Exosomes, bilipid layer nano-particles (~50-150nm), are generated by nearly all cells and mediate intercellular communication. MicroRNAs are non-coding RNAs contained within exosomes that post-transcriptionally and concurrently regulate translation of a multiplicity of genes. Here, I will briefly describe our preclinical work harnessing exosomes from a variety of cells to acutely and subacutely treat stroke and neural injury and will demonstrate the therapeutic effects of this nanoparticle therapy in promoting neurovascular remodeling and neurological recovery. I will also describe means to enhance the treatment of neurological disease and injury by employing exosomes engineered to be enriched with selective miRNAs. These "designer" exosomes are designed with the miRNA content tailored to specifically enhance the therapeutic neurovascular protective and restorative effects of exosome treatment for a targeted disease, whether stroke, traumatic brain injury, dementia or peripheral neuropathy. Since exosomes mediate intercellular communication our ability to regulate and alter intercellular and inter-organ interaction via exosomes provide a powerful potential therapy for many diseases.