Thoracoscopic monitoring for pericardial application of local drug or gene therapy

Micronized Acellular Matrix Biomaterial Leverages Eosinophils for Postinfarct Cardiac Repair

After ischemic injury, immune cells mediate maladaptive cardiac remodeling. Extracellular matrix biomaterials may redirect inflammation toward repair. Pericardial fluid contains pro-reparative immune cells, potentially leverageable by biomaterials. Herein, we explore how pericardial delivery of a micronized extracellular matrix biomaterial affects cardiac healing. In noninfarcted mice, pericardial delivery increases pericardial and myocardial eosinophil counts. This response is sustained after myocardial infarction, stimulating an interleukin 4 rich milieu. Ultimately, the biomaterial improves postinfarct vascularization and cardiac function; and eosinophil-knockout negates these benefits. For the first time, to our knowledge, we demonstrate the therapeutic potential of pericardial biomaterial delivery and the eosinophil's critical role in biomaterial-mediated postinfarct repair.

Access routes, devices and guidance methods for intrapericardial delivery in cardiac conditions

Drug deposition into the intrapericardial space is favourable for achieving localised effects and targeted cardiac delivery owing to its proximity to the myocardium as well as facilitating optimised pharmacokinetic profiles and a reduction in systemic side effects. Access to the pericardium requires invasive procedures but the risks associated with this have been reduced with technological advances, such as combining transatrial and subxiphoid access with different guidance methods. A variety of introducer devices, ranging from needles to loop-catheters, have also been developed and validated in pre-clinical studies investigating intrapericardial delivery of therapeutic agents. Access techniques are generally well-tolerated, self-limiting and safe, although some rare complications associated with certain approaches have been reported. This review covers these access techniques and how they have been applied to the delivery of drugs, cells, and biologicals, demonstrating the potential of intrapericardial delivery for treatments in cardiac arrhythmia, vascular damage, and myocardial infarction.

A Minimally Invasive, Translational Method to Deliver Hydrogels to the Heart Through the Pericardial Space

Biomaterials are a new treatment strategy for cardiovascular diseases but are difficult to deliver to the heart in a safe, precise, and translatable way. We developed a method to deliver hydrogels to the epicardium through the pericardial space. Our device creates a temporary compartment for hydrogel delivery and gelation using anatomic structures. The method minimizes risk to patients from embolization, thrombotic occlusion, and arrhythmia. In pigs there were no clinically relevant acute or subacute adverse effects from pericardial hydrogel delivery, making this a translatable strategy to deliver biomaterials to the heart.

Delivery of gene and cellular therapies for heart disease

Although there has been considerable interest in the utilization of gene and cellular therapy for heart disease in recent years, there remain critical questions prior to widespread promotion of therapy, and key among these issues is the delivery method used for both gene therapy and cellular therapy. Much of the failure of gene and cellular therapy can be explained by the biological therapy itself; however, certainly there is a critical role played by the delivery technique, in particular, those that have been adapted from routine clinical use such as intravenous and intracoronary injection. Development of novel techniques to deliver gene and cellular therapy has ensued with some preclinical and even clinical success, though questions regarding safety, invasiveness, and repeatability remain. Here, we review techniques for gene and cellular therapy delivery, both existing and adapted techniques, and novel techniques that have emerged recently at promoting improved efficacy of therapy without the cost of systemic distribution. We also highlight key issues that need to be addressed to improve the chances of success of delivery techniques to enhance therapeutic benefit.