Iron Oxide Nanoparticles as Contrast Agents in Molecular Magnetic Resonance Imaging: Do They Open New Perspectives in Cardiovascular Imaging?

Nanoparticle Polymers Influence on Cardiac Health: Good or Bad for Cardiac Physiology?

Cardiovascular diseases (CVD) are one of the leading causes of death and morbidity worldwide. Lifestyle modifications, medications, and addressing epidemiological factors have long been at the forefront of targeting therapeutics for CVD. Treatments can be further complicated given the intersection of gender, age, unique comorbidities, and healthcare access, among many other factors. Therefore, expanding treatment and diagnostic modalities for CVD is absolutely necessary. Nanoparticles and nanomaterials are increasingly being used as therapeutic and diagnostic modalities in various disciplines of biomedicine. Nanoparticles have multiple ways of interacting with the cardiovascular system. Some of them alter cardiac physiology by impacting ion channels, whereas others influence ions directly or indirectly, improving cellular death via decreasing oxidative stress.  While embedding nanoparticles into therapeutics can help enhance healthy cardiovascular function in other scenarios, they can also impair physiology by increasing reactive oxidative species and leading to cardiotoxicity. This review explores different types of nanoparticles, their effects, and the applicable dosages to create a better foundation for understanding the current research findings.

Heparin-Superparamagnetic Iron Oxide Nanoparticles for Theranostic Applications

In this study, superparamagnetic iron oxide nanoparticles (SPIONs) were engineered with an organic coating composed of low molecular weight heparin (LMWH) and bovine serum albumin (BSA), providing heparin-based nanoparticle systems (LMWH@SPIONs). The purpose was to merge the properties of the heparin skeleton and an inorganic core to build up a targeted theranostic nanosystem, which was eventually enhanced by loading a chemotherapeutic agent. Iron oxide cores were prepared via the co-precipitation of iron salts in an alkaline environment and oleic acid (OA) capping. Dopamine (DA) was covalently linked to BSA and LMWH by amide linkages via carbodiimide coupling. The following ligand exchange reaction between the DA-BSA/DA-LMWH and OA was conducted in a biphasic system composed of water and hexane, affording LMWH@SPIONs stabilized in water by polystyrene sulfonate (PSS). Their size and morphology were investigated via dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. The LMWH@SPIONs’ cytotoxicity was tested, showing marginal or no toxicity for samples prepared with PSS at concentrations of 50 µg/mL. Their inhibitory activity on the heparanase enzyme was measured, showing an effective inhibition at concentrations comparable to G4000 (N-desulfo-N-acetyl heparin, a non-anticoagulant and antiheparanase heparin derivative; Roneparstat). The LMWH@SPION encapsulation of paclitaxel (PTX) enhanced the antitumor effect of this chemotherapeutic on breast cancer cells, likely due to an improved internalization of the nanoformulated drug with respect to the free molecule. Lastly, time-domain NMR (TD-NMR) experiments were conducted on LMWH@SPIONs obtaining relaxivity values within the same order of magnitude as currently used commercial contrast agents.

Nano-Biomaterials for the Delivery of Therapeutic and Monitoring Cues for Aortic Diseases

The aorta is the largest artery in the body, so any diseases or conditions which could cause damage to the aorta would put patients at considerable and life-threatening risk. In the management of aortic diseases, the major treatments include drug therapy, endovascular treatment, and surgical treatment, which are of great danger or with a poor prognosis. The delivery of nano-biomaterials provides a potential development trend and an emerging field where we could monitor patients’ conditions and responses to the nanotherapeutics. One of the putative applications of nanotechnology is ultrasensitive monitoring of cardiovascular markers by detecting and identifying aneurysms. Moreover, the use of nanosystems for targeted drug delivery can minimize the systemic side effects and enhance drug positioning and efficacy compared to conventional drug therapies. This review shows some examples of utilizing nano-biomaterials in in vitro organ and cell culture experiments and explains some developing technologies in delivering and monitoring regenerative therapeutics.

Recent progress on nanoparticles for targeted aneurysm treatment and imaging

An abdominal aortic aneurysm (AAA) is a localized dilatation of the aorta that plagues millions. Its rupture incurs high mortality rates (~80-90%), pressing an urgent need for therapeutic methods to prevent this deadly outcome. Judiciously designed nanoparticles (NPs) have displayed a unique potential to fulfill this need. Aneurysms feature excessive inflammation and extracellular matrix (ECM) degradation. As such, typically inflammatory cells and exposed ECM proteins have been targeted with NPs for therapeutic, diagnostic, or theranostic purposes in experimental models. NPs have been used not only for encapsulation and delivery of drugs and biomolecules in preclinical tests, but also for enhanced imaging to monitor aneurysm progression in patients. Moreover, they can be readily modified with various molecules to improve lesion targeting, detectability, biocompatibility, and circulation time. This review updates on the progress, limitations, and prospects of NP applications in the context of AAA.

Application of Light Scattering Techniques to Nanoparticle Characterization and Development

Over the years, the scientific importance of nanoparticles for biomedical applications has increased. The high stability and biocompatibility, together with the low toxicity of the nanoparticles developed lead to their use as targeted drug delivery systems, bioimaging systems, and biosensors. The wide range of nanoparticles size, from 10 nm to 1 μm, as well as their optical properties, allow them to be studied using microscopy and spectroscopy techniques. In order to be effectively used, the physicochemical properties of nanoparticle formulations need to be taken into account, namely, particle size, surface charge distribution, surface derivatization and/or loading capacity, and related interactions. These properties need to be optimized considering the final nanoparticle intended biodistribution and target. In this review, we cover light scattering based techniques, namely dynamic light scattering and zeta-potential, used for the physicochemical characterization of nanoparticles. Dynamic light scattering is used to measure nanoparticles size, but also to evaluate their stability over time in suspension, at different pH and temperature conditions. Zeta-potential is used to characterize nanoparticles surface charge, obtaining information about their stability and surface interaction with other molecules. In this review, we focus on nanoparticle characterization and application in infection, cancer and cardiovascular diseases.

Use of Nanoparticles As Contrast Agents for the Functional and Molecular Imaging of Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is a degenerative disease of the aorta common in adults older than 65 years of age. AAA is usually imaged using ultrasound or computed tomography. Molecular imaging technologies employing nanoparticles (NPs) have been proposed as novel ways to quantify pathological processes, such as inflammation, within AAAs as a means to identify the risk of rapid progression or rupture. This article reviews the current evidence supporting the role of NP-based imaging in the management of AAA. Currently, ultrasmall superparamagnetic NPs enhanced magnetic resonance imaging appears to hold the greatest potential for imaging macrophage-mediated inflammation in human AAA.