Advantages and Limitations of Current Techniques for Analyzing the Biodistribution of Nanoparticles

Abstract

Nanomedicines are typically submicrometer-sized carrier materials (nanoparticles) encapsulating therapeutic and/or imaging compounds that are used for the prevention, diagnosis and treatment of diseases. They are increasingly being used to overcome biological barriers in the body to improve the way we deliver compounds to specific tissues and organs. Nanomedicine technology aims to improve the balance between the efficacy and the toxicity of therapeutic compounds. Nanoparticles, one of the key technologies of nanomedicine, can exhibit a combination of physical, chemical and biological characteristics that determine their in vivo behavior. A key component in the translational assessment of nanomedicines is determining the biodistribution of the nanoparticles following in vivo administration in animals and humans. There are a range of techniques available for evaluating nanoparticle biodistribution, including histology, electron microscopy, liquid scintillation counting (LSC), indirectly measuring drug concentrations, in vivo optical imaging, computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine imaging. Each technique has its own advantages and limitations, as well as capabilities for assessing real-time, whole-organ and cellular accumulation. This review will address the principles and methodology of each technique and their advantages and limitations for evaluating in vivo biodistribution of nanoparticles.

Highly colloidally stable trimodal 125I-radiolabeled PEG-neridronate-coated upconversion/magnetic bioimaging nanoprobes

“…Among the probes, nanometer-sized particles in particular have been extensively utilized as contrast agents for anatomical and functional in vivo imaging 3 . Many imaging techniques, such as magnetic resonance imaging (MRI), X-ray computed tomography (CT), single photon emission computed tomography (SPECT), positron emission tomography (PET), ultrasound, optical imaging, and magnetic particle imaging (MPI) have been successfully used in preclinical research for noninvasive real-time monitoring of nanoprobe biodistribution in experimental animals 4 – 6 . Each of these methods has its own advantages and drawbacks.…”

“…In vivo optical imaging is compromised by poor penetration of the light into the tissue, which does not allow for quantitative analysis. To optimize imaging sensitivity, contrast probes should preferably emit light in the red or near-infrared (NIR) region (~ 600-1000 nm) 6,8 . CT provides a superb hard tissue contrast; however, it has a low soft tissue contrast and produces harmful ionizing radiation 9 .…”

Liver-Targeted Combination Therapy Basing on Glycyrrhizic Acid-Modified DSPE-PEG-PEI Nanoparticles for Co-delivery of Doxorubicin and Bcl-2 siRNA

“…To improve selectivity toward liver cancer cells, an effective strategy is to design nano-sized carrier to realize liver-targeted delivery (Shamay et al, 2018). Recently, nanoparticles have been proved to have the advantages in drug delivery with low system toxicity (Wei et al, 2015; Zeng et al, 2017; Arms et al, 2018). Many nano-sized drug delivery systems, such as natural and synthetic polymer nanoparticles, metal nanoparticles, and polymer-drug conjugates, have been investigated for delivery of anti-tumor drugs (Ekladious et al, 2018; Liu et al, 2018; Maeki et al, 2018).…”

Sugar and Polymer Excipients Enhance Uptake and Splice-Switching Activity of Peptide-Dendrimer/Lipid/Oligonucleotide Formulations

“…Fluorescence imaging is commonly used to evaluate the biodistribution of nanoparticles formulations. It has the advantages of being a highly sensitive, non-invasive and relatively simple method to conduct in most of the cases [50]. ON from all injections showed the highest accumulation in liver, followed by the gastrointestinal tract (GIT) and kidneys (Figure 8).…”