Intravenous gene delivery via cationic lipidic vectors gives in this study. Yet, vectors of different lipid compositions systemic gene expression particularly in the lung. In order vary greatly in the rate of disintegration. There is an inverse to understand the mechanism of intravenous lipofection, a correlation between the disintegration rate of lipidic vectors systematic study was performed to investigate the interacand their in vivo transfection efficiency. Vectors with a rapid tions of lipidic vectors with mouse serum emphasizing how rate of disintegration such as those containing dioleoylserum affects the biophysical and biological properties of phosphatidylethanolamine (DOPE) poorly stayed in the vectors of different lipid compositions. Results from this lung and were barely active in transfecting cells. In constudy showed that lipidic vectors underwent dynamic trast, cholesterol-containing vectors that had a rapid aggrechanges in their characteristics after exposure to serum.gation and a slow disintegration were highly efficient in Addition of lipidic vectors into serum resulted in an immeditransfecting cells in vivo. The results of this study explain ate aggregation of vectors. Prolonged incubation of lipidic why cationic lipidic vectors of different lipid compositions vectors with serum led to vector disintegration as shown in have a dramatic difference in their in vivo transfection turbidity study, sucrose-gradient centrifugation analysis efficiency. These results also suggest that the study of the and fluorescence resonance energy transfer (FRET) study.interactions of lipidic vectors with serum may serve as a Vector disintegration was associated with DNA release and predictive model for the in vivo efficiency of a lipidic vector. degradation as shown in EtBr intercalation assay and DNA Further study of the numerous interactions of lipidic vectors digestion study. Serum-induced disintegration of vectors is with serum might lead to the development of a vector which a general phenomenon for all cationic lipidic vectors tested can deliver a gene to target cells in a tissue-specific manner.

Ischemic stroke causes brain endothelial cell death and damages tight junction integrity of the blood-brain barrier (BBB). We engineered endothelial cell-derived extracellular vesicles (EVs) for the delivery of exogenous heat shock protein 27 (HSP27) and harnessed the innate EV mitochondrial load as a one, two-punch strategy to increase brain endothelial cell survival (via mitochondrial delivery) and preserve their tight junction integrity (via HSP27 delivery). We demonstrated that endothelial microvesicles but not exosomes transferred their mitochondrial load that subsequently underwent fusion with the mitochondrial network of the recipient primary human brain endothelial cells. This mitochondrial transfer increased the relative ATP levels and mitochondrial function in the recipient endothelial cells. EV-mediated HSP27 delivery to primary human brain endothelial cells decreased the paracellular permeability of small and large molecular mass fluorescent tracers in an in vitro model of ischemia/reperfusion injury. This one, two-punch approach to increase the metabolic function and structural integrity of brain endothelial cells is a promising strategy for BBB protection and prevention of long-term neurological dysfunction post-ischemic stroke.Highlights➢Exosomes and microvesicles (EVs) can be engineered for co-delivery of bio-actives➢Microvesicles (MV) but not exosomes contain functional mitochondria➢MV mitochondria fused with the mitochondria in recipient brain endothelial cells➢MVs increase mitochondrial function while EVs increase cellular ATP levels➢EV-mediated HSP27 delivery decreased dextran permeability in brain endothelial cellsGraphical Abstract

The extensive crosstalk between the developing heart and lung is pivotal for their proper morphogenesis and maturation. However, there remains a lack of model systems for investigating the critical cardio-pulmonary mutual interaction during human embryogenesis. Here, we reported a novel stepwise strategy for directing simultaneous induction of both mesoderm-derived cardiac and endoderm-derived lung epithelial lineages within a single differentiation of human pluripotent stem cells (hPSCs) via temporal specific tuning of WNT and TGF-β signaling in the absence of exogenous growth factors. Using 3D suspension culture, we established concentric cardio-pulmonary micro-Tissues (μTs), and observed expedited alveolar maturation in the presence of cardiac accompany. Upon withdrawal of WNT agonist, the cardiac and pulmonary components within each dual-lineage μT effectively segregated from each other with concurrent initiation of cardiac contraction. We expect our multilineage differentiation model to offer an experimentally tractable system for investigating human cardio-pulmonary interplay and tissue boundary formation during embryogenesis.