Sustained release of milrinone delivered via microparticles in a rodent model of myocardial infarction

Application of Hydrogels in Cardiac Regeneration

Myocardial infarction (MI) is a leading cause of death globally. Due to limited cardiac regeneration, infarcted myocardial tissue is gradually replaced by cardiac fibrosis, causing cardiac dysfunction, arrhythmia, aneurysm, free wall rupture, and sudden cardiac death. Thus, the development of effective methods to promote cardiac regeneration is extremely important for MI treatment. In recent years, hydrogels have shown promise in various methods for cardiac regeneration. Hydrogels can be divided into natural and synthetic types. Different hydrogels have different features and can be cross-linked in various ways. Hydrogels are low in toxicity and highly stable. Since they have good biocompatibility, biodegradability, and transformability, moderate mechanical properties, and proper elasticity, hydrogels are promising biomaterials for promoting cardiac regeneration. They can be used not only as scaffolds for migration of stem cells, but also as ideal carriers for delivery of drugs, genetic materials, stem cells, growth factors, cytokines, and small molecules. In this review, the application of hydrogels in cardiac regeneration during or post-MI is discussed in detail. Hydrogels open a promising new area in cardiac regeneration for treating MI.

Drug-nutrient cocrystallization-driven strategy towards self-assembly of milrinone and ferulic acid provides an exemplification in perfecting in vitro/vivo characteristics of anti-heart failure drugs

The in vitro/vivo properties of the anti-heart failure drug milrinone were optimized by cocrystallizing with a nutraceutical, ferulic acid.

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.

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

Congestive heart failure is a fatal cardiovascular disease resulting in tissue necrosis and loss of cardiac contractile function. Inotropic drugs such as milrinone are commonly used to improve the myocardial contractility and heart function. However, milrinone is associated with severe side effects and lower circulation time. In this article, a novel protein nanoparticle formulation for heart-targeted delivery of milrinone has been designed and tested. The formulation was prepared using albumin protein conjugated with the targeting ligand, angiotensin II peptide to form nanoparticles following the ethanol desolvation method. The formulation was characterized for size, charge, and morphology and tested in a rat model of congestive heart failure to study pharmacokinetics, biodistribution, and efficacy. The overall cardiac output parameters were evaluated comparing the formulation with the control non-targeted drug, milrinone lactate. This formulation exhibited improved pharmacokinetics with a mean retention time of 123.7 min, half-life of 101.3 min, and clearance rate of 0.24 L/(kg*h). The targeted formulation also significantly improved ejection fraction and fractional shortening parameters thus improving cardiac function. This study demonstrates a new approach in delivering inotropic drugs such as milrinone for superior treatment of congestive heart failure.

Novel Milrinone Nanoformulation for Use in Cardiovascular Diseases: Preparation and in Vitro Characterization

Cardiovascular diseases are the leading causes of mortality across the globe. Over the years, various drug formulations and delivery methods have been tested for cardiac repair. Milrinone (MRN) is a widely known cardiac inotrope drug used for the treatment of congestive heart failure in patients, however, its efficacy is limited. This study is the first to report the design of a novel MRN-nanoformulation using human serum albumin nanoparticles (HSA-NPs). The HSA-NPs exhibit promising drug delivery characteristics, such as target specificity, nonimmunogenicity, biocompatibility, and enhanced bioavailability. This article describes a MRN-nanoformulation design for in vitro drug release, cellular uptake, biocompatibility, and other features. The MRN-nanoformulation was prepared by the ethanol desolvation technique and key parameters were optimized to obtain a desired particle size of 154.2 ± 5.8 nm, zeta potential of -29.5 ± 2.9 mV, and a drug encapsulation efficiency of 41.1 ± 1.7%. Molecular docking studies have revealed that MRN binds in the hydrophobic cavity of HSA, which has also been indicated by circular dichroism and enzyme-mediated drug release studies in the presence of trypsin, pepsin, proteinase K, protease, and cathepsin D. The intracellular uptake of fluorescently tagged MRN-HSA-NPs using HUVEC and H9c2 cells was evaluated by flow cytometry. The nanoparticle toxicity results indicated that MRN-HSA-NPs show significantly lower cytotoxicity and higher cell viability ( P < 0.0001) as compared to the MRN-lactate drug in HUVEC (61.6 ± 3.7% vs 36.2 ± 2.9%) and H9c2 (58.8 ± 5.7% vs 18.8 ± 4.9%) cells. These studies indicate that the novel MRN-nanoformulation offers better drug delivery procedures than currently used methods and has potential in treatment of congestive heart failure and other cardiovascular diseases.

Strategies to develop endogenous stem cell-recruiting bioactive materials for tissue repair and regeneration

A leading strategy in tissue engineering is the design of biomimetic scaffolds that stimulate the body's repair mechanisms through the recruitment of endogenous stem cells to sites of injury. Approaches that employ the use of chemoattractant gradients to guide tissue regeneration without external cell sources are favored over traditional cell-based therapies that have limited potential for clinical translation. Following this concept, bioactive scaffolds can be engineered to provide a temporally and spatially controlled release of biological cues, with the possibility to mimic the complex signaling patterns of endogenous tissue regeneration. Another effective way to regulate stem cell activity is to leverage the inherent chemotactic properties of extracellular matrix (ECM)-based materials to build versatile cell-instructive platforms. This review introduces the concept of endogenous stem cell recruitment, and provides a comprehensive overview of the strategies available to achieve effective cardiovascular and bone tissue regeneration.

Microparticles in Chronic Heart Failure

Heart failure (HF) continues to have a sufficient impact on morbidity, mortality, and disability in developed countries. Growing evidence supports the hypothesis that microparticles (MPs) might contribute to the pathogenesis of the HF development playing a pivotal role in the regulation of the endogenous repair system, thrombosis, coagulation, inflammation, immunity, and metabolic memory phenomenon. Therefore, there is a large body of data clarifying the predictive value of MP numerous in circulation among subjects with HF. Although the determination of MP signature is better than measurement of single MP circulating level, there is not yet close confirmation that immune phenotype of cells produced MPs are important for HF prediction and development. The aim of the chapter is to summarize knowledge regarding the role of various MPs in diagnosis and prognosis of HF. The role of MPs as a delivery vehicle for drugs attenuated cardiac remodeling is considered.

Towards comprehensive cardiac repair and regeneration after myocardial infarction: Aspects to consider and proteins to deliver

Ischemic heart disease is a leading cause of death worldwide. After the onset of myocardial infarction, many pathological changes take place and progress the disease towards heart failure. Pathologies such as ischemia, inflammation, cardiomyocyte death, ventricular remodeling and dilation, and interstitial fibrosis, develop and involve the signaling of many proteins. Proteins can play important roles in limiting or countering pathological changes after infarction. However, they typically have short half-lives in vivo in their free form and can benefit from the advantages offered by controlled release systems to overcome their challenges. The controlled delivery of an optimal combination of proteins per their physiologic spatiotemporal cues to the infarcted myocardium holds great potential to repair and regenerate the heart. The effectiveness of therapeutic interventions depends on the elucidation of the molecular mechanisms of the cargo proteins and the spatiotemporal control of their release. It is likely that multiple proteins will provide a more comprehensive and functional recovery of the heart in a controlled release strategy.