Disclosed are capsid-modified rAAV expression vectors, as well as infectious virions, compositions, and pharmaceutical formulations that include them. Also disclosed are methods of preparing and using novel capsid-protein-mutated rAAV vector constructs in a variety of diagnostic and therapeutic applications including, inter alia, as delivery agents for diagnosis, treatment, or amelioration of one or more diseases, disorders, or dysfunctions of the mammalian vascular system, and complications from Type I diabetes. Also disclosed are methods for systemic and tissue-localized delivery of therapeutic rAAV-based gene expression cassettes to vascular endothelial cells, tissues, and organs, as well as use of the disclosed compositions in the manufacture of medicaments for a variety of in vitro and/or in vivo applications including the treatment of vasculitis, and complications arising from Type I diabetes, such as macular edema, nephropathy, diabetic retinopathy, and the like.