Biology subjects

Muzykantov, V.

Publications and source records attributed to Muzykantov, V..

4 recordsLinked to original sources

bioRxiv2024

Marginated neutrophils in the lungs effectively compete for nanoparticles targeted to the endothelium, serving as a part of the reticuloendothelial system

Nanomedicine has long pursued the goal of targeted delivery to specific organs and cell types but has not achieved this goal with the vast majority of targets. One rare example of success in this pursuit has been the 25+ years of studies targeting the lung endothelium using nanoparticles conjugated to antibodies against endothelial surface molecules. However, here we show that such "endothelial-targeted" nanocarriers also effectively target the lungs numerous marginated neutrophils, which reside in the pulmonary capillaries and patrol for pathogens. We show that marginated neutrophils uptake of many of these "endothelial-targeted" nanocarriers is on par with endothelial uptake. This generalizes across diverse nanomaterials and targeting moieties and was even found with physicochemical lung tropism (i.e., without targeting moieties). Further, we observed this in ex vivo human lungs and in vivo healthy mice, with an increase in marginated neutrophil uptake of nanoparticles caused by local or distant inflammation. These findings have implications for nanomedicine development for lung diseases. These data also suggest that marginated neutrophils, especially in the lungs, should be considered a major part of the reticuloendothelial system (RES), with a special role in clearing nanoparticles that adhere to the lumenal surfaces of blood vessels. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=172 SRC="FIGDIR/small/597904v1_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@17e0518org.highwire.dtl.DTLVardef@809eb6org.highwire.dtl.DTLVardef@33d9a7org.highwire.dtl.DTLVardef@169863_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2024

Lipid Nanoparticle-Associated Inflammation is Triggered by Sensing of Endosomal Damage: Engineering Endosomal Escape without Side Effects

Lipid nanoparticles (LNPs) have emerged as the dominant platform for RNA delivery, based on their success in the COVID-19 vaccines and late-stage clinical studies in other indications. However, we and others have shown that LNPs induce severe inflammation, and massively aggravate pre-existing inflammation. Here, using structure-function screening of lipids and analyses of signaling pathways, we elucidate the mechanisms of LNP-associated inflammation and demonstrate solutions. We show that LNPs hallmark feature, endosomal escape, which is necessary for RNA expression, also directly triggers inflammation by causing endosomal membrane damage. Large, irreparable, endosomal holes are recognized by cytosolic proteins called galectins, which bind to sugars on the inner endosomal membrane and then regulate downstream inflammation. We find that inhibition of galectins abrogates LNP-associated inflammation, both in vitro and in vivo. We show that rapidly biodegradable ionizable lipids can preferentially create endosomal holes that are smaller in size and reparable by the endosomal sorting complex required for transport (ESCRT) pathway. Ionizable lipids producing such ESCRT-recruiting endosomal holes can produce high expression from cargo mRNA with minimal inflammation. Finally, we show that both routes to non-inflammatory LNPs, either galectin inhibition or ESCRT-recruiting ionizable lipids, are compatible with therapeutic mRNAs that ameliorate inflammation in disease models. LNPs without galectin inhibition or biodegradable ionizable lipids lead to severe exacerbation of inflammation in these models. In summary, endosomal escape induces endosomal membrane damage that can lead to inflammation. However, the inflammation can be controlled by inhibiting galectins (large hole detectors) or by using biodegradable lipids, which create smaller holes that are reparable by the ESCRT pathway. These strategies should lead to generally safer LNPs that can be used to treat inflammatory diseases.

bioengineering↗

bioRxiv2023

A combination of physicochemical tropism and affinity moiety targeting of lipid nanoparticles enhances organ targeting

Two camps have emerged in the targeting of nanoparticles to specific organs and cell types: affinity moiety targeting, which conjugates nanoparticles to antibodies or similar molecules that bind to known surface markers on cells; and physicochemical tropism, which achieves specific organ uptake based on the nanoparticles physical or chemical features (e.g., binding to endogenous proteins). Because these camps are largely non-overlapping, the two targeting approaches have not been directly compared or combined. Here we do both, using intravenous (IV) lipid nanoparticles (LNPs) whose original design goal was targeting to the lungs endothelial cells. For an affinity moiety, we utilized PECAM antibodies, and for physicochemical tropism, we used cationic lipids, both having been heavily studied for lung targeting. Surprisingly, the two methods yield nearly identical levels of lung uptake. However, aPECAM LNPs display much greater specificity for endothelial cells. Intriguingly, LNPs that possess both targeting methods had >2-fold higher lung uptake than either method alone. The combined-targeting LNPs also achieved greater uptake in already inflamed lungs, and greater uptake in alveolar epithelial cells. To understand how the macro-scale route of delivery affects organ targeting, we compared IV injection vs. intra-arterial (IA) injection into the carotid artery. We found that IA combined-targeting LNPs achieve 35% of the injected dose per gram (%ID/g) in the brain, a level superior to any other reported targeting method. Thus, combining affinity moiety targeting and physicochemical tropism provides benefits that neither targeting method achieves alone. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=56 SRC="FIGDIR/small/568061v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@281d31org.highwire.dtl.DTLVardef@1948026org.highwire.dtl.DTLVardef@693f99org.highwire.dtl.DTLVardef@1ce74cb_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2023

Physicochemical Targeting of Lipid Nanoparticles to the Lungs Induces Clotting: Mechanisms and Solutions

Lipid nanoparticles (LNPs) have become the dominant drug delivery technology in industry, holding the promise to deliver RNA to up- or down-regulate any protein of interest. LNPs have been targeted to specific cell types or organs by physicochemical targeting, in which LNPs lipid compositions are adjusted to find mixtures with the desired tropism. In a popular approach, physicochemical targeting is accomplished by formulating with charged lipids. Negatively charged lipids localize LNPs to the spleen, and positively charged lipids to the lungs. Here we found that lung-tropic LNPs employing cationic lipids induce massive thrombosis. We demonstrate that thrombosis is induced in the lungs and other organs, and greatly exacerbated by pre-existing inflammation. This clotting is induced by a variety of formulations with cationic lipids, including LNPs and non-LNP nanoparticles. The mechanism depends on the LNPs binding to fibrinogen and inducing platelet and thrombin activation. Based on these mechanisms, we engineered multiple solutions which enable positively charged LNPs to target the lungs while not inducing thrombosis. Our findings implicate thrombosis as a major barrier that blood erects against LNPs with cationic components and illustrate how physicochemical targeting approaches must be investigated early for risks and re-engineered with a careful understanding of biological mechanisms.

bioengineering↗