Abdulrahman, A. | Search bioRxiv

bioRxiv2025

Intravenous lipid-siRNA conjugate mediates gene silencing at the blood-brain barrier and blood-CSF barrier

Barriers of the central nervous system (CNS), such as the blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BCSFB), regulate the two-way exchange of material between the blood and CNS. These barriers pose a considerable challenge for efficacious delivery of intravenously administered therapies into the CNS, motivating exploration of their function and ways to modulate their properties. While the BBB and BCSFB can become dysfunctional in patients with chronic CNS diseases, few studies have focused on strategies for targeting these interfaces. Here, we showed that an intravenously administered albumin-binding lipid-siRNA conjugate was delivered to and silences genes within brain endothelial cells and choroid plexus epithelial cells, which comprise the BBB and BCSFB, respectively. A single intravenous dose of lipid-siRNA conjugate was delivered to [~]100% of brain endothelial cells and major choroid plexus cell types, without any substantial delivery into brain parenchymal tissue. Sustained gene silencing was achieved in both brain endothelial cells (over two weeks) and bulk choroid plexus tissues (up to one month). Moreover, single cell RNA sequencing demonstrated gene knockdown in capillaries, venous endothelial cells, and choroid plexus epithelial cells without silencing genes in parenchymal cell populations. Collectively, this work establishes an effective nonviral framework to mediate gene inhibition in the brain barriers. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=156 SRC="FIGDIR/small/642142v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@b00a52org.highwire.dtl.DTLVardef@175a363org.highwire.dtl.DTLVardef@39be75org.highwire.dtl.DTLVardef@1072093_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2024

Lipid-siRNA conjugate accesses a perivascular transport mechanism and achieves widespread and durable knockdown in the central nervous system

Short-interfering RNA (siRNA) has gained significant interest for treatment of neurological diseases by providing the capacity to achieve sustained inhibition of nearly any gene target. Yet, efficacious drug delivery throughout deep brain structures of the CNS remains a considerable hurdle for intrathecally administered therapeutics. We herein describe an albumin-binding lipid-siRNA conjugate that transports along meningeal and perivascular CSF pathways, leading to broad dispersion throughout the CNS parenchyma. We provide a detailed examination of the temporal kinetics of gene silencing, highlighting potent knockdown for up to five months from a single injection without detectable toxicity. Single-cell RNA sequencing further demonstrates gene silencing activity across diverse cell populations in the parenchyma and at brain borders, which may provide new avenues for neurological disease-modifying therapies.

bioengineering↗