Delivery of nano-objects to functional sub-domains of healthy and failing cardiac myocytes

Nanomedicines for Endothelial Disorders

The endothelium lines the internal surfaces of blood and lymphatic vessels and has a critical role in maintaining homeostasis. Endothelial dysfunction is involved in the pathology of many diseases and conditions, including disorders such as diabetes, cardiovascular diseases, and cancer. Given this common etiology in a range of diseases, medicines targeting an impaired endothelium can strengthen the arsenal of therapeutics. Nanomedicine - the application of nanotechnology to healthcare - presents novel opportunities and potential for the treatment of diseases associated with an impaired endothelium. This review discusses therapies currently available for the treatment of these disorders and highlights the application of nanomedicine for the therapy of these major disease complications.

Drug delivery interfaces in the 21st century: from science fiction ideas to viable technologies

Early science fiction envisioned the future of drug delivery as targeted micrometer-scale submarines and "cyborg" body parts. Here we describe the progression of the field toward technologies that are now beginning to capture aspects of this early vision. Specifically, we focus on the two most prominent types of systems in drug delivery: the intravascular micro/nano drug carriers for delivery to the site of pathology and drug-loaded implantable devices that facilitate release with the predefined kinetics or in response to a specific cue. We discuss the unmet clinical needs that inspire these designs, the physiological factors that pose difficult challenges for their realization, and viable technologies that promise robust solutions. We also offer a perspective on where drug delivery may be in the next 50 years based on expected advances in material engineering and in the context of future diagnostics.

Gold nanoparticle as a marker for precise localization of nano-objects within intracellular sub-domains

Delivery of nano-objects to certain intracellular sub-domains is crucial for nanomedicine. Therefore delivery of nano-object to desirable cellular compartment has to be confirmed. The most valuable confirmation of the delivery comes from direct visualization of the nano-object. This visualization usually requires use of microscope and corresponding probe which has to be conjugated with the nano-object. There are two most popular methods of the visualization: confocal and electron microscopy. The former has significant limitations due to diffraction limited resolution of confocal systems and three-dimensional convolution of fluorescence. The latter should be significantly modified for needs of the visualization. Here we describe the method for precise localization of nano-object within the cell using electron microscopy and 1-2 nm gold particles as a nanomarker.

Permeabilization of cell membrane for delivery of nano-objects to cellular sub-domains

Delivery of nano-objects to specific cellular sub-domains is a challenging but intriguing task. There are two major barriers on the way of a nano-object to its intracellular target: (1) the cell membrane and (2) the intracellular barriers. The former is a common issue for all nanomedicine and a matter of very intense research. The latter is the primary problem for targeted delivery of nano-objects to specific cellular sub-domains and can be studied more easily using permeabilized cells. Membrane permeabilization for nanomedical research requires (1) perforation of the outer membrane, (2) development of a solution that will keep cellular sub-domains in the functional state, and (3) modification of the perimembrane cytoskeleton. We developed a very successful model of saponin membrane permeabilization of cardiomyocytes. This allowed us to deliver particles up to 20 nm in size to perinuclear and perimitochondrial space. Here we describe the method.

Emerging applications of nanomedicine for the diagnosis and treatment of cardiovascular diseases

Nanomedicine is an emerging field that utilizes nanotechnology concepts for advanced therapy and diagnostics. This convergent discipline merges research areas such as chemistry, biology, physics, mathematics and engineering. It therefore bridges the gap between molecular and cellular interactions, and has the potential to revolutionize medicine. This review presents recent developments in nanomedicine research poised to have an important impact on the treatment of cardiovascular disease. This will occur through improvement of the diagnosis and therapy of cardiovascular disorders as atherosclerosis, restenosis and myocardial infarction. Specifically, we discuss the use of nanoparticles for molecular imaging and advanced therapeutics, specially designed drug eluting stents and in vivo/ex vivo early detection techniques.

Mitochondria in cardiomyocyte Ca2+ signaling

Ca(2+) signaling is of vital importance to cardiac cell function and plays an important role in heart failure. It is based on sarcolemmal, sarcoplasmic reticulum and mitochondrial Ca(2+) cycling. While the first two are well characterized, the latter remains unclear, controversial and technically challenging. In mammalian cardiac myocytes, Ca(2+) influx through L-type calcium channels in the sarcolemmal membrane triggers Ca(2+) release from the nearby junctional sarcoplasmic reticulum to produce Ca(2+) sparks. When this triggering is synchronized by the cardiac action potential, a global [Ca(2+)](i) transient arises from coordinated Ca(2+) release events. The ends of intermyofibrillar mitochondria are located within 20 nm of the junctional sarcoplasmic reticulum and thereby experience a high local [Ca(2+)] during the Ca(2+) release process. Both local and global Ca(2+) signals may thus influence calcium signaling in mitochondria and, reciprocally, mitochondria may contribute to the local control of calcium signaling. In addition to the intermyofibrillar mitochondria, morphologically distinct mitochondria are also located in the perinuclear and subsarcolemmal regions of the cardiomyocyte and thus experience a different local [Ca(2+)]. Here we review the literature in regard to several issues of broad interest: (1) the ultrastructural basis for mitochondrion - sarcoplasmic reticulum cross-signaling; (2) mechanisms of sarcoplasmic reticulum signaling; (3) mitochondrial calcium signaling; and (4) the possible interplay of calcium signaling between the sarcoplasmic reticulum and adjacent mitochondria. Finally, this review discusses experimental findings and mathematical models of cardiac calcium signaling between the sarcoplasmic reticulum and mitochondria, identifies weaknesses in these models, and suggests strategies and approaches for future investigations.