SM86 is a cationic, ionizable lipid developed by Moderna as a core component of its lipid nanoparticle (LNP) platform for mRNA therapeutic delivery.SM-086 is structurally optimized and analogous to SM-102 (used in Moderna’s COVID-19 vaccines), with modifications aimed at enhancing mRNA delivery efficiency and safety.SM-86 serves as the primary cationic lipid in three investigational mRNA therapies targeting rare metabolic disorders:mRNA-3927: Restores propionyl-CoA carboxylase activity in propionic acidemia (PA). mRNA-3705: Delivers methylmalonyl-CoA mutase mRNA for methylmalonic acidemia (MMA). mRNA-3210: Provides phenylalanine hydroxylase mRNA to treat phenylketonuria (PKU).

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.

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.

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.

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.

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.

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.

IC8 is an ionizable cationic lipid. It has been used in combination with other lipids for the formation of lipid nanoparticles (LNPs). Immunization with severe acute respiratory coronavirus 2 (SARS-CoV-2) spike glycoprotein mRNA in IC8- and manganese-containing LNPs induces IgG responses to SARS-CoV-2 Delta and Omicron variants in mice.1 Administration of mRNA encoding B7-H3 X CD3 bispecific T cell engaging (BiTE) antibodies in IC8-containing LNPs reduces tumor growth in MV4-11 and A375 mouse xenograft models.

93-O17S is an imidazole-based synthetic lipidoid for in vivo mRNA delivery. Lipid nanoparticles (LNPs) with 93-O17S promotes both the cross-presentation of tumor antigens and the intracellular delivery of cGAMP (STING agonist).

9322-O16B is a lipidoid for the efficient delivery of antiCD19 mRNA CAR to murine primary macrophages. LNP 9322-O16B is more efficient than delivery with lipofectamine 2000 (LPF2K) or MC3.

113-O12B is a disulfide bond-containing ionizable cationic lipidoid. 113-O12B LNP, an LN-targeting LNP delivery system, is developed for a mRNA cancer vaccine. The 113-O12B/mRNA shows enhanced expression in APCs compared with ALC-0315/mRNA, indicating the LN-specific targeting ability.

DODMA, also known as MBN 305A is a a cationic lipid containing the unsaturated long-chain (18:1) oleic acid inserted at both the sn-1 and sn-2 positions. It has been used in the composition of lipospomes formulated as stable nucleic acid lipid particles that can encapsulate siRNA or other small molecules to be used for drug delivery

Lipid 10 is a novel ionizable cationic lipid be used for delivery of therapeutic RNA to the Bone Marrow in Multiple Myeloma Using CD38-Targeted with Lipid 10-LNP.

DLin-KC2-DMA is a highly potent ionizable lipid used in the formulation of lipid nanoparticles (LNPs) for the delivery of siRNA. It represents a significant advancement over earlier generations of lipids, such as DLin-DMA, due to its dramatically improved gene silencing efficiency.

ALC 0366 is an ionizable cationic lipid (pKa = 6.25) from Biontech,which is derived from ALC-0315. ALC0366 has been used as a key component of LNP to deliver BNT142, a lipid nanoparticle (LNP)-formulated RNA (RNA-LNP) encoding a T cell-engaging bispecific antibody that monovalently binds the T cell marker CD3 and bivalently binds claudin 6 (CLDN6), an oncofetal antigen that is absent from normal adult tissue but expressed on various solid tumors.

Iso-A11B5C1 is an ionizable lipid. The iso-A11B5C1 LNP demonstrates a high level of muscle-specific mRNA delivery efficiency. exhibiting transfection efficiency comparable to the commercially available lipid SM-102, while considerably reducing inadvertent mRNA expression in main organs such as the liver and spleen.Additionally, study results show that intramuscular administration of mRNA formulated with iso-A11B5C1 LNP caused potent cellular immune responses, even with limited expression observed in lymph nodes.

