Dispersion and Functionalization of Nanoparticles Synthesized by Gas Aggregation Source: Opening New Routes Toward the Fabrication of Nanoparticles for Biomedicine

Abstract

The need to find new nanoparticles for biomedical applications is pushing the limits of the fabrication methods. New techniques with versatilities beyond the extended chemical routes can provide new insight in the field. In particular gas aggregation sources offer the possibility to fabricate nanoparticles with controlled size, composition and structure out of thermodynamics. In this context, the milestone is the optimization of the dispersion and functionalization processes of nanoparticles once fabricated by these routes as they are generated in the gas phase and deposited on substrates in vacuum or ultra-high vacuum conditions. In the present work we propose a fabrication route in ultra-high vacuum that is compatible with the subsequent dispersion and functionalization of nanoparticles in aqueous media and, that is more remarkable, in one single step. In particular, we will present the fabrication of nanoparticles with a sputter gas aggregation source, using a Fe 50 B 50 target, and their further dispersion and functionalization with polyethileneglycol (PEG). A characterization of these nanoparticles is carried out before and after PEG functionalization. During functionalization, significant boron dissolution occurs, which facilitates nanoparticle dispersion in the aqueous solution. The use of different complementary techniques allows us to prove the PEG attachment onto the surface of the nanoparticles creating a shell to make them biocompatible. The result is the formation of nanoparticles with a structure mainly composed by a metallic Fe core and an iron oxide shell, surrounded by a second PEG shell dispersed in aqueous solution. Relaxivitiy measurements of these PEG functionalized nanoparticles assessed their effectiveness as contrast agents for Magnetic Resonance Imaging (MRI) analysis. Therefore, this new fabrication route is a reliable alternative for the synthesis of nanoparticles for biomedicine.

One-Step Route to Iron Oxide Hollow Nanocuboids by Cluster Condensation: Implementation in Water Remediation Technology

“…According to the results above, we can speculate that such systems could be developed as auxiliary devices for water remediation or as sensors for detection and concentration measurements . Also, although the subsequent dispersion of such particles, from gas aggregation sources in aqueous solutions, is not an easy task, ultrasonication can assist that purpose …”

“…54 Also, although the subsequent dispersion of such particles, from gas aggregation sources in aqueous solutions, is not an easy task, ultrasonication can assist that purpose. 55…”

Active targeting of CD4+ T lymphocytes by PEI-capped, peptide-functionalized gold nanoparticles

“…The most complex construct (C) has the greatest polydispersity. Opera et al studied the dispersion of boron-functionalised nanoparticles using gas aggregation, and found that functionalisation led to an increase in particle dispersion [68].…”

Bimetallic Nanoparticles for Biomedical Applications: A Review

“…In general, the elements present in the NPs are similar or the exact ones on the target, but the internal structure of the compounds depends on the atomic diffusion of the two kinds of atoms. As an example, Oprea et al showed the fabrication of Fe-B NPs from a Fe50B50 target, which was made of an internal Fe core while outside the shell with a combination of Fe and B oxides and oxynitrides (Oprea et al 2015). They could be functionalized with polyethylene glycol (PEG) and exhibited superparamagnetic behavior at RT.…”