CRS 2026 Annual Meeting and Exposition Conference Recap

Key themes from CRS 2026

• Next-generation ionizable lipids dominated the conference. Researchers presented numerous new lipid designs to improve potency, reduce immunogenicity and enable delivery beyond the liver, highlighting the central role of ionizable lipids in future LNP development.
• The search for replacements for PEG-lipids and ethanol is intensifying. Researchers presented strategies to develop PEG-free alternatives, while one study identified organic solvent selection as another promising — yet largely unexplored — parameter for enhancing LNP performance. Results shown were interesting, but many limitations remain and the path looks long for clinically viable replacements.
• Understanding intracellular delivery is becoming as important as achieving it. New tools such as Lysosomal Barcoding (LysoBC) now enable direct quantification of endosomal escape in vivo, while several studies showed that successful endosomal escape does not necessarily translate into productive cytosolic protein expression.
• Extrahepatic delivery is increasingly being guided by a mechanism-based design. Lung-, lymph node- and immune-cell-targeted LNPs illustrated how lipid structure, surface chemistry and biological pathways can be engineered to direct nanoparticles toward specific tissues.
• The manufacturing process is increasingly recognized as a determinant of LNP performance. Several presentations mentioned that formulation techniques can alter Lipid Nanoparticle composition, critical quality attributes (CQAs) and bio–nano interactions. Despite growing interest, the impact of manufacturing processes on LNP quality and function remains underexplored.
• Seamless scale-up remains one of the field’s biggest unresolved challenges. Current microfluidic approaches struggle with scale-up, whereas turbulent mixers present the opposite challenge: developing scale-down that reproduce equivalent mixing conditions.

Selected presentation highlights from CRS 2026

Among the many outstanding presentations at CRS 2026, we selected a few that were particularly relevant to our work in RNA-LNP formulation, manufacturing, and translational nanomedicine. The talks below highlight advances in delivery science, formulation design, intracellular delivery, and scalable manufacturing, while also illustrating the challenges that continue to shape the future of RNA therapeutics.

The Evolution of mRNA LNPs: From Vaccines to Targeted Therapeutics and Genome Editing (Daniel G. Anderson, Massachusetts Institute of Technology, USA)

Prof. Daniel Anderson presented a broad overview of how LNP technology has evolved from enabling the first nucleic acid therapeutics to supporting increasingly sophisticated applications, including targeted RNA delivery, genome editing, and next-generation RNA modalities.

• The presentation traced the development of lipid-based nucleic acid delivery from early cationic lipids, such as DOTMA, to modern ionizable lipid nanoparticles, emphasizing how advances in lipid chemistry have dramatically improved the potency and safety of RNA therapeutics.
• A major focus was the rational design of next-generation ionizable lipids. Combinatorial lipid synthesis, coupled with high-throughput screening, has enabled the discovery of increasingly potent lipid structures capable of achieving therapeutic effects at substantially lower doses than earlier formulations.
• Prof. Anderson highlighted how artificial intelligence and large structure–function datasets could transform LNP development. He introduced the Lipid Nanoparticle Database (LNPDB) which compiles formulation composition together with biological performance data, creating a foundation for machine learning-guided optimization of nanoparticle design and tissue targeting. [1]

• The presentation also highlighted the growing potential of LNPs to enable in vivo CRISPR therapies for diseases including transthyretin (TTR) amyloidosis [2], hypercholesterolemia (PCSK9), and sickle cell disease. Particular emphasis was placed on overcoming challenges associated with the co-delivery of Cas9 mRNA and guide RNA, including chemical stabilization of guide RNAs to improve editing efficiency. [3]
• Recent advances in targeted LNPs were showcased, including CD117-targeted nanoparticles capable of delivering RNA directly to hematopoietic stem cells (HSCs) in vivo, opening possibilities for genome editing without ex vivo cell manipulation. [4]
• Finally, the presentation explored the growing interest in circular RNA (circRNA) therapeutics. Owing to their closed molecular structure, circRNAs exhibit improved stability and prolonged protein expression compared with conventional mRNA, making them attractive candidates for next-generation RNA medicines. Early preclinical studies demonstrated targeted circRNA delivery to immune cells, including T cells and NK cells, highlighting the expanding therapeutic potential of this platform.

