Heparin-derived theranostic nanoprobes overcome the blood-brain barrier and target glioma in murine model
The poor permeability of theranostic agents across the blood-brain-barrier (BBB) significantly hampers the development of new treatment modalities for neurological diseases. We have discovered a new biomimetic nanocarrier using heparin (HP) that effectively passes the BBB and targets glioblastoma. Specifically, we designed HP coated gold nanoparticles (HP-AuNPs) that were labeled with three different imaging modalities namely, fluorescein (FITC-HP-AuNP), radioisotope 68Gallium (68Ga-HP-AuNPs), and MRI active gadolinium (Gd-HP-AuNPs). The systemic infusion of FITC-HP-AuNPs in three different mouse strains (C57BL/6JRj, FVB, and NMRI-nude) displayed excellent penetration and revealed uniform distribution of fluorescent particles in the brain parenchyma (69-86%) with some accumulation in neurons (8-18%) and microglia (4-10%). Tail-vein administration of radiolabeled 68Ga-HP-AuNPs in healthy rats also showed 68Ga-HP-AuNP inside the brain parenchyma and in areas containing cerebrospinal fluid, such as the lateral ventricles, the cerebellum, and brain stem. Finally, tail-vein administration of Gd-HP-AuNPs (that display [~]3 fold higher relaxivity than that of commercial Gd-DTPA) in an orthotopic glioblastoma (U87MG xenograft) model in nude mice demonstrated enrichment of T1-contrast at the intracranial tumor with a gradual increase in the contrast in the tumor region between 1h-3h. We believe, our finding offers the untapped potential of HP-derived-NPs to deliver cargo molecules for treating neurological disorders.