Lipid 5D8 is a novel biodegradable ionizable lipid (IL) developed through a combinatorial chemistry strategy to overcome the limitations of conventional lipid nanoparticles (LNPs) in mRNA delivery. Synthesized via a one-step, solvent-free Michael addition reaction between amine and thiol monomers, 5D8 features asymmetric lipid tails and a biodegradable ester backbone, ensuring both structural versatility and reduced toxicity. In preclinical studies, 5D8-based LNPs demonstrated exceptional liver-targeting efficiency and mRNA delivery performance. A single intravenous dose (1 mg/kg) achieved 61% CRISPR-Cas9-mediated editing of the TTR gene in mice, reducing serum TTR protein by 90%, outperforming benchmark lipids like C12-200 (51% editing). Moreover, 5D8 enabled efficient delivery of base editors (ABE8.8 and CBE4max), achieving 42% PCSK9 editing (74% serum protein reduction) and correcting hereditary tyrosinemia in mice, significantly extending survival. Beyond gene editing, 5D8 LNPs effectively delivered siRNA (complete serum TTR clearance at 0.05 mg/kg) and enhanced hepatocyte targeting by enriching apolipoprotein E on particle surfaces. Crucially, 5D8 exhibited superior biocompatibility with no hepatotoxicity (normal ALT/AST levels), contrasting traditional LNPs. Its rapid biodegradability and "plug-and-play" design make 5D8 a versatile platform for mRNA therapeutics, holding broad potential for treating genetic disorders, cardiovascular diseases, and beyond. This innovation represents a critical advancement toward safer, high-efficiency clinical translation of gene-editing therapies.L

A4B4-S3 is a novel biodegradable ionizable lipid that has been meticulously designed through modular platforms and optimized specifically for mRNA delivery. It serves as a critical component of lipid nanoparticles (LNPs) and enhances mRNA delivery efficiency by facilitating endosomal escape. The structural design of A4B4-S3 leverages the Passerini reaction, a highly efficient and modular chemical method that enables the rapid generation of diverse lipid libraries. The design focuses on optimizing the methylene units between lipid headgroups and linkages to strengthen hydrogen bonding interactions with mRNA ribophosphate complexes. This enhanced hydrogen bonding allows for more effective release of mRNA from endosomes, thereby boosting delivery efficiency. Concurrently, the structural optimization improves biodegradability, reducing potential long-term toxicity risks. In experimental studies, A4B4-S3 has demonstrated superior gene editing efficacy in mouse liver compared to SM-102, a clinically prevalent lipid used in Moderna's COVID-19 vaccine. It also shows potential for repeat-dose protein replacement therapies, suggesting enhanced stability and safety for long-term treatment regimens. Technologically, A4B4-S3 not only provides a more efficient LNP formulation but also deepens the understanding of the relationship between structure and delivery efficiency. This offers new directions for the development of future mRNA therapeutics. In summary, A4B4-S3 represents a next-generation delivery carrier achieved through rational design and high-throughput screening strategies. Its performance enhancements and biodegradable properties position it as a promising candidate for gene therapies and vaccine applications.

THP1 is a tetrahydropyrimidine ionizable lipid for mRNA delivery. THP1 demonstrates higher transfection efficiency comparable to DLin-MC3-DMA (MC3). THP1 LNPs also demonstrates the ability to edit genes in specific liver tissues in a tdTomato transgenic mouse model.

306Oi10 is a branched-chain ionizable lipidoid that has shown significant promise in the generation of lipid nanoparticles (LNPs) for mRNA delivery. Its unique structural and functional properties make it a highly efficient delivery vehicle for mRNA-based therapeutics.

Lipid 48​ is a leading ionizable lipid designed for therapeutic nucleic acid delivery. Its key function is to form the core of lipid nanoparticles (LNPs) that efficiently encapsulate and deliver cargoes like mRNA and CRISPR guide RNAs into cells. Its optimized structure allows it to remain neutral in the bloodstream for low toxicity but become positively charged in acidic cellular compartments (endosomes), where it disrupts the membrane to release the therapeutic payload. Data from the patent demonstrates its superior profile: it achieves high gene editing efficiency (e.g., ~80% indel rates in vitro and 16.2% in vivo in mouse liver) while maintaining low cytotoxicity (cell viability >80% at effective doses), establishing it as an ideal candidate for gene therapy applications due to its exceptional balance of potency and safety.

L319 (LIPID 319) is a novel ionizable, biodegradable lipid for delivery of short interfering RNAs (siRNAs). L319-LPN displays rapid elimination with pKa of 6.38 and also shows well tolerated up to 10 mg/kg.

