Acid-degradable Cationic Lipid (ADC) composed of cationic lipid is synthesized with the azido-acetal linker and used to generate RD-LNPs, which significantly improves the performance of LNP-mRNA complexes in vitro and in vivo.

GVS-18-B6 is a silicon ether-based ionizable lipid developed by Genevant, optimized for mRNA-LNP delivery, characterized by a short-chain trialkyl structure with three C10 alkyl chains (including a cis double bond) and a dimethylamino (DMA) head group linked via a 4-carbon spacer (pKa ~6.15). Its LNP formulations exhibit a narrow particle size distribution (89 nm, PDI=0.06), high mRNA encapsulation efficiency (90%), and pH-dependent surface charge (−0.11 mV at pH 7.5 vs. +2.69 mV at pH 5.5), facilitating endosomal escape. ​​In vivo​​, GVS-18-B6 demonstrated superior liver-specific mRNA expression (5.30×10⁷ pg EGFP/g liver, 2.6× higher than MC3) with minimal spleen accumulation (liver/spleen ratio 92:1 vs. MC3’s 10:1), attributed to rapid non-enzymatic hydrolysis of its silicon ether bonds. This mechanism enables near-complete hepatic clearance within 6 hours in mice and 24 hours in NHPs, avoiding long-term organ retention (MC3 retained 25% in liver after 28 days). Compared to benchmarks (MC3, SM-102, LP-01), GVS-18-B6 showed enhanced potency in RBC hemolysis assays (pH 6.2), indicating earlier endosomal membrane disruption, and maintained stability through 12-month frozen storage or repeated freeze-thaw cycles. ​​Toxicity profiling​​ revealed minimal immunogenicity (MCP-1 levels 0.58×10⁶ vs. MC3’s 1.10×10⁶) and no ALT/AST elevation or anti-PEG antibody induction in NHPs after repeated dosing. Its species-agnostic clearance, low off-target effects, and high tolerability (6 mg/kg dose in mice) position GVS-18-B6 as a leading candidate for chronic disease therapies requiring frequent mRNA administration.

Lipid 29 analogue-3 is an ionizable lipid designed for the delivery of RNA-based therapeutics, such as mRNA or siRNA.

Acuitas II-12 is an novel ionizable amine lipid used for mRNA delivery from Acuitas Therapeutics patent WO2016176330A1

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.

ND-O1 (SM-86 Analog-2) is a novel ionizable lipid designed to improve the delivery of siRNA via lipid nanoparticles (LNPs) for treating liver fibrosis. It is derived from SM-86 (structurally similar to SM-102, used in COVID-19 mRNA vaccines) but incorporates an ether bond within its hydrophobic tail, a first-of-its-kind modification aimed at enhancing delivery efficiency. In Vitro Efficiency: ND-O1 LNPs (LNP-O1) showed significantly higher siRNA transfection efficiency in activated fibroblasts compared to Lipid 5 LNPs (LNP-M). In Vivo Efficacy: In a CCl4-induced liver fibrosis mouse model, LNP-O1/siHSP47 (loaded with HSP47-targeting siRNA) reduced HSP47 expression by ~84%, threefold more effective than LNP-M. This led to a dramatic reduction in collagen deposition and marked improvement in liver fibrosis. Safety: The ether bond modification did not introduce additional toxicity, maintaining biocompatibility. ND-O1 represents a breakthrough in ionizable lipid design, demonstrating that strategic placement of ether bonds in hydrophobic tails can enhance LNP performance without compromising safety. Its success highlights its potential for clinical translation in RNA-based therapies for liver fibrosis and other hepatic diseases.

Acuitas Lipid III-7 is an novel ionizable amine lipid used for mRNA delivery from Acuitas Therapeutics patent US 10,166,298 B2.

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.

