giulio Caracciolo (Univ. La Sapienza, Roma). Inorganic nanoparticles are also investigated in our labs, since some of these particles have demonstrated to be very useful for in vitro and in vivo imaging purposes (e.g. magnetic nanoparticles for MRI, and Quantum dot-doped Silica nanoparticles, through a collaboration with Dr Piero Pompa IIT@Unile).

Our challenge to study the interactions of nanoparticles with cells and tissues employs nanotoxicology lab ideal tools for immunology (i.e. primary cell preparation facility, 7-color Flow Cytometry, Multi-Mode Microplate Reader). Moreover, we apply a range of advanced techniques for the characterization of ENM interactions with cells and tissues: Transmission Electron Microscopy, confocal/2-photon microscopy, "CARS" (coherent anti-Stokes Raman spectroscopy, providing complementary and invaluable information on ENM intracellular fate and subsequent bio-safety.