The presentation illustrated how the field is rapidly progressing beyond conventional mRNA vaccines toward programmable, tissue-targeted delivery platforms that integrate advanced lipid chemistry, computational design, and genome editing technologies to enable increasingly precise RNA therapeutics.

Cell-Specific Targeting: Technological and Biological Considerations (Dan Peer, Tel Aviv University, Israel)

Prof. Dan Peer presented recent advances in cell-specific LNP delivery, emphasizing how targeted RNA therapeutics are expanding beyond the liver toward diverse cell types and disease applications. The talk covered the development of delivery platforms for siRNA, mRNA, CRISPR/Cas9 genome editing, and circular RNA (circRNA), while highlighting the technological, manufacturing, and biological challenges that remain.

• The presentation highlighted how RNA therapeutics can be designed to silence, activate, edit, or replace genes, depending on the therapeutic objective, using different RNA modalities including siRNA, mRNA, CRISPR/Cas9, and emerging circRNA technologies.
• A major focus was the development of next-generation ionizable lipids, with Prof. Peer describing the synthesis and screening of more than 50,000 lipid structures to identify formulations with improved delivery efficiency while minimizing immune activation and toxicity.
• The importance of manufacturing and analytical quality control was emphasized. Small variations during formulation — including seemingly minor parameters such as the quality of water used during production — can significantly influence LNP properties. Improved analytical methods are also needed to characterize formulations, including empty particles and structural variability within same LNP preparations.
• Examples of LNP-based infectious disease vaccines demonstrated the versatility of the platform beyond COVID-19. Preclinical studies showed that a single-dose mRNA-LNP vaccine provided complete protection against bubonic plague following subcutaneous administration [5] and robust protection against pneumonic plague following intranasal challenge across multiple mouse strains. [6]
• Considerable attention was given to targeting strategies, comparing different approaches for functionalized LNPs, including one-step assembly, post-formulation chemical conjugation, and post-insertion techniques. The presentation emphasized that antibody orientation on the nanoparticle surface is critical for efficient receptor binding and discussed the use of the ASSET/LAND platform to achieve controlled antibody orientation and receptor-specific targeting. [7]

• In the context of genome editing, the presentation discussed the challenges of co-delivering Cas9 mRNA (~4600 bp) and guide RNAs (~120 bp), emphasizing that highly stable chemically modified guide RNAs are critical for achieving efficient CRISPR-mediated gene editing. Both knockout and knock-in strategies were presented as potential approaches for treating diseases such as cancer.
• Emerging circular RNA (circRNA) therapeutics were presented as a promising next-generation RNA platform owing to their enhanced stability, prolonged protein expression, reduced innate immune activation, and simplified manufacturing, since they do not require conventional capping or polyadenylation. Potential applications include protein replacement therapies, miRNA/protein sponges, and immune modulation.
• The presentation concluded by outlining several remaining challenges for the field: (1) efficient extrahepatic targeting, overcoming the liver tropism of LNPs, (2) enhancing endosomal escape, (3) reducing immunogenicity during repeat dosing, (4) understanding cargo and LNP co-dependency, and (5) translating preclinical findings into human studies. These challenges can be summarized as key priorities for the continued development of cell-specific RNA delivery systems.

Mechanistic Insight on Trafficking In Vivo (Gaurav Sahay, Oregon State University)

Prof. Gaurav Sahay presented recent advances in understanding the intracellular trafficking of LNPs, with a particular focus on quantifying endosomal escape in vivo. Although endosomal escape is widely recognized as the principal bottleneck for nucleic acid delivery, its kinetics and regulatory mechanisms still remain difficult to study in living organisms. His group developed a library of bioinspired branched ionizable phospholipids, identifying BiP-20 as a highly potent liver-targeting LNP that substantially outperformed current benchmark formulations. To investigate why BiP-20 exhibits enhanced delivery, they established Lysosomal Barcoding (LysoBC), a first-in-class method that enables direct quantification of endosomal escape in vivo using LysoTag mice. Combining this platform with genetic perturbation and lysosomal proteomics provided new mechanistic insight into the endosomal pathways governing LNP trafficking and cytosolic release. [8]

