Albumin Nanoparticle Formulation for Heart-Targeted Drug Delivery: In Vivo Assessment of Congestive Heart Failure

Dendritic amphiphilic siRNA: Selective albumin binding, in vivo efficacy, and low toxicity

Although an increasing number of small interfering RNA (siRNA) therapies are reaching the market, the challenge of efficient extra-hepatic delivery continues to limit their full therapeutic potential. Drug delivery vehicles and hydrophobic conjugates are being used to overcome the delivery bottleneck. Previously, we reported a novel dendritic conjugate that can be appended efficiently to oligonucleotides, allowing them to bind albumin with nanomolar affinity. Here, we explore the ability of this novel albumin-binding conjugate to improve the delivery of siRNA in vivo. We demonstrate that the conjugate binds albumin exclusively in circulation and extravasates to various organs, enabling effective gene silencing. Notably, we show that the conjugate achieves a balance between hydrophobicity and safety, as it significantly reduces the side effects associated with siRNA interactions with blood components, which are commonly observed in some hydrophobically conjugated siRNAs. In addition, it reduces siRNA monocyte uptake, which may lead to cytokine/inflammatory responses. This work showcases the potential of using this dendritic conjugate as a selective albumin binding handle for the effective and safe delivery of nucleic acid therapeutics. We envision that these properties may pave the way for new opportunities to overcome delivery hurdles of oligonucleotides in future applications.

Advanced Drug Delivery Micro- and Nanosystems for Cardiovascular Diseases

Advanced drug delivery micro- and nanosystems have been widely explored due to their appealing specificity/selectivity, biodegradability, biocompatibility, and low toxicity. They can be applied for the targeted delivery of pharmaceuticals, with the benefits of good biocompatibility/stability, non-immunogenicity, large surface area, high drug loading capacity, and low leakage of drugs. Cardiovascular diseases, as one of the primary mortalities cause worldwide with significant impacts on the quality of patients’ life, comprise a variety of heart and circulatory system pathologies, such as peripheral vascular diseases, myocardial infarction, heart failure, and coronary artery diseases. Designing novel micro- and nanosystems with suitable targeting properties and smart release behaviors can help circumvent crucial challenges of the tolerability, low stability, high toxicity, and possible side- and off-target effects of conventional drug delivery routes. To overcome different challenging issues, namely physiological barriers, low efficiency of drugs, and possible adverse side effects, various biomaterials-mediated drug delivery systems have been formulated with reduced toxicity, improved pharmacokinetics, high bioavailability, sustained release behavior, and enhanced therapeutic efficacy for targeted therapy of cardiovascular diseases. Despite the existing drug delivery systems encompassing a variety of biomaterials for treating cardiovascular diseases, the number of formulations currently approved for clinical use is limited due to the regulatory and experimental obstacles. Herein, the most recent advancements in drug delivery micro- and nanosystems designed from different biomaterials for the treatment of cardiovascular diseases are deliberated, with a focus on the important challenges and future perspectives.

Nanoparticles Targeting the Molecular Pathways of Heart Remodeling and Regeneration

Cardiovascular diseases are the main cause of death worldwide, a trend that will continue to grow over the next decade. The heart consists of a complex cellular network based mainly on cardiomyocytes, but also on endothelial cells, smooth muscle cells, fibroblasts, and pericytes, which closely communicate through paracrine factors and direct contact. These interactions serve as valuable targets in understanding the phenomenon of heart remodeling and regeneration. The advances in nanomedicine in the controlled delivery of active pharmacological agents are remarkable and may provide substantial contribution to the treatment of heart diseases. This review aims to summarize the main mechanisms involved in cardiac remodeling and regeneration and how they have been applied in nanomedicine.

Synthesis and characterization of peptide conjugated human serum albumin nanoparticles for targeted cardiac uptake and drug delivery

Congestive heart failure, a prominent cardiovascular disease results primarily from myocardial infarction or ischemia. Milrinone (MRN), a widely used clinical drug for heart failure, improves myocardial contractility and cardiac function through its inotropic and vasodilatory effects. However, lacking target specificity, it exhibits low bioavailability and lower body retention time. Therefore, in this study, angiotensin II (AT1) peptide conjugated human serum albumin nanoparticles (AT1-HSA-MRN-NPs) have been synthesized for targeted delivery of MRN to the myocardium, overexpressing AT1 receptors under heart failure. The NPs were surface functionalized through a covalent conjugation reaction between HSA and AT1. Nanoparticle size was 215.2±4.7 nm and zeta potential -28.8±2.7 mV and cumulative release of MRN was ~72% over 24 hrs. The intracellular uptake of nanoparticles and cell viability was studied in H9c2 cells treated with AT1-MRN-HSA-NPs vs the control non-targeted drug, MRN Lactate under normal, hypoxic and hypertrophic conditions. The uptake of AT1-HSA-MRN-NPs in H9c2 cells was significantly higher as compared to non-targeted nanoparticles, and the viability of H9c2 cells treated with AT1-MRN-HSA-NPs vs MRN Lactate was 73.4±1.4% vs 44.9±1.4%, respectively. Therefore, AT1-HSA-MRN-NPs are safe for in vivo use and exhibit superior targeting and drug delivery characteristics for treatment of heart failure.

The role of anti-inflammatory drugs and nanoparticle-based drug delivery models in the management of ischemia-induced heart failure

Ongoing advancements in the treatment of acute myocardial infarction (MI) have significantly decreased MI related mortality. Consequently, the number of patients experiencing post-MI heart failure (HF) has continued to rise. Infarction size and the extent of left ventricular (LV) remodeling are largely determined by the extent of ischemia at the time of myocardial injury. In the setting of MI or acute phase of post-MI LV remodeling, anti-inflammatory drugs including intravenous immunoglobulin (IVIG) and Pentoxifylline have shown potential efficacy in preventing post-MI remodeling in-vitro and in some clinical trials. However, systemic administration of anti-inflammatory drugs are not without their off-target side effects. Herein, we explore the clinical feasibility of targeted myocardial delivery of anti-inflammatory drugs via biodegradable polymers, liposomes, hydrogels, and nano-particle based drug delivery models (NDDM) based on existing pre-clinical and clinical models. We summarize the barriers to clinical application of targeted anti-inflammatory delivery post-MI, including challenges in achieving sufficient retention and distribution, as well as the potential need for multiple dosing. Collectively, we suggest that localized delivery of anti-inflammatory agents to the myocardium using NDDM is a promising approach for successful treatment of ischemic HF. Future studies will be instrumental in determining the most effective target and delivery modalities for orchestrating NDDM-mediated treatment of HF.