Abstract
Lipid nanoparticle (LNP) delivery of RNA therapeutics is constrained by poor tissue selectivity and off-target toxicity. Most high-throughput screening approaches have focused on single-target efficacy while overlooking off-target uptake. Here we report multiobjective LNP engineering with artificial intelligence (MOLEA), a system that integrates high-dimensional lipid representations, cell-type-resolved transfection data and multitask optimization to design ionizable lipids with both high potency and biological selectivity. MOLEA learns structure–function relationships across diverse cellular contexts to identify lipids that preferentially deliver mRNA to target tissue while minimizing hepatocyte transfection. Applying MOLEA to cartilage, we developed K9 LNPs, which achieve >90% transfection efficiency in mouse joint chondrocytes and a 13.5-fold increase in knee-to-liver selectivity compared to the clinical benchmark SM-102. We demonstrate chondrocyte-specific Mmp13 editing in osteoarthritis mouse models, leading to sustained cartilage protection and suppression of disease-associated immune and matrix remodeling. Our findings demonstrate how artificial-intelligence-guided multiobjective optimization can enable precision RNA delivery with potential applications to other tissues.
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Data availability
All data are available in the main text or Supplementary Information. Sequencing data from amplicon NGS experiments were deposited to the National Center for Biotechnology Information Sequence Read Archive under BioProject PRJNA1440167. Source data are provided with this paper.
Code availability
The codebase data and code used in this study are available from the GitHub (https://github.com/bowenli-lab/MOLEA) and Zenodo (https://doi.org/10.5281/zenodo.18943783)58 repositories with the MIT license.
References
Polack, F. P. et al. Safety and efficacy of the BNT162b2 mRNA COVID-19 vaccine. N. Engl. J. Med. 383, 2603–2615 (2020).
Baden, L. R. et al. Efficacy and safety of the mRNA-1273 SARS-CoV-2 vaccine. N. Engl. J. Med. 384, 403–416 (2021).
Adams, D. et al. Patisiran, an RNAi therapeutic, for hereditary transthyretin amyloidosis. N. Engl. J. Med. 379, 11–21 (2018).
Nasreen, S. et al. Effectiveness of COVID-19 vaccines against symptomatic SARS-CoV-2 infection and severe outcomes with variants of concern in Ontario. Nat. Microbiol. 7, 379–385 (2022).
Hou, X., Zaks, T., Langer, R. & Dong, Y. Lipid nanoparticles for mRNA delivery. Nat. Rev. Mater. 6, 1078–1094 (2021).
Vasileva, O., Zaborova, O., Shmykov, B., Ivanov, R. & Reshetnikov, V. Composition of lipid nanoparticles for targeted delivery: application to mRNA therapeutics. Front. Pharmacol. 15, 1466337 (2024).
Wittrup, A. et al. Visualizing lipid-formulated siRNA release from endosomes and target gene knockdown. Nat. Biotechnol. 33, 870–876 (2015).
Kim, M. et al. Engineered ionizable lipid nanoparticles for targeted delivery of RNA therapeutics into different types of cells in the liver. Sci. Adv. 7, eabf4398 (2021).
Qiu, M. et al. Lung-selective mRNA delivery of synthetic lipid nanoparticles for the treatment of pulmonary lymphangioleiomyomatosis. Proc. Natl Acad. Sci. USA 119, e2116271119 (2022).
Hosseini-Kharat, M., Bremmell, K. E. & Prestidge, C. A. Why do lipid nanoparticles target the liver? Understanding of biodistribution and liver-specific tropism. Mol. Ther. Methods Clin. Dev. 33, 101436 (2025).
Akinc, A. et al. Targeted delivery of RNAi therapeutics with endogenous and exogenous ligand-based mechanisms. Mol. Ther. 18, 1357–1364 (2010).
Jain, R. et al. MicroRNAs enable mRNA therapeutics to selectively program cancer cells to self-destruct. Nucleic Acid Ther. 28, 285–296 (2018).
Ramishetti, S. et al. A combinatorial library of lipid nanoparticles for RNA delivery to leukocytes. Adv. Mater. 32, e1906128 (2020).
Chen, J. et al. Combinatorial design of ionizable lipid nanoparticles for muscle-selective mRNA delivery with minimized off-target effects. Proc. Natl Acad. Sci. USA 120, e2309472120 (2023).
Li, B. et al. Combinatorial design of nanoparticles for pulmonary mRNA delivery and genome editing. Nat. Biotechnol. 41, 1410–1415 (2023).
Han, X. et al. In situ combinatorial synthesis of degradable branched lipidoids for systemic delivery of mRNA therapeutics and gene editors. Nat. Commun. 15, 1762 (2024).