• LNP uptake into hepatocytes occurs predominantly through ApoE-mediated binding to LDL receptors, driving efficient liver-specific endocytosis.
• Rational engineering of bioinspired branched ionizable lipids demonstrated that lipid geometry (e.g., cylindrical versus conical structures) can be optimized to enhance endosomal membrane disruption and cytosolic delivery.
• The lead formulation, BiP-20, showed markedly improved liver delivery and significantly outperformed the clinical benchmark LP-01, achieving approximately eightfold higher CRISPR-Cas9 editing efficiency of the TTR gene at low doses.
• Existing approaches for measuring endosomal escape, such as the Galectin-8 (Gal8) recruitment assay, provide only indirect estimates and are not readily applicable in vivo, highlighting the need for more quantitative methodologies.
• The newly developed Lysosomal Barcoding (LysoBC) platform enables direct measurement of endosomal escape by isolating lysosomes from LysoTag mice and quantifying barcode molecules that remain trapped versus those released into the cytosol. Using this approach, approximately 8% of BiP-20 LNPs escaped within 30 minutes of administration, confirming that productive escape occurs rapidly after uptake.

• Genetic disruption of endosomal maturation revealed that Rab7-mediated late endosomal maturation is a major barrier to escape. Liver-specific Rab7 knockout significantly increased endosomal escape, whereas Rab5a depletion had minimal effect, indicating that escape primarily occurs during the transition from early to late endosomes.
• Electron microscopy demonstrated that Rab7 deficiency produced enlarged endosomal compartments, suggesting that increased membrane surface area and prolonged residence time enhance opportunities for LNP membrane fusion and cargo release.
• Quantitative proteomic analysis of isolated lysosomes identified approximately 2,000 lysosomal proteins and showed that both Rab7 deletion and BiP-20 treatment extensively remodel proteins involved in endosomal maturation, recycling, and lysosomal function, providing mechanistic insight into intracellular trafficking pathways that regulate delivery efficiency.
• Overall, this work introduced the first quantitative in vivo platform for measuring endosomal escape kinetics and established a liver-specific Rab7 knockout model to investigate endosomal maturation. The findings demonstrated that endosomal escape occurs rapidly — the most productive release taking place within 30 minutes — and that blocking late endosome biogenesis enhances escape efficiency, likely by generating enlarged early/early-late endosomes with increased membrane surface area and residence time for membrane fusion. In addition, LNP treatment was shown to extensively remodel lysosomal protein composition, providing new mechanistic insight into the intracellular pathways governing RNA delivery.
• Future work will extend these mechanistic studies beyond the liver and investigate how disease states alter endosomal trafficking and therapeutic delivery.

