Nanoparticles for Cardiovascular Imaging and Therapeutic Delivery, Part 1: Compositions and Features

Abstract

Imaging agents made from nanoparticles are functionally versatile and have unique properties that may translate to clinical utility in several key cardiovascular imaging niches. Nanoparticles exhibit size-based circulation, biodistribution, and elimination properties different from those of small molecules and microparticles. In addition, nanoparticles provide versatile platforms that can be engineered to create both multimodal and multifunctional imaging agents with tunable properties. With these features, nanoparticulate imaging agents can facilitate fusion of high-sensitivity and high-resolution imaging modalities and selectively bind tissues for targeted molecular imaging and therapeutic delivery. Despite their intriguing attributes, nanoparticulate imaging agents have thus far achieved only limited clinical use. The reasons for this restricted advancement include an evolving scope of applications, the simplicity and effectiveness of existing small-molecule agents, pharmacokinetic limitations, safety concerns, and a complex regulatory environment. This review describes general features of nanoparticulate imaging agents and therapeutics and discusses challenges associated with clinical translation. A second, related review to appear in a subsequent issue of JNM highlights nuclear-based nanoparticulate probes in preclinical cardiovascular imaging.

Tunable and noncytotoxic PET/SPECT-MRI multimodality imaging probes using colloidally stable ligand-free superparamagnetic iron oxide nanoparticles

“…22 These challenges are likely the reason why nanoparticle platforms remain limited to preclinical use, despite their potential applications in theranostics. 23 Our previous studies showed that the sterically stabilized superparamagnetic iron oxide nanoparticles (s-SPIONs) were stable under physiological conditions, noncytotoxic in vitro, and have shown potential biomedical applications in drug delivery and stem cell tracking. 11,24 Our recent publication further demonstrated that these sterically stabilized SPIONs were highly stable and well dispersed after being mixed with fresh human red blood cells.…”

Atherosclerosis Treatment with Stimuli‐Responsive Nanoagents: Recent Advances and Future Perspectives

“…The potential of nanoparticles as agents for molecular imaging is continuously growing, alongside the need to develop better imaging techniques, improve imaging quality, and facilitate multimodal imaging for precise diagnosis . Instead of positron emission tomography (PET) that uses radionuclides, such as 18 F, 11 C, 13 N, and 15 O and single photon emission computed tomography (SPECT) that uses radioisotopes, such as 99m Tc, 123 I, and 131 I, recent developments of contrast agents allow magnetic resonance imaging (MRI), contrast‐enhanced ultrasound (CEUS) imaging, near‐infrared fluorescence (NIRF) imaging, and photoacoustic imaging (PAI) as molecular imaging modalities, which can be combined to achieve multimodal imaging …”

Vascular targeting of nanoparticles for molecular imaging of diseased endothelium

“…To this end, some efforts have focused on macrophage imaging, but because rodent and rabbit models have significantly higher macrophage counts than humans, in vivo studies have often not been accurate at correctly depicting human disease. Here, we focus on vascular molecular targeting and imaging of the atherosclerotic endothelium via over-expressed endothelial cell markers using prevalent imaging modalities [52,53]. Given that the process of atherosclerotic plaque formation is similar between humans and current animal models with respect to changes in the vascular endothelium, to our knowledge to date, there are no significant discrepancies in clinical translation of results from animal models of the disease.…”