Peña, Á et al. Multicomponent thiolactone-based ionizable lipid screening platform for efficient and tunable mRNA delivery to the lungs. Commun. Chem. 8, 116 (2025).
Isaac, I. et al. Tetrahydropyrimidine ionizable lipids for efficient mRNA delivery. ACS Nano 18, 29045–29058 (2024).
Hamilton, A. G. et al. High-throughput in vivo screening identifies differential influences on mRNA lipid nanoparticle immune cell delivery by administration route. ACS Nano 18, 16151–16165 (2024).
Kauffman, K. J. et al. Optimization of lipid nanoparticle formulations for mRNA delivery in vivo with fractional factorial and definitive screening designs. Nano Lett. 15, 7300–7306 (2015).
Ly, H. H., Daniel, S., Soriano, S. K. V., Kis, Z. & Blakney, A. K. Optimization of lipid nanoparticles for saRNA expression and cellular activation using a design-of-experiment approach. Mol. Pharm. 19, 1892–1905 (2022).
Su, K. et al. Reformulating lipid nanoparticles for organ-targeted mRNA accumulation and translation. Nat. Commun. 15, 5659 (2024).
Wang, C. et al. Blood–brain-barrier-crossing lipid nanoparticles for mRNA delivery to the central nervous system. Nat. Mater. 24, 1653–1663 (2025).
Yamankurt, G. et al. Exploration of the nanomedicine-design space with high-throughput screening and machine learning. Nat. Biomed. Eng. 3, 318–327 (2019).
Xu, Y. et al. LUMI-lab: a foundation model-driven autonomous platform enabling discovery of ionizable lipid designs for mRNA delivery. Cell 189, 1620–1635 (2026).
Xu, Y. et al. AGILE platform: a deep learning powered approach to accelerate LNP development for mRNA delivery. Nat. Commun. 15, 6305 (2024).
Wang, W. et al. Artificial intelligence-driven rational design of ionizable lipids for mRNA delivery. Nat. Commun. 15, 10804 (2024).
Witten, J. et al. Artificial intelligence-guided design of lipid nanoparticles for pulmonary gene therapy. Nat. Biotechnol. 43, 1790–1799 (2025).
Li, B. et al. Accelerating ionizable lipid discovery for mRNA delivery using machine learning and combinatorial chemistry. Nat. Mater. 23, 1002–1008 (2024).
Sengprasert, P., Kamenkit, O., Tanavalee, A. & Reantragoon, R. The immunological facets of chondrocytes in osteoarthritis: a narrative review. J. Rheumatol. 51, 13–24 (2024).
Aigner, T., Söder, S., Gebhard, P. M., McAlinden, A. & Haag, J. Mechanisms of disease: role of chondrocytes in the pathogenesis of osteoarthritis–structure, chaos and senescence. Nat. Clin. Pract. Rheumatol. 3, 391–399 (2007).
Zheng, L., Zhang, Z., Sheng, P. & Mobasheri, A. The role of metabolism in chondrocyte dysfunction and the progression of osteoarthritis. Ageing Res. Rev. 66, 101249 (2021).
Madry, H. & Trippel, S. B. Efficient lipid-mediated gene transfer to articular chondrocytes. Gene Ther. 7, 286–291 (2000).
Hamm, A., Krott, N., Breibach, I., Blindt, R. & Bosserhoff, A. K. Efficient transfection method for primary cells. Tissue Eng. 8, 235–245 (2002).
Li, X., Shen, L., Deng, Z. & Huang, Z. New treatment for osteoarthritis: gene therapy. Precis. Clin. Med. 6, pbad014 (2023).
Wang, Y., Wang, J., Cao, Z. & Barati Farimani, A. Molecular contrastive learning of representations via graph neural networks. Nat. Mach. Intell. 4, 279–287 (2022).
Moriwaki, H., Tian, Y.-S., Kawashita, N. & Takagi, T. Mordred: a molecular descriptor calculator. J. Cheminform. 10, 4 (2018).
McInnes, L., Healy, J., Saul, N. & Großberger, L. UMAP: uniform manifold approximation and projection. J. Open Source Softw. 3, 861 (2018).
Schwab, W. et al. Characterization of caveolins from human knee joint cartilage: expression of caveolin-1, -2, and -3 in chondrocytes and association with integrin β1. Histochem. Cell Biol. 113, 221–225 (2000).
Wang, P., Zhu, F., Tong, Z. & Konstantopoulos, K. Response of chondrocytes to shear stress: antagonistic effects of the binding partners Toll-like receptor 4 and caveolin-1. FASEB J. 25, 3401–3415 (2011).
Guan, F. et al. Tissue macrophages: origin, heterogenity, biological functions, diseases and therapeutic targets. Signal Transduct. Target. Ther. 10, 93 (2025).