Moderna Lipid 48 is an novel ionizable amine lipid used for mRNA delivery from Moderna patent WO2017049245A2

OF-C4-Deg-Lin is a novel ionizable lipid for RNA delivery. OF-C4-Deg-Lin LNPs entrapping mRNA coding for luciferase induce the majority of protein expression in the spleen, with minimal translation in the liver, and negligible translation in other organs. OF-C4-Deg-Lin LNPs entrapping mRNA coding for luciferase induce the majority of protein expression in the spleen, with minimal translation in the liver, and negligible translation in other organs. To improve the mRNA delivery to extrahepatic tissues, a series of degradable diketopiperazine-based ionizable lipids were synthesized. Through evaluating the mRNA functional activity delivered by iLNPs, it was found that the ionizable lipids with doubly unsaturated lipid tails and linkers containing a length of four carbon aliphatic chain (Of-C4-Deg-Lin) could deliver the mRNA more efficiently. Moreover, compared with cKK-E12 and Invivofectamine, Of-C4-Deg-Lin could specifically induce more than 85% of firefly luciferase expression in spleen,minimal expression in the liver, and insignificant expression in other tissues.

Acuitas Lipid III-25 is an novel ionizable amine lipid used for mRNA delivery from Acuitas Therapeutics patent US 10,166,298 B2, with pKa 6.22, Liver Luc 1648 for 0.3mgkg(ng luc/g liver), Liver Luc 13880 for 1mgkg(ng luc/g liver) . It is an analgous of ALC-0315, showing higher activity than ALC-0315.

Moderna Lipid 26（Lipid M） is an ionizable cationic lipid (pKa = 6.75) that has been used in the generation of lipid nanoparticles (LNPs) for mRNA delivery in vivo. LNPs containing lipid M and encapsulating mRNA encoding influenza virus genes increase anti-influenza virus IgG titers in cynomolgus monkeys without inducing local edema, erythema, or systemic levels of IL-6.

4A3-SC8 is a novel Ionizable amino lipid for RNA delivery.The CRISPR-Cas9 gene editing system has been a hotspot in the field of gene therapy, especially the gene correction induced by homology-directed repair (HDR). However, its application has various obstacles, such as large molecular weight, poor stability, off-target risk, and the complexity of codeliver multiple genes. Farbiak et al. established a novel ionizable lipid library consisting of four distinct amine cores (3A3, 3A5, 4A1, 4A3) and nine peripheries with different alkyl chain lengths (SC5-SC14), and screened out a class of iLNPs with ability of encapsulating Cas9 mRNA, sgRNA and donor DNA simultaneously. The delivery efficiency (quantified by luciferase mRNA expression) and iLNPs toxicity were evaluated with three different cell lines (HEK293T, HeLa, and IGROV-1), indicating the formulation containing 4A3-SC8 was the best. 4A3-SC8 iLNPs successfully induced HDR in HEK293 cells by one-pot delivery of Cas9 mRNA, sgRNA, and the correct ssDNA template. Confocal microscopy imaging showed that a portion of blue fluorescence in cells was corrected to green fluorescence. Furthermore, the nucleic acid ratios of Cas9: sgRNA: donor DNA loading in iLNPs at a ratio of 2:1:3 could maximize the HDR efficiency with the editing efficiency up to 23%, which breaks through the current bottleneck of HDR efficiency of only 1–5%. This progress is undoubtedly an important advance in the gene therapy field to cure diseases caused by genetic mutations.

CICL1 (L829)​​ is a ​​novel ionizable cationic lipid​​ specifically engineered for ​​targeted lipid nanoparticles (tLNPs)​​ that enables efficient in vivo delivery of mRNA payloads to ​​CD8+ T cells​​. Designed to overcome limitations of conventional LNPs, CICL-1 (L-829)​​significantly ​​reduces off-target delivery to the liver​​ and exhibits ​​rapid clearance​​ compared to benchmark lipids like ALC-0315, while demonstrating ​​enhanced biodegradability and tolerability​​ in rodent and primate models. When incorporated into CD8-targeted tLNPs, CICL 1 (L829 enables ​​preferential transfection of CD8+ T cells​​ over other immune subsets, facilitating the generation of functional ​​anti-CD19 or anti-CD20 CAR T cells directly *in vivo​​*. These tLNP-engineered CAR T cells mediate ​​rapid, deep B-cell depletion​​ in humanized mice and cynomolgus monkeys, with repopulating B cells exhibiting a naïve phenotype suggestive of immune reset. By eliminating the need for ex vivo manufacturing or lymphodepleting chemotherapy, the L829-tLNP platform represents a ​​safer, scalable approach​​ for accessible CAR T therapy in oncology and autoimmune diseases.