Ad-El, N. | bioRxiv Science

bioRxiv2025

Low-frequency ultrasound-mediated blood-brain barrier opening enables non-invasive lipid nanoparticle RNA delivery to glioblastoma

Ionizable Lipid Nanoparticles (LNPs) are an FDA-approved non-viral RNA delivery system, though their use for brain therapy is restricted by the blood-brain barrier (BBB). Focused ultrasound combined with microbubbles can disrupt the BBB, but delivering large particles requires balancing increased peak negative pressures while maintaining microvascular integrity. Herein, we optimized low-frequency ultrasound parameters to induce high-amplitude microbubble oscillations, enabling the safe delivery of LNPs across the BBB. First, BBB opening was assessed at different frequencies (850, 250, and 80 kHz) and pressures by monitoring the extravasation of Evans blue (~1 kDa). Next, the delivery of 4, 70, and 150 kDa Dextrans, LNPs entrapping Cy5-siRNAs (~70 nm in diameter), and LNPs entrapping mRNA (~100 nm in diameter) was evaluated via microscopy and bioluminescence. In a glioblastoma syngeneic mouse model, siRNA-Cy5-LNP was successfully delivered. A frequency of 850 kHz and 125 kPa pressure induced safe BBB opening, enabling delivery of both small molecules and LNPs. In healthy brains, LNP entrapping siRNAs delivery increased 10-fold compared to controls, and LNPs with mRNAs showed a 12-fold increase in bioluminescence after 24 hours. In glioblastoma tumors, LNPs with siRNAs delivery resulted in a 6.7-fold increase in fluorescence. This study paves the way for non-invasive LNP delivery to the brain, offering a versatile platform for brain therapies. TOC graphic O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=76 SRC="FIGDIR/small/634427v1_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@cad2bdorg.highwire.dtl.DTLVardef@1d1936corg.highwire.dtl.DTLVardef@259d83org.highwire.dtl.DTLVardef@1883aed_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2022

An Effective mRNA-LNP Vaccine Against the Lethal Plague Bacterium

Plague is a rapidly deteriorating contagious disease that has killed millions of people during the history of mankind and is caused by the gram-negative bacterium Yersinia pestis. Currently, the disease is treated effectively with antibiotics. However, in the case of an outbreak caused by a multiple-antibiotic-resistant strain, alternative countermeasures are required. Despite the many efforts to develop a safe vaccine against the disease, there is still no vaccine approved for use in western countries. mRNA Lipid Nanoparticle (mRNA-LNP) vaccines have been demonstrated during the Covid-19 pandemic to be a versatile, clinically relevant, and rapidly manufactured vaccine platform. However, harnessing this platform for bacterial pathogens remains a formidable challenge. Here, we describe the design of several mRNA-LNP vaccine versions against Y. pestis, based on the F1 capsular antigen. We demonstrate that mRNA-LNP vaccines encoding the F1 antigen with either no signal sequences or conjugated to human Fc, provide substantial cellular and humoral responses. Most importantly, these vaccine candidates fully protect animals against Y. pestis infection. The results of this study suggest that mRNA-LNPs can be effective as anti-bacterial vaccines, and further developed to combat other bacterial pathogens, which are urgently needed, given the looming threat of antibiotic resistance. One-Sentence SummaryA novel mRNA-LNP vaccine against Y. pestis, the etiological agent of plague and the first documented mRNA-LNP vaccine to protect against a lethal bacterial pathogen infection.

microbiology↗