Gustafson, H. H., Holt-Casper, D., Grainger, D. W. & Ghandehari, H. Nanoparticle UPTAKE: THE PHAGOCYTE PROBLEM. Nano Today 10, 487–510 (2015).
Madisen, L. et al. A robust and high-throughput Cre reporting and characterization system for the whole mouse brain. Nat. Neurosci. 13, 133–140 (2010).
Staahl, B. T. et al. Efficient genome editing in the mouse brain by local delivery of engineered Cas9 ribonucleoprotein complexes. Nat. Biotechnol. 35, 431–434 (2017).
Finn, J. D. et al. A single administration of CRISPR/Cas9 lipid nanoparticles achieves robust and persistent in vivo genome editing. Cell Rep. 22, 2227–2235 (2018).
Yu, S. Y. et al. A luciferase reporter mouse model to optimize in vivo gene editing validated by lipid nanoparticle delivery of adenine base editors. Mol. Ther. 31, 1159–1166 (2023).
Bedingfield, S. K. et al. Amelioration of post-traumatic osteoarthritis via nanoparticle depots delivering small interfering RNA to damaged cartilage. Nat. Biomed. Eng. 5, 1069–1083 (2021).
Colazo, J. M. et al. siRNA conjugate with high albumin affinity and degradation resistance for delivery and treatment of arthritis in mice and guinea pigs. Nat. Biomed. Eng. 9, 1366–1383 (2025).
Bedingfield, S. K. et al. Top-down fabricated microPlates for prolonged, intra-articular matrix metalloproteinase 13 siRNA nanocarrier delivery to reduce post-traumatic osteoarthritis. ACS Nano 15, 14475–14491 (2021).
Hu, Q. & Ecker, M. Overview of MMP-13 as a promising target for the treatment of osteoarthritis. Int. J. Mol. Sci. 22, 1742 (2021).
Wang, M. et al. MMP13 is a critical target gene during the progression of osteoarthritis. Arthritis Res. Ther. 15, R5 (2013).
Takaishi, H., Kimura, T., Dalal, S., Okada, Y. & D’Armiento, J. Joint diseases and matrix metalloproteinases: a role for MMP-13. Curr. Pharm. Biotechnol. 9, 47–54 (2008).
Zenhausern, R. et al. Lipid nanoparticle screening in nonhuman primates with minimal loss of life. Nat. Biotechnol. https://doi.org/10.1038/s41587-025-02711-y (2025).
Kim, H. et al. Lipid nanoparticle-mediated mRNA delivery to CD34+ cells in rhesus monkeys. Nat. Biotechnol. 43, 1813–1820 (2025).
Charni-Natan, M. & Goldstein, I. Protocol for primary mouse hepatocyte isolation. STAR Protoc. 1, 100086 (2020).
Gosset, M., Berenbaum, F., Thirion, S. & Jacques, C. Primary culture and phenotyping of murine chondrocytes. Nat. Protoc. 3, 1253–1260 (2008).
Saeki, N. & Imai, Y. Isolation and culture of primary synovial macrophages and fibroblasts from murine arthritis tissue. J. Vis. Exp. 192, e65196 (2023).
Li, B. & Li, G. bowenli-lab/MOLEA: v1.0.0. Zenodo https://doi.org/10.5281/zenodo.18943783 (2026).
Acknowledgements
This research was funded by the Accelerate Translation grant from the Acceleration Consortium (518240), the GSK Chair Professorship, the startup fund from the Leslie Dan Faculty of Pharmacy, the operating fund from the Princess Margaret Cancer Center, the Connaught Fund (514681), the J.P. Bickell Foundation (515159), the Canada Research Chairs Program (CRC-2022-00575), the Canadian Institutes of Health Research (CIHR; PJH-185722, PJT-192011 and PJT-195669), the Natural Sciences and Engineering Research Council of Canada (RGPIN-2023-05124), the National Institutes of Health (1R01HL174773) and the Canada Foundation for Innovation John R. Evans Leaders Fund (43711). This research was made possible in part through computing resources provided by Calcul Québec (https://www.calculquebec.ca/) and the Digital Research Alliance of Canada (https://www.alliancecan.ca). Jingan Chen acknowledges the doctoral-level graduate award from the NanoMedicines Innovation Network. M.S. acknowledges the support from the CIHR Canada Graduate Scholarship Master’s (CGS-M) program. B.S. acknowledges the support from the Ontario Graduate Scholarship. T.T. acknowledges the support from the Ontario Graduate Scholarship. D.C. acknowledges the support from the CIHR CGS-M program. We acknowledge the technical support from the Center for Pharmaceutical Oncology in Flow Cytometry and Imaging Facilities, the Princess Margaret Cancer Center for the use of NMR and animal facilities and the Donnelly Sequencing Center. Illustrations in figures were created in BioRender; Li, B. https://biorender.com/z0nhgnn (2026).