ALC 0307 is an ionizable amino lipid developed by Acuitas Therapeutics, serving as the critical functional component in lipid nanoparticles (LNPs) for targeted therapeutic delivery. As the core cationic lipid in specific LNP formulations (e.g., k-abe for CPS1-Q335X correction), its key feature is pH-dependent chargeability: it remains neutral at physiological pH but becomes positively charged in acidic environments like endosomes. This property enables efficient encapsulation of nucleic acid payloads (>97% efficiency, e.g., base editor mRNA/gRNA complexes) and facilitates endosomal escape via membrane disruption post-cellular uptake.​​ Its optimized structure promotes selective hepatocyte targeting by binding endogenous apolipoprotein E (ApoE), which subsequently interacts with LDL receptors on liver cells. Preclinical studies show rapid clearance (>99.5% plasma reduction in 14 days) and manageable transient toxicity (mild, reversible cytoplasmic vacuolation in hepatocytes, short-term ALT/AST elevation). LNPs containing ALC0307, alongside helper lipids (cholesterol, DSPC, and PEG-lipid ALC-0159), form stable ~73 nm particles with low polydispersity. This combination enables repeatable, liver-directed delivery of gene editing therapeutics with minimized off-target effects, underpinning its use in individualized in vivo gene correction therapies.

TCL053 is an ionizable amino lipid.1 It has been used in the generation of lipid nanoparticles (LNPs) and has a pKa value of 6.8. LNPs containing TCL053 and encapsulating mRNA encoding the Cas9 nuclease, in combination with LNPs containing TCL053 and encapsulating single-guide RNA (sgRNA) targeting the Rosa26 locus, have been used to induce CRISPR-mediated gene editing in the mouse gastrocnemius muscle.TCL053 is an ionizable lipid that has received FDA approval for preparing mRNA vaccines. It is a three-tailed ionizable lipid to overcome the disadvantage of nonrepeatable administration of AAV vectors. In addition, combined with limb perfusion administration, TCL053 iLNPs could transiently deliver CRISPR-Cas9 mRNA and sgRNA to multiple muscle tissues, reducing immunogenicity and increasing the safety of iLNPs. It is great progress for treating Duchenne muscular dystrophy and other diseases that require multiple doses.

SM-102 is an ionizable amino lipid that has been used in combination with other lipids in the formation of lipid nanoparticles.Administration of luciferase mRNA in SM-102-containing lipid nanoparticles induces hepatic luciferase expression in mice. Formulations containing SM-102 have been used in the development of lipid nanoparticles for delivery of mRNA-based vaccines.

Lipid 8 iLNPs were used to deliver CRISPR-Cas9 mRNA and sgRNA which targeted to the PLK1 gene. The safety and excellent intracerebral diffusion performance of lipid 8 iLNPs ensured that the survival of murine glioblastoma multiforme (GBM) mice was extended. The median survival was extended by approximately 50% and the overall survival was increased by 30%. The treatment of metastatic adenocarcinoma was executed by the EGFRtargeted lipid 8 iLNPs. These iLNPs possessed the ability of tumor targeting, which could increase the accumulation of CRISPR-Cas9 mRNA and sgRNA within the tumor cells. After a single intraperitoneal administration,
80% PLK1 gene was edited and the overall survival of mice with high-grade ovarian cancer malignant ascites was enhanced by
80% . These results demonstrate the clinical potential of CRISPR-Cas9 gene editing system can be delivered by iLNPs for treating tumors, and provide new ideas for tumor gene therapy.

306-O12B is a cationic lipidoid.306-O12B LNP is more efficient than MC-3 LNP in inducing loss-of-function mutations in Angptl3 through CRISPR-Cas9-based genome editing. It has been used in the generation of lipid nanoparticles (LNPs). Intravenous administration of LNPs containing 306-O12B and encapsulating an mRNA reporter accumulate specifically in the mouse liver. LNPs containing 306-O12B and encapsulating mRNA encoding the Cas9 nuclease (mCas9) and single-guide RNA targeting Angptl3 (sgAngptl3), the gene encoding angiopoietin-related protein 3, have been used to induce CRISPR-mediated gene knockdown in mice resulting in a reduction of serum Angptl3 protein, LDL, and triglyceride levels. A novel ionizable lipids library was constructed by a combinatory solvent-free Michael addition reaction between disulfide bondincorporated acrylate lipid tails and amine-containing heads. In this library, the tail-branched bioreducible ionizable lipid 306-O12B was screened out. Due to the presence of special ester bonds and branches in lipid tails, the accumulation of iLNPs in the liver was increased, and endosome escape was prompted. These iLNPs were used to deliver CRISPR-Cas9 mRNA and sgRNA targeting to angiopoietin-like 3 (Angptl3). Compared with FDA-approved MC3, 306-O12B induced more specific and efficient Angptl3 gene knockout in the liver, resulting in significant decrease in the levels of serum Angptl3 protein, low-density lipoprotein cholesterol (LDL-C), and triglyceride. According to the molecular shape hypothesis outlined several decades ago, the increase of branches can create ionizable lipids with more cone-shaped structure to enhance the destructiveness of the membrane structure of the endosome and increase mRNA release. However, it is unknown whether the structural stability of iLNPs will be sacrificed with the increase of branches. The optimal branches and chain length need to be further explored.