​TOT-5​​, a tri-oleoyl-Tris ionizable lipid (pKa 6.2), enables splenic B cell-targeted mRNA delivery via 15% DSPC-incorporated LNPs. Its charge-neutral, hydrophobic surface minimizes hepatic ApoE uptake and enhances complement C3 adsorption, facilitating CD21/35-mediated uptake by marginal zone B cells. In vivo, intravenous 15%DSPC-LNPs showed 8-fold higher spleen-to-liver luciferase expression vs 3%DSPC, with anti-CD21/35 blocking 60% B cell uptake. Intramuscular administration induced robust OVA-specific IgG (10^5 titer) and CTL responses (3.5% tetramer+ CD8+ T cells) while reducing hepatotoxicity (ALT/AST levels ≤40 U/L vs SM-102-LNPs' 80-120 U/L). Cryo-ET confirmed stable lamellar structures (80-100 nm, ζ-potential -2 mV). This formulation achieves safe, ligand-free splenic targeting for mRNA vaccines. 

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.

PPZ-A10 is an ionizable cationic lipid.It has been used in the generation of lipid nanoparticles (LNPs) for the delivery of siRNA and mRNA in vitro and in vivo. Intraperitoneal administration of LNPs containing PPZ-A10 and encapsulating an mRNA reporter preferentially accumulates in hepatic Kupffer cells and splenic macrophages in mice.

93-O17O is a chalcogen-containing ionizable cationic lipidoid. It has been used in the generation of lipid nanoparticles (LNPs). LNPs containing 93-O17O localize to the spleen after intravenous injection into mice.LNPs containing 93-O17O have been used for the delivery of Cre recombinase and ribonucleoproteins for genome editing in mice and for the intratumoral delivery of cGAMP to enhance cross-presentation of tumor antigens.

Lipid88​​ is a high-performance, novel ionizable lipid component engineered for advanced mRNA-LNP vaccine delivery. LNP88 formulation demonstrates superior biodistribution, achieving >10-fold higher transfection efficiency in spleen and lymph nodes compared to benchmark lipids like ALC-0315 via intramuscular delivery. When encapsulating antigen-encoding mRNA (e.g., optimized mCSA construct), Lipid-88 based LNPs drive robust humoral and cellular immunity, enabling complete protection against challenging SARS-CoV-2 variants (WA1/2020, Omicron BA.1, BQ.1) in preclinical models. Its design prioritizes potent immunogenicity with favorable safety profiles.

C14-4 (C14-494,Lipid B-4,Lipid B4) is a novel ionizable lipid with the highest T-cell transfection efficiency and low cytotoxicity.The C14-4 ionizable lipid has been explored for CAR-T therapy.To screen the excellent formulations for mRNA delivery, a lipid library of 24 ionizable lipids was constructed to make iLNPs, which were used to deliver luciferase mRNA into Jurkat cells.[115] The optimal iLNPs formulation was C14-4 iLNPs (C14-4 ionizable lipid, DOPE, chol, and PEG at a molar ratio of 35%, 16%, 46.5%, and 2.5%) (Figure 6c). The optimal dose of luciferase mRNA for C14-4 iLNPs was 30 ng. Compared with electroporated CAR T cells, the CAR T cells engineered via C14-4 iLNPs showed potent cancer-killing activity when they were cocultured with Nalm-6 acute lymphoblastic leukemia cells. To obtain a safer and more effective CAR mRNA delivery vehicle, the orthogonal design provided 256 potential formulations, and 16 representative iLNPs formulations were evaluated.Through evaluating the safety, delivery efficiency, and transfection efficiency of 16 iLNPs, the formulation B10 (C14-4 ionizable lipid, DOPE, chol, PEG at a molar ratio of 40%, 30%, 25%, and 2.5%) was screened out as the optimal performing formulation. The luciferase expression based on B10 formulation was increased threefold than the initial formulation. Reducing the accumulation and clearance of iLNPs in the liver can increase the expression of CAR mRNA in T cells, further improving the therapeutic effect of CAR-T. Studies have shown that cholesterol analogs can alter the mechanisms of intracellular circulation and enhance the delivery of mRNA, which may be related to the reduced recognition of iLNPs by the Niemann Pick C1 (NPC1) enzyme.The addition of a hydroxyl group to various locations in the cholesterol molecule can alter the binding kinetics between the modified cholesterol and NPC1, and reduced NPC1 recognition of cholesterol. The results showed that replacement of 25% and 50% 7 α-hydroxycholesterol for cholesterol in iLNPs improved mRNA delivery to primary human T cells in vitro by 1.8-fold and twofold, respectively.C14-4 is one of the ionizable lipids to efficiently deliver mRNA to Jurkat cells or primary human T cells. It will effectively promote the development of mRNA delivery by iLNPs for CAR-T therapy.

