Influence of Size and Shape on the Anatomical Distribution of Endotoxin-Free Gold Nanoparticles

Abstract

The transport and the delivery of drugs through nanocarriers is a great challenge of pharmacology. Since the production of liposomes to reduce the toxicity of doxorubicin in patients, a plethora of nanomaterials have been produced and characterized. Although it is widely known that elementary properties of nanomaterials influence their in vivo kinetics, such interaction is often poorly investigated in many preclinical studies. The present study aims to evaluate the actual effect of size and shape on the biodistribution of a set of gold nanoparticles (GNPs) after intravenous administration in mice. To this goal, quantitative data achieved by inductively coupled plasma mass spectrometry and observational results emerging from histochemistry (autometallography and enhanced dark-field hyperspectral microscopy) were combined. Since the immune system plays a role in bionano-interaction we used healthy immune-competent mice. To keep the immune surveillance on the physiological levels we synthesized endotoxin-free GNPs to be tested in specific pathogen-free animals. Our study mainly reveals that (a) the size and the shape greatly influence the kinetics of accumulation and excretion of GNPs in filter organs; (b) spherical and star-like GNPs showed the same percentage of accumulation, but a different localization in liver; (c) only star-like GNPs are able to accumulate in lung; (d) changes in the geometry did not improve the passage of the blood brain barrier. Overall, this study can be considered as a reliable starting point to drive the synthesis and the functionalization of potential candidates for theranostic purposes in many fields of research.

Nanoparticle Characterization: What to Measure?

“…Although often assumed spherical, nanoparticles feature a large variety of geometric and irregular shapes . Particles with equal composition and similar dimensions might present drastically different behaviors as a consequence of their shape, such as surface‐binding capability, cellular uptake and release, optical and plasmonic effects, to name some of the major properties affected by particle morphology.…”

Engineering of inorganic nanoparticles as magnetic resonance imaging contrast agents

“…The dependence of cellular uptake, biodistribution, and clearance rate on NP size has been widely investigated by many groups. 111-115 To date, several types of CAs have been developed for various applications in MRI, which can be classified according to their chemical composition (Gd-, Mn-, Fe-, Dy- or Ho-based CAs; Table 2). A deep understanding of the involved mechanisms between size effect and proton relaxation will undoubtedly benefit the rational design of T 1 or T 2 CAs for high-performance MRI.…”

Effects of engineered nanoparticles on the innate immune system

“…They found that all types of NPs induced complement activation (through measurements of C3bc, C3a, C5a, and sC5b-9) within the first 5 minutes of contact with blood, but rods and disks generate more profound complement activation than spheres at later timepoints [40]. Recently, Bigini et al demonstrated that spherical and star-like Au NPs show the same percentage of accumulation but a different localization in liver, and only star-like Au NPs could be able to accumulate in lung [41]. …”