NC-TNP (noncationic thiourea lipids nanoparticles) could compress mRNA by strong hydrogen bonds interaction between thiourea groups of NC-TNP and the phosphate groups of mRNA. NC-TNP could escape the recycling pathway to inhibit the egress of internalized nanoparticles from the intracellular compartment to the extracellular milieu. NC-TNP-encapsulated mRNA shows higher gene transfection efficiency in vitro and in vivo than mRNA-LNP formulation. NC-TNP also shows spleen targeting delivery ability with higher accumulation ratio (spleen/liver), compared with traditional LNP.The C18 non-cationic thiourea lipid self-assembles into ~100 nm nanoparticles with neutral surface charge, utilizing strong hydrogen bonding between its thiourea groups and mRNA phosphate groups for efficient mRNA complexation. This delivery system demonstrates significantly enhanced EGFP expression efficiency—2.3-fold higher than standard C6/C12 formulations—in DC2.4, B16, and 4T1 cells, while sustaining luciferase activity for over 20 days post-subcutaneous injection. It exhibits exceptional stability, maintaining >94% mRNA integrity and <10% particle size variation after 30-day lyophilized storage. Importantly, the nanoparticles show pronounced spleen-targeting capability with 20-fold greater accumulation in the spleen versus liver, effectively activating twice the level of antigen-specific CD8⁺ T cells. Critically, the system avoids cationic lipid-associated toxicity, inducing no detectable IL-6/CXCL10 inflammation and causing no histopathological damage in cardiac or splenic tissues, thus establishing a novel high-efficacy, low-toxicity mRNA delivery platform.

VL422 is an ionizable cationic lipid. It has been used in the generation of lipid nanoparticles (LNPs) for the delivery of CRISPR complementary single-guide RNA (sgRNA) and Cas9 mRNA for gene editing in vitro and in vivo. LNPs containing VL422 and encapsulating Cas9 mRNA and sgRNA targeting the gene encoding angiopoietin-related protein 3 (ANGPTL3), a protein whose loss-of-function decreases LDL, HDL, and cholesterol plasma levels, induce a deletion in a premature stop codon in ANGPTL3 in the livers of cynomolgus monkeys.

CL15F 6-4 is a short-tail ionizable lipid from the piperidine-based CL15F series, characterized by its symmetric branched structure with a 6-carbon main chain and 4-carbon side chain. This specific tail length critically determines the lipid nanoparticle's (LNP) properties, resulting in larger particles with a high surface density of the phospholipid DSPC. This elevated DSPC density reduces interactions with serum proteins like ApoE, minimizing rapid liver clearance and shifting mRNA delivery preference towards the spleen. Consequently, CL15F 6-4 LNPs achieve efficient, endogenous spleen-targeted delivery, making them a highly promising candidate for enhancing vaccine efficacy by preferentially transfecting antigen-presenting cells without complex functionalization.

CL15F 9-5, a piperidine-based ionizable lipid, exhibits favorable properties for mRNA delivery in lipid nanoparticles (LNPs). Its apparent pKa ranges between 6.24–7.15, ideal for mRNA encapsulation and endosomal escape. LNPs formulated with CL15F 9-5 (50:38.5:10:1.5 molar ratio of ionizable lipid:cholesterol:DSPC:DMG-PEG2k) demonstrated high mRNA encapsulation efficiency (>90%) and maintained physicochemical stability (size, PDI, zeta potential) during storage at 4°C for 5 months . In vitro, CL15F 9-5 LNPs showed superior luciferase expression in HEK-293T cells compared to CL4F-based LNPs. In vivo, liver-targeted LNPs delivered hEPO mRNA effectively, with sustained serum hEPO levels post-storage. Intravenous administration of FLuc mRNA-loaded CL15F 9-5 LNPs yielded strong hepatic bioluminescence, confirming liver tropism. As a vaccine candidate, CL15F 9-5 induced robust antigen-specific cellular immunity in mice, with a 14-fold increase in IFN-γ spots compared to SM-102. Its enhanced stability is attributed to reduced aldehyde impurities, minimizing mRNA-lipid adduct formation.

