XH-04 (Lipid#4)​​ is an ionizable lipid engineered for advanced mRNA delivery developed by ​​JiaChen West Lake Biotech. Its core structure features a central benzene ring with asymmetric hydrophobic tails (C9-C10 chains) and pH-responsive tertiary amines that enable efficient mRNA encapsulation and endosomal escape. As detailed in CN113993839A, XH04 outperforms industry benchmarks (e.g., MC3 lipid), boosting protein expression by ​​>10-fold​​ in BHK cells. In PCT/CN2024/121624, JiaChen further demonstrated its utility in lung-targeted LNPs (tLNP/tLCNP). When combined with cationic lipids (e.g., DOTMA at 2:1 molar ratio), XH 04 redirects >80% of mRNA delivery to murine lungs—overcoming liver tropism—while maintaining low toxicity. The lipid’s benzenic core and optimized alkyl chain geometry (patent claims 1-9) are credited for enhanced endosomal disruption and mRNA release kinetics. JiaChen’s innovations position XH-04 as a cornerstone for next-generation mRNA therapeutics.

IAJD-34 is a one-component ionizable amphiphilic Janus dendrimer specifically engineered for targeted mRNA delivery to the lung parenchyma, as described by Meshanni et al. in Nature Communications article "Targeted delivery of TGF-β mRNA to murine lung parenchyma using one-component ionizable amphiphilic Janus Dendrimers" . This synthetic nanoparticle self-assembles with mRNA through simple mixing in acetate buffer, forming stable dendrimersomes approximately 93-97 nm in size with high encapsulation efficiency (>95%) and a positive zeta potential (~48 mV). Its defining feature, highlighted in the study, is exceptional lung tropism after intravenous injection, enabling significantly higher luciferase expression in murine lungs compared to other organs. As demonstrated by Meshanni et al., IAJD 34 effectively delivers therapeutic mRNA (e.g., TGF-β mRNA) to the lower lung, inducing transient protein production with minimal systemic toxicity at appropriate doses (e.g., 10 µg), offering a promising strategy for treating parenchymal lung diseases.

Si5-N14 is a lipid-based molecule engineered with siloxane groups, designed specifically for efficient mRNA delivery to the lungs. The incorporation of siloxane units boosts the cellular uptake of mRNA-loaded lipid nanoparticles (LNPs) and enhances their ability to escape from endosomes. These properties significantly increase the overall effectiveness of mRNA delivery, making Si5-N14 a promising tool for targeted therapeutic applications.

5A2-SC8 is a dendrimer for miRNA delivery to late-stage liver tumors with low hepatotoxicity. 5A2-SC8 shows potent EC50 < 0.02 mg/kg (siRNA against FVII (siFVII)) in dose-response experiments, and well tolerated in separate toxicity studies in chronically ill mice bearing MYC-driven tumors. 5A2-SC8 is a degradable lipid-like compound (ester-based dendrimer) for small RNAs delivery.5A2-SC8, was obtained by screening a large library of more than 1500 ester-based dendrimers containing ionizable amino groups, which have three tertiary amine heads and five lipid tails. Based on this library, the in vitro transfection efficiency of different formulations of 5A2-SC8 iLNPs was evaluated, discovering the optimal formulation (5A2-SC8, DOPE, cholesterol, PEG at a molar ratio of 15:15:30:3) of 5A2-SC8 iLNPs for delivering fumarylacetoacetate hydrolase (FAH) mRNA to liver.After the intravenous injection via tail, the model mice of hepatorenal tyrosinemia type I had strong FAH protein expression, which prevented body weight loss and increased the survival rate of hepatorenal tyrosinemia mice . In addition to introducing utility of 5A2-SC8 iLNPs for the therapeutic intervention, the 5A2-SC8 iLNPs containing DOTAP have been used to establish complex mouse models via intravenous injection, including in situ liverspecific cancer model and in situ lung-specific cancer model. Based on this iLNPs delivery system, 5A2-SC8 induced model construction method overcomes the time-consuming and costly disadvantages of traditional animal models establishing methods, including transgenesis and gene engineering in embryonic stem cells.

Lipid 331 is a biodegradable cyclic ionizable lipid. LNPs containing Lipid 331 result in robust transfection in the nasal and lung tissues of mice and efficient transfection of lung epithelial cells and lung-resident APCs. Lipid 331 is a promising candidate for mRNA vaccine delivery, offering the potential for further enhancing the potency of mRNA vaccines.