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M.Z. and B.L. conceptualized the study and designed the overall experimental framework. M.Z. and Y.X. developed the combinatorial lipid library. M.Z. and G.L. determined the methodological approach. M.Z., Y.X., G.L., Jingan Chen, B.S., F.G., T.T., Juan Chen, R.X.Z.L., S.D., D.C., C.E., S.W. and G.Z. conducted the experiments and performed the data analysis. B.L., M.Z. and M.S. wrote the paper. B.L. secured funding and supervised the project.
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Extended data
Extended Data Fig. 1 K9 LNP enables therapeutic genome editing in a DMM-induced osteoarthritis model.
a, Schematic of the dosing schedule in the destabilization of the medial meniscus (DMM) surgical model. Mice received either a single dose or two weekly intra-articular injections of K9 LNPs (total RNA dose: 5 μg/joint; mCas9:sgMMP-13 = 3:1), starting two months after DMM surgery. Tissues were collected for analysis four months after the final dose for analysis. b, Editing efficiency at the MMP13 locus in knee joints and liver, assessed by sequencing (n = 3 biologically independent mice per group; mean ± SD; P values were calculated by ordinary one-way ANOVA). c-d, Quantification of MMP-13 expression in the knee joint by (c) ELISA (n = 4 biologically independent mice per group; mean ± SD; P values were calculated by ordinary one-way ANOVA). and (d) RT-qPCR (n = 3 biologically independent mice per group; each sample was measured in duplicate; mean ± SD; P values were calculated by ordinary one-way ANOVA). e-f, Mechanism of the MMPSense probe and representative in vivo images showing total MMP activity with varying LNP doses (e), and the quantification result (f). Blue circles represent the area of quantified fluorescence. (n = 3 biologically independent mice per group; mean ± SD; P values were calculated by ordinary one-way ANOVA). g-h, Detection of MMP-13 protein in cartilage by (g) fluorescence imaging and (h) corresponding quantification. (n = 6 biologically independent mice per group; mean ± SD; P values were calculated by ordinary one-way ANOVA). Scale bar, 100 μm. i-j, (i) SHG imaging of articular cartilage and (j) quantification of cartilage thickness and organization. (n = 3 biologically independent mice per group; mean ± SD; P values were calculated by ordinary one-way ANOVA). k, Representative histological images of knee joints from sham control, untreated, and K9-treated DMM mice stained with Safranin O and TRAP; magnified insets highlight cartilage and osteoclast features. Healthy cartilage appears deep red due to Safranin O staining of proteoglycans, while TRAP staining highlights osteoclasts in red. Scale bar, 100 μm. l-m, Osteoarthritis severity assessed using OARSI scoring (l) and quantification of osteoclast numbers from TRAP-stained sections (m) (n = 5 biologically independent mice per group; mean ± SD; P values were calculated by ordinary one-way ANOVA). n, Representative microCT 3D reconstructions of knee joints from sham, untreated, and K9-treated DMM mice, shown in frontal (left) and posterior (right) views with magnified insets below. Red arrows highlight areas of disrupted joint architecture, ectopic ossification, and osteophyte formation. o, Quantification of trabecular bone volume fraction (BV/TV, %) from microCT scans, indicating changes in subchondral bone density across treatment groups. (n = 3 biologically independent mice per group; mean ± SD; P values were calculated by ordinary one-way ANOVA).
Extended Data Fig. 2 Proteomic analysis of DMM mouse model post-K9 LNP treatment.
a, Volcano plot showing protein expression changes in knee joints following two doses of K9 LNP (mCas9 + sgTOM) treatment, as identified by LC-MS/MS. Significantly altered proteins are highlighted in red, identified using a two-sided Student’s t-test with Benjamini-Hochberg false discovery rate (FDR) correction in Spectronaut, and visualized as a volcano plot using the SRplot platform. b, KEGG pathway enrichment analysis of differentially expressed proteins between treated and untreated groups. c-h, GO enrichment analysis of differentially expressed proteins, displayed as cnetplots and bubble plots for (c, d) biological processes, (e, f) molecular functions, and (g, h) cellular components. i, j, Gene set enrichment analysis (GSEA) plots showing enriched pathways in DMM mice with or without K9 LNP treatment. KEGG and GO enrichment analyses were performed using two-sided hypergeometric tests with Benjamini-Hochberg FDR correction for multiple testing.
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Zhou, M., Xu, Y., Li, G. et al. A multiobjective AI model for LNP engineering enhances tissue-selective mRNA delivery. Nat Biotechnol (2026). https://doi.org/10.1038/s41587-026-03109-0
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DOI: https://doi.org/10.1038/s41587-026-03109-0