Lipid 15, as disclosed in US Patent US 20250381150 A1 assigned to Genzyme Corporation, is an ionizable lipid used in lipid nanoparticles (LNPs) for targeted nucleic acid delivery. It features a specific structure that enables efficient encapsulation and transfection of mRNA into cells such as immune cells and hematopoietic stem cells. Experimental data show that LNPs containing Lipid 15 achieve over 80% transfection efficiency with sustained protein expression, outperforming other lipids.

KC3-OA, chemically known as 3-((S)-2,2-di((Z)-octadec-9-en-1-yl)-1,3-dioxolan-4-yl)-N,N-dimethylpropan-1-amine, is an ionizable cationic lipid (ICL) optimized for lipid nanoparticle (LNP) formulations in nucleic acid delivery, particularly for mRNA vaccines. It features a unique structure with mono-unsaturated alkyl chains (C18:1), which enhances oxidative stability compared to polyunsaturated analogs like KC3, while maintaining efficient membrane fusion and endosomal escape capabilities. In LNP compositions, KC3-OA is typically incorporated at 46–54 mol% of total lipids, with an N/P ratio of 4–6 relative to mRNA, ensuring high encapsulation efficiency and transfection potency. Experimental data demonstrate that KC3-OA-based LNPs achieve superior mRNA expression in human dendritic cells, outperforming alternatives like KC3-PA or KC3-01 in both in vitro and in vivo models. For instance, in FIG. 2, KC3-OA LNPs showed ~2-fold higher mCherry expression at low mRNA doses (0.1 μg/mL) due to improved cellular uptake and reduced degradation. Its synergy with anionic phospholipids like DPPS (5 mol%) further enhances dendritic cell targeting via receptor-mediated internalization, leading to robust CD4+ and CD8+ T-cell responses against Mycobacterium tuberculosis antigens. This balance of stability, efficiency, and immunogenicity makes KC3-OA a leading candidate for next-generation vaccines.

AMG-1541 is a degradable cyclic amino alcohol ionizable lipid optimized for mRNA vaccine delivery using lipid nanoparticles (LNPs). Formulated typically with DOPE, cholesterol, and PEG-lipids, AMG 1541 LNPs have a diameter of ~85 nm, PDI of 0.107, and encapsulation efficiency of 67%, ensuring stability and efficient mRNA delivery. In vitro, it outperforms benchmarks like SM-102, showing enhanced transfection in cells such as C2C12 and PBMCs. In vivo, intramuscular administration in mice results in robust protein expression within 6 hours and induces potent immune responses, including high antibody titers and Th1-biased T-cell activation, with minimal inflammation. Mechanistically, its β-hydroxyl groups form hydrogen bonds with mRNA phosphate backbones, facilitating endosomal escape. AMG1541 degrades rapidly under enzymatic conditions, reducing long-term toxicity, and is effective for vaccines targeting pathogens like influenza and SARS-CoV-2, making it a promising candidate for clinical applications.

CL15F 7-5 is a piperidine-based ionizable lipid from the CL15F library, characterized by a symmetrically branched tail structure with a 7-carbon main chain and a 5-carbon side chain. This moderate tail length positions it between short-tail (e.g., CL15F 6-4) and long-tail (e.g., CL15F 14-12) variants, granting it a unique balance in mRNA delivery properties. Its LNPs exhibit optimized organ selectivity, enabling significant mRNA expression in both the spleen and muscle, as demonstrated by in vivo luciferase assays following intravenous and intramuscular administration. This lipid structure facilitates a favorable DSPC surface density on LNPs, which moderates interactions with serum proteins like ApoE, thereby reducing rapid hepatic clearance and promoting extrahepatic delivery. In vaccine applications, CL15F 7-5 LNPs encapsulating SARS-CoV-2 RBD mRNA elicited robust anti-RBD IgG titers and neutralizing antibodies in mice, outperforming the clinically benchmarked SM-102 lipid. The piperidine headgroup further contributes to storage stability by minimizing the generation of aldehyde impurities that can form mRNA-lipid adducts. Consequently, CL15F 7-5 represents a versatile lipid for developing stable, spleen-targeted mRNA vaccines and therapeutics, leveraging tail-length engineering for enhanced efficacy without complex formulation changes.