RCB-4-8​​ is a biodegradable ionizable lipid nanoparticle (LNP) engineered for efficient pulmonary mRNA delivery and in vivo genome editing, as detailed in the primary research article ​​"Combinatorial design of nanoparticles for pulmonary mRNA delivery and genome editing"​​ (Li et al., Nature Biotechnology 2023）. Synthesized from a combinatorial library of 720 biodegradable lipids via a three-component reaction system, RCB-4-8 features an alkyne-containing lipid tail and tertiary amine headgroup, optimized through high-throughput screening for superior lung-targeting capabilities. Its unique molecular design incorporates hydrolyzable ester and carbonate groups, enabling rapid biodegradation (<30% lung retention at 48 h vs. >90% for conventional lipids) while maintaining high transfection efficiency. When formulated with DOTAP instead of DOPE, RCB-4-8 LNPs achieved ​​100-fold higher luciferase mRNA expression​​ in murine lungs compared to FDA-approved MC3 LNPs and mediated ​​95% GFP knockout​​ in vitro. In Ai9 reporter mice, intratracheal delivery of RCB-4-8 loaded with Cre mRNA edited ​​53% of total lung cells​​ after three doses, while codelivery with Cas9 mRNA/sgRNA yielded ​​7.2% tdTomato⁺ cells​​, rising to ​​17%​​ when combined with AAV-sgRNAs. With an optimal particle size of ​​85.7 nm​​ (PDI 0.11) and ​​>87% mRNA encapsulation​​, RCB-4-8 supports repeat dosing and represents a transformative platform for inhalable gene therapies targeting congenital lung diseases like cystic fibrosis.

4A3-SC7​​ is a proprietary, ionizable lipid component central to the SORT LNP platform developed for targeted organ delivery. It features a unique ​​branched-tail structure​​ designed to enhance mRNA encapsulation and endosomal escape. In the study, it served as the ​​primary ionizable lipid​​ in both Liver SORT LNPs and updated Lung SORT LNPs. For liver targeting, it was formulated at ​​15.04 mol%​​ alongside helper lipids (DOPE: 23.04%, Cholesterol: 38.72%), PEG-lipid (DMG-PEG2000: 3.2%), and the liver-targeting lipid ​​4A3-Cit (20 mol%)​​. This specific composition (Total lipid:RNA = 20:1 wt/wt) yielded LNPs with ​​~74 nm size​​, ​​low PDI (0.17)​​, and ​​high encapsulation efficiency (87%)​​ for large mRNAs like ABE editors (~5000 nt). Its branched-tail architecture was critical for stabilizing nanoparticles encapsulating large RNAs, overcoming a key limitation of previous formulations. 4A3-SC7-based Liver SORT LNPs enabled ​​>40% base editing in hepatocytes​​ in vivo, achieving durable correction of the disease-causing SERPINA1 mutation in PiZ mice and significantly reducing pathological protein aggregates. In the updated DualSORT system, 4A3-SC7 was also paired with ​​DORI​​ (instead of DOTAP) for improved lung targeting, demonstrating its versatility as a foundational ionizable lipid for multi-organ gene editing therapeutics.

The LUMI-6 lipid, autonomously designed via the LUMI-lab platform, is a brominated ionizable lipid optimized for mRNA delivery. Formulated at a molar ratio of 35:28:34.5:2 (LUMI-6:DOTAP:cholesterol:C14-PEG2000), LNPs exhibit uniform physicochemical properties, including a hydrodynamic diameter of ~80 nm, polydispersity index (PDI) <0.2, and robust mRNA encapsulation efficiency. In vitro, LUMI-6 LNPs demonstrated 1.8-fold higher transfection potency in human bronchial epithelial cells compared to its debrominated counterpart (LUMI-6D), with minimal cytotoxicity confirmed by CCK-8 assays. In vivo, pulmonary delivery of CRISPR-Cas9 mRNA via LUMI-6 LNPs achieved ​20.3% gene editing efficiency in murine lung epithelial cells, surpassing SM-102 (Moderna’s clinical benchmark) and demonstrating ​preferential tropism for lung epithelium over endothelial cells—critical for inhaled therapies targeting cystic fibrosis and surfactant disorders. The brominated tail enhances endosomal escape through optimized protonation dynamics, though explicit pKa values remain unmeasured. Synthesized via high-throughput combinatorial chemistry and refined through AI-driven active learning, LUMI-6 combines scalable production with organ-selective delivery, positioning it as a transformative platform for pulmonary nucleic acid therapeutics.