Further discussions from CRS 2026

• Multiplexed LNP barcoding is accelerating the study of functional biodistribution. Prof. Daniel Siegwart presented a Cre recombinase mRNA barcode platform that allows multiple LNP formulations to be pooled and assessed simultaneously in vivo. The work demonstrated that early biodistribution measurements may correlate more closely with functional tropism than later time points and revealed differences in delivery across hepatic metabolic zones.
• Cytosolic release does not necessarily guarantee productive translation. Dr. Fanfei Meng proposed that post-endosomal dissociation of mRNA from LNP components may be an additional bottleneck after escape. Reducing the ionizable-lipid fraction weakened lipid–RNA interactions and improved transfection, while salt-loaded LNPs used osmotic pressure to enhance escape. Together, these findings suggest that next-generation formulations must balance cargo protection, endosomal release and subsequent RNA availability for translation.
• The manufacturing process can change the LNP composition, nanoparticle attributes, and bio-nano interactions. Dr. Thomas L. Moore showed that different preparation methods — including benchtop mixing, T-junction mixing and hydrodynamic flow focusing — produced differences in final lipid composition even when starting from the same nominal formulation. Microfluidic production appeared to enrich the ionizable lipid component, with corresponding effects on biological activity. The results reinforced that manufacturing method should be treated as a critical formulation variable rather than a neutral processing step.
• Reducing LNP immunogenicity may unlock broader therapeutic use. Prof. Niren Murthy presented switchable nanoparticles (SNPs) that are negatively charged at physiological pH but become positively charged under acidic conditions. These particles delivered mRNA while avoiding several inflammatory mechanisms associated with conventional ionizable lipids, including TLR4, complement, galectin-8 and platelet-activating-factor pathways.
• Organic solvent selection may be an underexplored lever for improving LNP performance. Dr. Koki Ogawa presented a systematic screen of water-miscible organic solvents and identified pyridine as a promising alternative to ethanol. Pyridine-prepared LNPs showed high monodispersity and improved mRNA expression in vitro and potentially in vivo, while displaying comparable toxicity after appropriate purification. The underlying mechanism remains unclear, but the findings highlight how organic solvent type may influence nanoparticle assembly and biological function.
• Surface polymers are being redesigned to replace or complement PEG. Poly(acrylamido) lipids (Dr. Benjamin M. Fiedler) and alternative hydrophilic polymers were explored as ways to improve immune cell transfection, redirect biodistribution and evade anti-PEG antibodies. However, the detection of antibodies against some replacement polymers indicated that alternatives must also be assessed carefully for repeat-dose immunogenicity rather than assumed to be immunologically inert.
• Protein-corona engineering could provide a new route to precision targeting. Prof. Chunying Chen described active manipulation of nanoparticle surface chemistry to enrich selected endogenous proteins and control cellular uptake, circulation and organ distribution. This represents a shift from passive observation of the corona toward deliberate programming of the biological identity acquired by nanoparticles in vivo.
• Extrahepatic delivery strategies are becoming more rationally designed. Lung-selective dual-pKa ionizable lipid-based LNPs (MSc. Seong Gi Lim), lymph-node-tropic LNPs of which surface is modified with DSPE-anionic polymer conjugates (Dr. Muhammad Muzamil Khan), and disulfide-bond-containing ionizable lipid-based LNPs for macrophage delivery illustrated how protonation, lipid structure, protein-corona composition and intracellular redox conditions can be exploited to enhance functional delivery outside the liver.

References

[1]       E. Collins et al., “Lipid Nanoparticle Database towards structure-function modeling and data-driven design for nucleic acid delivery,” Nature Communications , vol. 17, no. 1, Dec. 2026, doi: 10.1038/s41467-026-68818-1.

[2]       J. D. Gillmore et al., “CRISPR-Cas9 In Vivo Gene Editing for Transthyretin Amyloidosis,” New England Journal of Medicine, vol. 385, no. 6, pp. 493–502, Aug. 2021, doi: 10.1056/nejmoa2107454.

[3]       H. Yin et al., “structure-guided chemical modification of guide RNA enables potent non-viral in vivo genome editing,” Nat. Biotechnol., vol. 35, no. 12, pp. 1179–1187, 2017, doi: 10.1038/nbt.4005.

[4]       D. Shi, S. Toyonaga, and D. G. Anderson, “In Vivo RNA Delivery to Hematopoietic Stem and Progenitor Cells via Targeted Lipid Nanoparticles,” Nano Lett., vol. 23, no. 7, pp. 2938–2944, Apr. 2023, doi: 10.1021/acs.nanolett.3c00304.

[5]       E. Kon et al., “A P P L I E D S C I E N C E S A N D E N G I N E E R I N G A single-dose F1-based mRNA-LNP vaccine provides protection against the lethal plague bacterium,” 2023. [Online]. Available: https://www.science.org

[6]       U. Elia et al., “Novel Bivalent mRNA-LNP Vaccine for Highly Effective Protection against Pneumonic Plague,” Advanced Science, vol. 12, no. 26, Jul. 2025, doi: 10.1002/advs.202501286.

[7]       D. Tarab-Ravski et al., “The future of genetic medicines delivered via targeted lipid nanoparticles to leukocytes,” Journal of Controlled Release, vol. 376, pp. 286–302, Dec. 2024, doi: 10.1016/j.jconrel.2024.10.014.

[8]       A. Jozić et al., “In vivo endosomal escape assay identifies mechanisms for efficient hepatic LNP delivery,” Nature Biotechnology 2026, pp. 1–11, Mar. 2026, doi: 10.1038/s41587-026-03022-6.