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.

PyCB lipid (MeDZ) is a rationally designed zwitterionic ionizable lipid that serves as a core functional component in the novel three-component (ThrCo) lipid nanoparticle (LNP) platform. It is synthesized by covalently attaching a zwitterionic PyCB structure to the hydroxyl group of the clinically available ionizable lipid ALC-0315.Its key feature is its pH-responsive behavior. At physiological pH (~7.4), the PyCB headgroup exhibits zwitterionic properties, forming charge-assisted hydrogen bonds with water molecules (PyCB-H₂O complexes). This confers high hydrophilicity to the LNP surface, enhancing stability in aqueous environments and reducing nonspecific protein adsorption in the bloodstream. This zwitterionic surface effectively mimics and replaces PEGylated lipids, thereby avoiding PEG immunogenicity and the associated Accelerated Blood Clearance (ABC) effect upon repeated administrations.Crucially, in the acidic environment of endosomes (pH ~6.5), the PyCB group undergoes strong protonation, rapidly transforming into a cationic state (PyCB-H₃O⁺ complexes). This promotes efficient fusion with and disruption of the endosomal membrane, facilitating the escape and cytoplasmic release of encapsulated mRNA.By replacing both cholesterol and PEGylated lipids in traditional LNPs, PyCB lipid enables the redirection of LNP biodistribution from the liver to the spleen, achieving superior spleen-specific mRNA translation and enhancing antigen presentation for potent immune activation.

PL-40​​ is a ​​cardiolipin-mimetic ionizable lipid​​ engineered for high-efficiency, antibody-free mRNA delivery to T cells. PL 40 LNPs exhibit a mean particle size of ​​120 nm​​, zeta potential of ​​-5.19 mV​​, and >80% mRNA encapsulation efficiency, with excellent plasma stability (≤5% size change after 6h in serum). Cryo-TEM reveals ​​polyhedral nanoparticles​​ with phase-separated domains, while SAXS confirms tight mRNA packing (d-spacing: ​​~3 nm​​ vs. 6.64 nm in conventional LNPs). AFM demonstrates exceptional rigidity (high bending modulus), enabling T cell-selective uptake via actin-mediated endocytosis (>2× higher than ALC0315 LNPs).In primary human T cells, PL40 LNPs achieve ​​>90% transfection​​ at 0.5 μg mRNA dose and sustain >100× higher luciferase expression than benchmark lipids. When delivering circular RNA, they extend protein expression ​​>5 days​​ with superior spleen tropism (spleen:liver ratio = ​​2.63​​). Crucially, they reprogram T cells into functional CAR-Ts in vivo without antibody conjugation, evading exhaustion markers (no Tim-3/PD-1 upregulation). Therapeutically, PL40-based uPAR-targeted CAR mRNA reduces liver fibrosis (​​collagen↓50%​​, ALT↓50%) and rheumatoid arthritis severity (​​clinical scores↓60%​​) by clearing senescent cells. Humanized anti-uPAR CARs delivered via PL40 show near-complete cytotoxicity (>95%) against uPAR+ cells, underscoring clinical translatability.

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.

