In eukaryotic cells, mitochondrial dysfunction is associated with a variety of human diseases. Delivery of exogenous functional mitochondria into damaged cells has been proposed as a mechanism of cell transplant and physiological repair for damaged tissue. We here demonstrated that isolated mitochondria can be transferred into homogeneic and xenogeneic cells by simple co‐incubation using genetically labelled mitochondria, and elucidated the mechanism and the effect of direct mitochondrial transfer. Intracellular localization of exogenous mitochondria was confirmed by PCR, real‐time PCR, live fluorescence imaging, three‐dimensional reconstruction imaging, continuous time‐lapse microscopic observation, flow cytometric analysis and immunoelectron microscopy. Isolated homogeneic mitochondria were transferred into human uterine endometrial gland‐derived mesenchymal cells in a dose‐dependent manner. Moreover, mitochondrial transfer rescued the mitochondrial respiratory function and improved the cellular viability in mitochondrial DNA‐depleted cells and these effects lasted several days. Finally, we discovered that mitochondrial internalization involves macropinocytosis. In conclusion, these data support direct transfer of exogenous mitochondria as a promising approach for the treatment of various diseases.

The Impella microaxial-flow pump can directly unload left ventricle (LV) in cases of acute heart failure. Extracorporeal membrane oxygenation (ECMO) is widely used for circulatory support. Although the clinical effectiveness of ECMO has been demonstrated, insufficient LV loading reduction may not be advantageous for myocardial recovery. The objective was to compare ventricular loading reduction and reversibility of ventricular fibrillation (VF) with either Impella or ECMO. Six dogs were used. Extracorporeal membrane oxygenation was established by the femoral artery and right atrium. The Impella LD was inserted in LV by the ascending aorta. An acute failing heart was created by sequential coronary artery ligations. Pressure-volume (PV) relationships were acquired without a device and with ECMO or Impella. When VF occurred, direct cardioversion was performed while supported by either ECMO or Impella. The PV area, which is a measure of ventricular unloading and is correlated with myocardial oxygen consumption, decreased more with Impella than with ECMO. Successful defibrillation was achieved more effectively while under Impella support. Superior ventricular unloading with the Impella device may provide higher recovery potential to damaged hearts than ECMO and may have a significant impact not only on intensive care of patients with heart failure but also on resuscitation.

Nanoparticle technology is being incorporated into many areas of molecular science and biomedicine. Because nanoparticles are small enough to enter almost all areas of the body, including the circulatory system and cells, they have been and continue to be exploited for basic biomedical research as well as clinical diagnostic and therapeutic applications. For example, nanoparticles hold great promise for enabling gene therapy to reach its full potential by facilitating targeted delivery of DNA into tissues and cells. Substantial progress has been made in binding DNA to nanoparticles and controlling the behavior of these complexes. In this article, we review research on binding DNAs to nanoparticles as well as our latest study on non-viral gene delivery using polyethylenimine-coated magnetic nanoparticles.