Further, peptide-NBs prepared with a hybrid insulin peptide (HIP) expanded islet HIP-reactive regulatory T cells and substantially delayed diabetes onset in an adoptive transfer mouse model of autoimmune diabetes.<h4>Conclusions</h4>Peptide-NBs offer a promising 'theranostic' approach for induction of peripheral tolerance in T1D while monitoring delivery and action via ultrasound contrast. Here, INS is linked to type 1 diabetes mellitus.