6Ac1-C12 is an ester-core degradable ionizable cationic lipid designed for mRNA delivery, featuring a unique hexa-acrylate ester core ("6Ac1") conjugated with six N-methyldodecylamine chains ("C12") via solvent-free Michael addition. This branched architecture enables optimal mRNA encapsulation and confers exceptional stability, maintaining consistent ~100 nm particle size for over 30 days at 4°C—crucial for cold-chain storage. With a pKa ≈ 6.0, it facilitates pH-responsive endosomal escape through membrane fusion (80% FRET signal increase at pH 5.5) and efficient cytoplasmic mRNA release.Its composition allows precise organ targeting: in conventional four-component LNPs, 98% hepatic mRNA expression occurs post-IV administration, primarily in endothelial cells (60% transfection efficiency). Cholesterol removal enables lung-specific accumulation and translation via three-component formulations, overcoming historical hepatic off-targeting. The lipid shows negligible cytotoxicity in vitro (>85% cell viability) and no significant organ damage in vivo (ALT/AST/BUN/CREA levels comparable to PBS controls). Its degradable ester core hydrolyzes into smaller metabolites, enhancing biocompatibility. Modular compatibility with DOTAP/DDAB cationic lipids expands applicability for pulmonary or splenic targeting, establishing 6Ac1-C12 as a versatile platform for organ-selective mRNA therapeutics.

Lipid 119-23 is an ionizable lipid for mRNA delivery. 119-23 LNP exhibits an enhanced capability to express functional mCre in several categories of immune cells, spanning the liver, spleen and lung.

(+)CP-LC-0729 is an cationic lipid derived from CP-LC-0729 and achieves significantly higher expression and selectivity highlights the advantages of this lipid system for lung-targeted delivery.

FO-32 is an artificial intelligence-guided designed ionizable lipid for RNA delivery to the muscle, lung and nose. FO-32 LNPs enable potent transfection throughout the whole ferret lung epithelium, from trachea to alveoli.

PPz-2R1 is an ionizable cationic lipid engineered for mRNA delivery via lipid nanoparticles (LNPs). These LNPs demonstrate remarkable lung-selective accumulation in mice, showing significantly higher uptake compared to heart, liver, spleen, and kidney tissues. When loaded with PTEN mRNA, PPz-2R1 LNPs effectively restore tumor suppressor function in PTEN-deficient lung cancer cells and inhibit tumor progression in orthotopic models, with enhanced efficacy observed in combination with PD-1 blockade therapy.

FO35 is an artificial intelligence-guided designed ionizable lipid for RNA delivery to the muscle, lung and nose. FO-35 LNPs enable potent transfection throughout the whole ferret lung epithelium, from trachea to alveoli.

306-N16B is a lipidnanoparticle, and allows systemic codelivery of Cas9 mRNA and sgRNA. 306-N16B can transport mRNA to the pulmonaryendothelial cell. 306-N16B can be used for research of genome editing-based therapies. Based on the same lipid libraries with 306-O12B, the researchers also found that N-series ionizable lipids were able to selectively deliver mRNA to the lungs of mice. Compared with the liver-targeted O-series ionizable lipids which contained ester bond in lipid tail found in previous work, such as 306-O12B, the N-series ionizable lipids with the lipid tail containing amide bond prefer to deliver mRNA to the lung. As a N-series ionizable lipid, the chemical structure of the 306-N16B is shown in Figure 4a,b. The difference of organ targeting may be due to their adsorption of different protein coronas during blood circulation caused by their different structures mentioned earlier.It has shown that the second major protein of the protein corona adsorbed by liver-targeting 306-O12B iLNPs was apolipoprotein E (ApoE), while the three dominant proteins in the protein corona adsorbed by lung-targeting 306-N16B iLNPs were serum albumin, fibrinogen beta chain, and fibrinogen gamma chain. However, the 306-N16B iLNPs showed less organ selectivity when systematically codelivered Cas9 mRNA and sgRNA in vivo, which could simultaneously activate tdTomato expression in the liver and lung of Ai14 mice, whereas single mRNA delivery could almost exclusively deliver mRNA to the lungs. This surprising phenomenon requires further investigation. Both the change of iLNPs charge and the change of lipids functional group can influence the distribution of iLNPs in vivo due to the altering of protein corona composition. Therefore, it is possible to control the organ targeting of iLNPs by controlling the composition of the outer protein corona of iLNPs.

IR-117-17 (A10-LIN) is an ionizable and biodegradable lipid specifically designed for nebulized mRNA delivery. When formulated into lipid nanoparticles (LNPs), IR-117-17 demonstrates remarkable efficacy, achieving a 300-fold enhancement in lung mRNA delivery compared to the best-performing LNP previously reported. Additionally, it shows a two-fold improvement over the leading PBAE-based delivery system, with up to a 45-fold increase in mRNA delivery efficiency to the large airways.