246C10 is a synthesized ionizable lipid. 246C10 can be formulated into lipid nanoparticles (LNPs) with dioleoylphosphatidylethanolamine (DOPE), cholesterol, and C16-PEG2000 ceramide (PEG-lipid) as well as mRNA. The lipid nanoparticle formulations can be used for mRNA delivery. To obtain iLNPs that could specifically target liver sinusoidal endothelial cells (LSECs), six different ionizable lipids (241C10 to 246C10) were synthesized by an epoxide ring-opening reaction with piperazine- or piperidine-containing amines. Biodistribution and gene regulation of various iLNPs were assessed in vivo, and the results showed that the 246C10 iLNPs (containing piperazine amine) had the highest luciferase expression in the liver. When further analyzing the 246C10 iLNPs transfection efficiency in different types of liver cells, it was found that tdTomato fluorescence was mainly concentrated in hepatocytes, not in LSECs. Figure 6f shows that 80% of hepatocytes are fluorescent, 40% of LSECs are fluorescent, and 20% of Kupffer cells are fluorescent. Due to the mannose receptor on LSECs, mannose-PEG lipid was introduced into 246C10 iLNPs to alter the distribution of iLNPs in different liver cells. As shown in Figure 6g, tdTomato fluorescence distribution was 15% of hepatocytes, 70% of LSECs, and 15% of Kupffer cells, significantly improved the ability of iLNPs to actively target LSECs. In contrast, this work indirectly shows that the iLNPs with piperazine head lipid are more able to deliver mRNA to the liver and translate the target protein than the iLNPs with piperidine head lipid. It is worth mentioning that the preparation buffer of 246C10 iLNPs could influence the encapsulation efficiency of mRNA. With the addition of sodium chloride in the citrate buffer, the encapsulation efficiency of CRISPR-Cas9 mRNA and sgRNA was increased. These iLNPs were able to treat hemophilia safely, without causing hepatotoxicity, the immune response induced by Cas9 and off-target editing.

C12-200 is a well-known cationic lipid used in the formulation of lipid nanoparticles (LNPs) for the delivery of therapeutic nucleic acids, including siRNA, mRNA, and CRISPR components. It is widely recognized for its high in vivo potency at low doses and is often used as a positive control ionizable lipid in research exploring new ionizable lipids.

CKK-E12 is a ionizable lipid in combination with other lipids make up the lipid nanoparticles which are used to deliver RNA-based therapeutics. cKK-E12 was highly selective toward liver parenchymal cell in vivo.Multitail lipids usually have three or more tails and tend to form more cone-shaped structures due to the increase of tail crosssection, which enhances the endosome escape and mRNA delivery efficiency.CKK-E12 is an ionizable lipid with four lipid tails and diketopiperazine core-based head. It has shown excellent efficiency in delivering CRISPR-Cas9 mRNA and sgRNA.cKK-E12 iLNPs encapsulated mRNA was used to investigate the effect of Toll-like receptor 4 (TLR4) on iLNPsmediated mRNA delivery, and it has been demonstrated that the targeting, safety and efficacy of iLNPs are closely related to disease state. In other words, even though iLNP delivers therapeutic mRNA to a given cell type in one disease state, it is not guaranteed to deliver mRNA to the same cell type in another disease. As same as MC3 and C12-200, CKK-E12 is also used to be a positive control ionizable lipid when exploiting new ionizable lipids.

ATX-126(ATX-0126, 10p) is an ionizable cationic lipid (pKa = 6.38).It has been used in the generation of lipid nanoparticles (LNPs) for the delivery of siRNA. Intravenous administration of LNPs containing ATX-126(ATX-0126, 10p) and encapsulating Factor VII siRNA decrease Factor VII blood levels in mice.

D-Lin-MC3-DMA(MC3) is the most potent cationic lipid that has been synthesized for Lipid nanoparticles (LNPs) to deliver the siRNA.

11-10-8 is an ionizable cationic lipid (pKa = 6.22) that has been used in the generation of lipid nanoparticles (LNPs) for mRNA delivery in vivo.1 LNPs containing 11-10-8 and encapsulating mRNA encoding the Cas9 nuclease and small-guide RNA (sgRNA) targeting transthyretin (TTR), a thyroid hormone carrier protein, decrease serum levels of TTR in mice. LNPs containing 11-10-8 and encapsulating mRNA encoding human fibroblast growth factor 21 (hFGF21) increase serum levels of hFGF21, decrease body and liver weights, and reduce the liver steatosis score in a mouse model of obesity induced by a high-fat diet.

FTT5 is a lipid-like compound for efficient delivery of long mRNAs in vivo.

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.

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.

ssPalmO-Phe(SS-OP) is a self-degradable material for the delivery of oligonucleotides. ssPalmO-Phe is a self-degradable derivative of ssPalm that is self-degraded in the intraparticle space by a specific hydrolytic reaction. ssPalmO-Phe is beneficial for overcoming the plasma/endosomal membrane, LNP-ssPalmO-Phe can be used to deliver both nucleic acids.

LP-01 is an ionizable cationic amino lipid (pKa = ~6.1). It has been used in the generation of lipid nanoparticles (LNPs). LNPs containing LP-01 and encapsulating both Cas9 mRNA and modified single-guide RNA (sgRNA) for the transport protein transthyretin (Ttr) induce gene editing in liver cells in mice in a dose-dependent manner resulting in reduced serum Ttr levels for at least 12 months.