Ischemic stroke causes vascular and neuronal tissue deficiencies that could lead to substantial functional impairment and/or death. Although progenitor-based vasculogenic cell therapies have shown promise as a potential rescue strategy following ischemic stroke, current approaches face major hurdles. Here, we used fibroblasts nanotransfected with Etv2, Foxc2, and Fli1 (EFF) to drive reprogramming-based vasculogenesis, intracranially, as a potential therapy for ischemic stroke. Perfusion analyses suggest that intracranial delivery of EFF-nanotransfected fibroblasts led to a dose-dependent increase in perfusion 14 days after injection. MRI and behavioral tests revealed ~70% infarct resolution and up to ~90% motor recovery for mice treated with EFF-nanotransfected fibroblasts. Immunohistological analysis confirmed increases in vascularity and neuronal cellularity, as well as reduced glial scar formation in response to treatment with EFF-nanotransfected fibroblasts. Together, our results suggest that vasculogenic cell therapies based on nanotransfection-driven (i.e., nonviral) cellular reprogramming represent a promising strategy for the treatment of ischemic stroke.

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Gene/oligonucleotide therapies have emerged as a promising strategy for the treatment of different neurological conditions. However, current methodologies for the delivery of neurogenic/neurotrophic cargo to brain and nerve tissue are fraught with caveats, including reliance on viral vectors, potential toxicity, and immune/inflammatory responses. Moreover, delivery to the central nervous system is further compounded by the low permeability of the blood brain barrier. Extracellular vesicles (EVs) have emerged as promising delivery vehicles for neurogenic/neurotrophic therapies, overcoming many of the limitations mentioned above. However, the manufacturing processes used for therapeutic EVs remain poorly understood. Here, we conducted a detailed study of the manufacturing process of neurogenic EVs by characterizing the nature of cargo and surface decoration, as well as the transfer dynamics across donor cells, EVs, and recipient cells. Neurogenic EVs loaded with Ascl1, Brn2, and Myt1l (ABM) are found to show enhanced neuron-specific tropism, modulate electrophysiological activity in neuronal cultures, and drive pro-neurogenic conversions/reprogramming. Moreover, murine studies demonstrate that surface decoration with glutamate receptors appears to mediate enhanced EV delivery to the brain. Altogether, the results indicate that ABM-loaded designer EVs can be a promising platform nanotechnology to drive pro-neuronal responses, and that surface functionalization with glutamate receptors can facilitate the deployment of EVs to the brain.

Acute respiratory distress syndrome (ARDS) represents a significant burden to the healthcare system, with ≈200 000 cases diagnosed annually in the USA. ARDS patients suffer from severe refractory hypoxemia, alveolar‐capillary barrier dysfunction, impaired surfactant function, and abnormal upregulation of inflammatory pathways that lead to intensive care unit admission, prolonged hospitalization, and increased disability‐adjusted life years. Currently, there is no cure or FDA‐approved therapy for ARDS. This work describes the implementation of engineered extracellular vesicle (eEV)‐based nanocarriers for targeted nonviral delivery of anti‐inflammatory payloads to the inflamed/injured lung. The results show the ability of surfactant protein A (SPA)‐functionalized IL‐4‐ and IL‐10‐loaded eEVs to promote intrapulmonary retention and reduce inflammation, both in vitro and in vivo. Significant attenuation is observed in tissue damage, proinflammatory cytokine secretion, macrophage activation, influx of protein‐rich fluid, and neutrophil infiltration into the alveolar space as early as 6 h post‐eEVs treatment. Additionally, metabolomics analyses show that eEV treatment causes significant changes in the metabolic profile of inflamed lungs, driving the secretion of key anti‐inflammatory metabolites. Altogether, these results establish the potential of eEVs derived from dermal fibroblasts to reduce inflammation, tissue damage, and the prevalence/progression of injury during ARDS via nonviral delivery of anti‐inflammatory genes/transcripts.

Vasculogenic cell therapies have emerged as a powerful tool to increase vascularization and promote tissue repair/regeneration. Current approaches to cell therapies, however, rely mostly on progenitor cells, which pose significant risks (e.g., uncontrolled differentiation, tumorigenesis, and genetic/epigenetic abnormalities). Moreover, reprogramming methodologies used to generate induced endothelial cells (iECs) from induced pluripotent stem cells rely heavily on viral vectors, which pose additional translational limitations. This work describes the development of engineered human extracellular vesicles (EVs) capable of driving reprogramming-based vasculogenic therapies without the need for progenitor cells and/or viral vectors. EVs are derived from primary human dermal fibroblasts (HDFs), and are engineered to pack transcription factor genes/transcripts of ETV2, FLI1, and FOXC2 (EFF). In addition to EFF, the engineered EVs are also loaded with transcripts of angiogenic factors (e.g., VEGF-A, VEGF-KDR, FGF2). In vitro and in vivo studies indicate that such EVs effectively transfected HDFs and drive direct conversions towards iECs within 714 days. Finally, wound healing studies in mice indicate that engineered EVs lead to improved wound closure and vascularity. Altogether, these results show the potential of engineered human vasculogenic EVs to drive direct reprogramming processes of somatic cells towards iECs, and facilitate tissue repair/regeneration.

Functionalized Extracellular Vesicles In article number 2100805 by Natalia Higuita‐Castro and co‐workers, designer extracellular vesicles (EVs) are manufactured via non‐viral engineering of donor cells through electroporation. Designer EVs are packed with plasmid DNA, mRNA, and protein content. Transfecting donor cells with expression plasmids for membrane proteins can be used to tailor the surface decoration of the EVs. Pro‐neurogenic designer EVs drive neurogenesis and improve targeting of neuronal tissue, in vitro and in vivo.

Globally, age-related macular degeneration (AMD) is the third most common visual impairment. Most often attributed to cellular fatigue with aging, over expression of reactive oxygen species (ROS) accummulates in the...

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