503O8,12​​ is an ionizable lipidoid synthesized via Michael addition, combining a hydrophilic amine headgroup ("503" series) with two hydrophobic branched acrylate tails (C8 and C12 chains, likely with unsaturated bonds). Its design emphasizes organ-specific delivery, exhibiting ​​spleen-tropic targeting​​ in vivo.

YSK 12C4 is an ionizable cationic lipid primarily used to enhance siRNA cellular delivery via multifunctional envelope-type nanodevices (MEND). YSK 12C4 promotes siRNA uptake and endosomal escape, effectively silencing genes in human immune cell lines.

Lipid C12-A1 is an ionizable lipid. C12-A1-LPN is a potent and safe LNP platform to deliver Foxp3 mRNA to CD4+ T cells to engineer immunosuppressive FP3T cells. C12-A1 has a slightly lower average cell viability than C14-A1.

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.

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.

TD5 is a brain-targeting lipid nanoparticle (BLNP) engineered for efficient mRNA delivery to the central nervous system (CNS) via intrathecal injection. It incorporates a tryptamine-derived ionizable lipid headgroup, myristic acid hydrocarbon tails, and a biodegradable carbonate ester linker, enabling pH-dependent mRNA encapsulation (81.7% efficiency) and brain cell-specific targeting. With a hydrodynamic diameter of 107.5 nm, near-neutral pKa (7.30), and mild positive charge, TD 5 demonstrates superior CNS tropism through serotonin receptor (5-HT1A)-mediated endocytosis. In vitro, TD-5 achieved 80.8% GFP expression in SH-SY5Y neuronal cells, outperforming MC3 LNPs by 50-fold. Following intrathecal administration in mice, TD-5 mediated GFP expression in 29.6% of neurons and 38.1% of astrocytes brain-wide, with 10-fold higher CNS specificity than peripheral organs. Genome editing studies showed TD5-delivered Cas9/sgRNA induced tdTomato activation in ≈30% of neurons and 40% of astrocytes across key brain regions. Safety profiling revealed minimal systemic immune responses (lower IL-6, IL-12p40 vs MC3 LNPs), normal hepatic/renal biomarkers, and no histopathological toxicity. The optimized structure balances myristic chain hydrophobicity for membrane interaction, ionizable amines for mRNA complexation, and tryptamine-mediated targeting for enhanced CNS uptake, establishing TD5 as a promising platform for CNS gene therapies.

NT1-O14B is a tryptamine-containing cationic lipidoid.1 It has been used in combination with other lipids in the formation of lipid nanoparticles (LNPs). Intravenous administration of LNPs containing NT1-O14B and encapsulating antisense nucleotides against tau decreases tau brain levels in mice.

NT1-O12B, an endogenous chemical and a neurotransmitter-derived lipidoid (NT-lipidoid), is an effective carrier for enhanced brain delivery of several blood-brain barrier (BBB)-impermeable cargos. Doping NT1-O12B into BBB-impermeable lipid nanoparticles (LNPs) gives the LNPs the ability to cross the BBB. NT-lipidoids formulation not only facilitate cargo crossing of the BBB, but also delivery of the cargo into neuronal cells for functional gene silencing or gene recombination.

​​200Oi10​​ is an ionizable lipidoid used in lipid nanoparticles (LNPs) for RNA delivery. Structurally, it features ester-conjugated cleavable lipid tails, enhancing biodegradability and reducing toxicity compared to non-cleavable analogs. Preclinical studies show that 200Oi10-based LNPs primarily accumulate in the liver (97.7%) after intravenous administration. However, intraperitoneal injection redirects biodistribution, achieving 46.4% pancreatic uptake, which can be further amplified by incorporating cationic lipids like DOTAP. This unique tropism enables pancreas-targeted mRNA delivery. 200Oi10's ester linkages promote rapid clearance, improving biocompatibility while maintaining siRNA/mRNA delivery efficiency. Its design exemplifies the use of degradable lipidoids to balance organ specificity, efficacy, and safety in RNA therapeutics.