L649 is a next-generation, lung-targeting ionizable lipid specifically designed for systemic mRNA delivery developed by Hopewell. Belonging to the novel "N-series" lipid class, it features a unique structure with an amine-containing head group and hydrophobic tails incorporating amide bonds. This design enables L649 to form highly stable lipid nanoparticles (LNPs) that exhibit exceptional tropism for the lower respiratory tract (lungs, bronchi, trachea) following intravenous administration. It demonstrates superior efficiency in delivering therapeutic payloads (like mRNA) specifically to key lung cell types, including alveolar epithelial cells (AT1 and AT2) and bronchial cells, while minimizing off-target accumulation in organs like the liver. L649-based LNPs, particularly when formulated with helper lipids like POPE, combine high potency with significantly improved tolerability, allowing for effective dosing in vivo. This makes L649 a promising candidate for developing treatments for various lung diseases such as pulmonary fibrosis, COPD, lung cancer, and infectious diseases like COVID-19.​

THOR 76​​ is an ionizable lipid developed for lung-targeted mRNA delivery, synthesized via a high-throughput Ugi four-component reaction (U4CR). It combines spermine (N3, amine core), oleyl aldehyde (A2), oleic acid (C2), and a morpholine-functionalized isonitrile (D3). Remarkably, its ​​crude reaction mixture​​ outperforms purified forms in efficacy, suggesting synergistic impurities or intermediates enhance function. Formulated into lipid nanoparticles (LNPs) with cholesterol, DOPE, and PEG-lipid, THOR 76 LNPs exhibit ​​exceptional lung tropism​​ with secondary spleen affinity after intravenous administration. They efficiently transfect ​​pulmonary endothelial cells​​, enabling robust gene expression (e.g., Cre recombinase) and significant CRISPR-Cas9-mediated gene editing (1.22% at 0.1 mg/kg dose) in the lungs. With a particle size <150 nm, positive zeta potential, and >90% mRNA encapsulation, THOR 76 achieves targeted delivery while minimizing off-target effects in the liver. Its design overcomes limitations of cationic helper lipids, offering a potent, tolerable platform for treating pulmonary genetic disorders and cancers.

Lipid CAD9 (3-A2-7b is a cationic degradable (CAD) lipid. 3-A2-7b formulated LNP, LNP-CAD9, can deliver FLuc mRNA to the lungs in vivo. LNP-CAD9 co-delivering Cas9 mRNA/VEGFR2 single guide RNA (sgRNA) effectively induces VEGFR2 knock out in lung endothelial cells of female mice.

A3T2C7 (CP-LC-1495) is a biodegradable ionizable lipid featuring three β-propionate linkers and an azetidine polar head, formulated in four-component LNPs. It demonstrates exceptional lung-targeted mRNA delivery with 97.1% selectivity and high protein expression (1.21×10⁸ p/s) in mice. Its slightly positive zeta potential (~3.5 mV) correlates with lung tropism, likely mediated by protein corona enrichment of vitronectin and prothrombin. The β-propionate structure enables pH-sensitive biodegradability for enhanced endosomal escape while maintaining low cytotoxicity (>90% cell viability). This lipid enables organ-specific mRNA delivery without permanently charged additives, outperforming conventional SORT strategies in selectivity and expression efficiency.

Lipid 35 is an novel ionizable lipid designed to enhance the delivery of mRNA to specific tissues, particularly the lungs.Lipid 35 demonstrates superior chemical stability, especially in storage conditions. This stability ensures that the lipid maintains its integrity over extended periods, making it ideal for long-term storage and large-scale production.Lipid 35 exhibits high transfection efficiency in various cell types, including nonimmune cells, endothelial cells, and epithelial cells. Lipid 35 has demonstrated excellent biocompatibility and safety in preclinical studies. It does not cause significant liver damage or adverse immune responses, making it a safer alternative for therapeutic applications.

The AA15 lipid, an amino acid-derived ionizable lipid, integrates a carboxylic acid-containing headgroup and biodegradable branched ester tails (R2) to enhance mRNA delivery. Optimized as AA15V LNP, it exhibits a hydrodynamic diameter of 102.3 ± 4.1 nm, low polydispersity (PDI <0.15), and slightly positive zeta potential (+4–6 mV), enabling efficient tumor-targeted delivery. With a pKa ~6.1–6.4, AA15V ensures protonation in acidic endosomes, promoting mRNA release. It achieves >85% mRNA encapsulation efficiency, critical for stable saRNA delivery. In vitro, AA15V LNP-sSE-SCTs induced sustained SE-SCT expression (69% H-2Kb+β2m+ B16F10 cells at 72 h), outperforming mRNA formulations. In vivo, a single intratumoral dose of AA15V LNP-sSE-SCTs suppressed tumor growth by 22-fold in vaccinated mice, synergizing with checkpoint inhibitors (anti-PD-1/CTLA-4) for complete regression in 28.6% of lymphoma models. Ex vivo, AA15V enabled SE-SCT expression in human glioblastoma (7.1% CD45− cells) and lung cancer samples (5.8–8.7%), underscoring clinical potential. Key data: pKa ~6.3; encapsulation: 85–89%; zeta: +4–6 mV; size: 102.3 ± 4.1 nm.