Direct Myocardial Injection of Vectors

Neonatal heart tissue-derived EVs alleviate adult ischemic cardiac injury via regulating the function of macrophages and cardiac regeneration in murine models

Previous studies confirmed the regenerative capacity of the mammalian neonatal heart. We recently found that adult heart tissue-derived EVs can protect the heart from myocardial ischemia-reperfusion (I/R). However, the role of EVs from neonatal heart tissue in cardiac healing post-ischemia remains unclear. In the present study, we revealed that intramyocardial administration of neonatal cardiac tissue-derived EVs (ncEVs) alleviated cardiac inflammation, mitigated reperfusion injury, and improved cardiac function in murine I/R models. In vitro, ncEVs inhibited M1 polarization of macrophages induced by LPS while up-regulated their phagocytic function via the miR-133a-3p-Ash1l signaling pathway. Moreover, the administration of ncEVs contributed to cardiac angiogenesis and improved cardiac function in murine myocardial infarction models. Collectively, these results suggested that neonatal heart-derived EVs can regulate the function of macrophages and contribute to cardiac regeneration and function recovery in murine cardiac ischemic models. Therefore, the derivatives in neonatal heart tissue-derived EVs might serve as a potential therapeutic strategy in ischemic diseases.

Gene therapy for atrial fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia in adults. Current limitations of pharmacological and ablative therapies motivate the development of novel therapies as next generation treatments for AF. The arrhythmia mechanisms creating and sustaining AF are key elements in the development of this novel treatment. Gene therapy provides a useful platform that allows us to regulate the mechanisms of interest using a suitable transgene(s), vector, and delivery method. Effective gene therapy strategies in the literature have targeted maladaptive electrical or structural remodeling that increase vulnerability to AF. In this review, we will summarize key elements of gene therapy for AF, including molecular targets, gene transfer vectors, atrial gene delivery and preclinical efficacy and toxicity testing. Recent advances and challenges in the field will be also discussed.

Atrial Gene Painting in Large Animal Model of Atrial Fibrillation

Gene therapy appears promising as a targeted treatment of cardiac diseases. Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and also a major contributor to stroke, heart failure, and death. Mechanisms that initiate and sustain AF are associated with structural and electrophysiological remodeling in the whole atria. Selection of the appropriate gene delivery method is critical for transduction efficacy. The ideal gene delivery method to manage AF should provide widespread and sufficient exposure to the transgene in atria only that safely maintains the homeostasis of the heart without off-target expression. All these requirements can be achieved using atrial gene painting that is directly applied to the atrial epicardial surface. In this chapter, we present the advantages of atrial gene painting and the experimental method, as applied to a large animal model of AF.

Therapeutic advances in cardiac targeted drug delivery: from theory to practice

The most commonly used administration methods in clinics and life are oral administration, intravenous injection, and other systemic administration methods. Targeted administration must be an essential long-term development direction due to the limited availability and a high incidence of systemic side effects. Cardiovascular diseases (CVD) are the leading cause of death all over the world. Targeted drug delivery (TDD) methods with the heart as the target organ have developed rapidly and are diversified. This article reviews the research progress of various TDD methods around the world with a heart as the target organ. It is mainly divided into two parts: the targeting vector represented by nanoparticles and various TDD methods such as intracoronary injection, ventricular wall injection, pericardial injection, and implantable medical device therapy and put forward some suggestions on the development of targeting. Different TDD methods described in this paper have not been widely used in clinical practice, and some have not even completed preclinical studies. Targeted drug delivery still requires long-term efforts by many researchers to realize the true meaning of the heart. HIGHLIGHTS Targeted administration can achieve a better therapeutic effect and effectively reduce the occurrence of adverse reactions. Parenteral administration or medical device implantation can be used for targeted drug delivery. Combined with new dosage forms or new technologies, better-targeted therapy can be achieved. Clinical trials have confirmed the safety and effectiveness of several administration methods.

AAV Vectors for Efficient Gene Delivery to Rodent Hearts

Currently, gene therapy is one of the most promising fields in biomedicine, with great therapeutic potential for an array of inherited and acquired diseases. Adeno-associated viral (AAV) vectors have emerged as promising tools to deliver selectively a therapeutic payload to target organs, including the heart. In this chapter, we describe the production and quality control of recombinant AAV (rAAV) vectors of the serotype 9, the most cardiotropic AAV serotype when delivered systemically in rodents. We also describe the systemic administration of rAAV vectors and the local delivery of rAAV vectors by direct intramyocardial injection. Taken together, the methods described in this chapter will allow the reader to deliver efficiently therapeutic genes to the rodent heart, both globally and regionally.

The Gene Therapy Resource Program: A Decade of Dedication to Translational Research by the National Heart, Lung, and Blood Institute

Over a 10-year period, the Gene Therapy Resource Program (GTRP) of the National Heart Lung and Blood Institute has provided a set of core services to investigators to facilitate the clinical translation of gene therapy. These services have included a preclinical (research-grade) vector production core; current Good Manufacturing Practice clinical-grade vector cores for recombinant adeno-associated virus and lentivirus vectors; a pharmacology and toxicology core; and a coordinating center to manage program logistics and to provide regulatory and financial support to early-phase clinical trials. In addition, the GTRP has utilized a Steering Committee and a Scientific Review Board to guide overall progress and effectiveness and to evaluate individual proposals. These resources have been deployed to assist 82 investigators with 172 approved service proposals. These efforts have assisted in clinical trial implementation across a wide range of genetic, cardiac, pulmonary, and blood diseases. Program outcomes and potential future directions of the program are discussed.