18-2-9b2 is a dendron-like degradable ionizable lipid which facilitates mRNA delivery to splenic macrophages. 18-2-9b2 LNP encapsulating therapeutic BTB domain and CNC homologue 1 (BACH1) mRNA exhibited proficient BACH1 expression and subsequent Spic downregulation in splenic red pulp macrophages (RPM) in a Spic-GFP transgene model.

CF3-2N6-UC18​​ is a rationally designed chloroquine-inspired ionizable lipid that enables robust mRNA delivery and genome editing. It integrates three modular components: a 7-trifluoromethyl-substituted quinoline scaffold (mimicking chloroquine’s endosomolytic properties), a hexamethylenediamine linker with two ionizable nitrogen atoms (pH-responsive protonation), and two unsaturated oleyl (C18:1) hydrophobic tails (enhancing membrane fusion and nanoparticle stability). This lipid self-assembles into ecoLNPs (endosomolytic chloroquine-like lipid nanoparticles) with spherical morphology (~200 nm diameter, 98% mRNA encapsulation). Its pH-sensitive activity triggers endosomal escape through dual mechanisms: ​​proton sponge effect​​ (buffering endo-lysosomal pH) and ​​saposin B-mediated membrane disruption​​ (molecular docking confirms chloroquine-like binding to lysosomal saposin B). In vitro, ecoLNPs outperform commercial reagents (18.9-fold higher mRNA delivery than Lipofectamine 2000) and penetrate 3D cell models. They resist serum/RNase degradation and retain >90% activity after 7-day storage at 4°C. In vivo, ecoLNPs achieve tissue-specific mRNA expression via multiple routes (intravenous, intramuscular, etc.), with strong lymph node tropism (90.2% after intramuscular injection) comparable to SM-102 LNPs (Moderna’s COVID-19 vaccine carrier). They mediate efficient Cre mRNA-driven recombination and CRISPR-Cas9 editing in transgenic mice. CF3-2N6-UC18’s modular design, stability, and dual endosomal escape strategies position it as a versatile platform for mRNA vaccines, gene therapy, and genome editing applications.

H7T4-4 is an ionizable lipid designed for mRNA delivery via lipid nanoparticles (LNPs). It features a cyclic amine headgroup (derived from cyclen tetrahydrochloride) and four C14 hydrophobic alkyl tails, synthesized through a Michael addition reaction between cyclen and 1,2-epoxytetradecane. With a high transition temperature (Tm = 58.6°C) due to strong intermolecular interactions from its cyclic headgroup and multi-tail structure, H7T4-4 alone forms rigid aggregates incompatible with mRNA encapsulation. However, when blended with low-Tm helper lipids (e.g., DOPE, Tm = -16°C), the system’s overall Tm decreases, enabling stable LNP formation. Optimized formulations (20% H7T4-4, 41% DOPE, 38% cholesterol, 1% DMG-PEG) exhibit efficient mRNA encapsulation (>90%) and transfection. Structural analyses (SAXS, cryo-TEM) confirm monodisperse LNPs with lamellar/hexagonal phases. In vivo, H7T4-4 LNPs show tumor-targeted and intranasal mRNA delivery with reduced off-target accumulation compared to SM-102-based LNPs. This rational design highlights Tm-guided helper lipid selection to overcome rigidity challenges in ionizable lipids.

Lipid B3 is a biodegradable ionizable lipid for liver targeted delivery. Lipid B3-LNP shows high delivery efficacy and low toxicity in delivering RNA to liver cells.

DODAP, also known as 1,2-Dioleoyl-3-dimethylammonium-propane, is a cationic lipid. It has been used as a component in liposomes that can be used to encapsulate siRNA, immunostimulatory oligodeoxynucleotides, antisense oligonucleotides, or chemotherapeutic agents for in vitro and in vivo delivery.