Moderna Lipid compound 182(Lipid 29 analogue-1) is a novel ionizable amine lipid developed by Moderna for the delivery of mRNA-based therapeutics. This lipid is part of Moderna's proprietary lipid nanoparticle (LNP) delivery platform, which is designed to encapsulate and protect mRNA, facilitate its cellular uptake, and enable efficient intracellular release. The ionizable nature of Lipid Compound 182 allows it to interact with mRNA at low pH (during LNP formulation) and release the payload in the neutral pH environment of the cytoplasm, making it a critical component of Moderna's mRNA delivery system.

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.

ATX-012 is an ionizable cationic lipid specifically designed for mRNA delivery systems. Its unique chemical structure enables key functions in lipid nanoparticle (LNP) formulations, such as facilitating mRNA encapsulation and enhancing endosomal escape for efficient intracellular delivery.

CICL-242​ is a constrained ionizable cationic lipid highlighted in patent US 20250127728A1 as a promising candidate for advanced therapeutic delivery, particularly in stem cell and gene editing applications. Its structure features a rigid amine headgroup similar to CICL-207, which likely facilitates efficient endosomal escape and reduces non-specific uptake, enhancing targeted nucleic acid delivery. Although detailed performance data is not fully disclosed in the patent, CICL-242 is explicitly synthesized and included in gene editing experimental systems (e.g., CRISPR-Cas9 workflows), suggesting its potential for high-efficiency transfection in hard-to-transfect cells​ like hematopoietic stem cells (CD34⁺). This makes it a strong candidate for ex vivo cell engineering and regenerative medicine, where precision and low off-target effects are critical. While further validation is needed to quantify its efficacy and safety profile, CICL-242 represents a strategic innovation in the lipid library for next-generation genetic therapies.

Based on the data from patent US 20250127728A1, CICL-238​ emerges as a highly promising ionizable lipid candidate, demonstrating notable advantages for targeted delivery applications. It achieves exceptional transfection efficiency—reaching approximately 90% of CICL-207's performance in splenic T-cells even at a reduced lipid ratio of 50% in LNP formulations. Additionally, CICL-238 exhibits minimal off-target expression​ in hepatocytes (<8%, comparable to CICL-207), underscoring its enhanced specificity for immune cells over liver tissues. Its optimized structure likely contributes to efficient endosomal escape and reduced Kupffer cell uptake, making it ideal for liver-related therapies​ (e.g., siRNA silencing for metabolic diseases) and potentially broadening applications to genetic medicine where precision and safety are paramount. Further validation in disease models could solidify its role as a versatile, low-toxicity alternative to benchmark lipids.

EB-Lipid is an innovatively engineered ionizable lipid designed to replace conventional PEG-lipid in mRNA vaccine formulations. Its structure comprises three key components: an Evans Blue-derived headgroup with high affinity for albumin, a tetraethylene glycol linker that enhances colloidal stability, and dual oleate tails for anchoring into lipid bilayers. This molecular design enables EB-Lipid to actively recruit endogenous albumin, forming an albumin-rich protein corona on the surface of lipid nanoparticles (LNPs). Following intramuscular administration, these albumin-bound EB-LNPs are preferentially transported through lymphatic vessels rather than entering the bloodstream, thereby avoiding hepatic accumulation and associated hepatotoxicity risks.Experimental data demonstrate that EB-LNPs achieve significantly higher accumulation in lymph nodes, where they are efficiently internalized by dendritic cells via albumin receptor-mediated endocytosis (e.g., gp60). This process enhances antigen presentation and activates robust cellular and humoral immune responses. In both tumor models (B16-OVA and HPV-associated) and infectious disease models (H1N1 and SARS-CoV-2 Omicron), EB-LNP-based mRNA vaccines elicited potent cytotoxic T-cell activation and durable neutralizing antibody production at low doses. Unlike traditional PEG-LNPs, EB-LNPs show minimal liver distribution, reduced immunogenicity, and improved safety profiles after repeated administrations.By leveraging albumin’s natural trafficking pathway, EB-Lipid represents a transformative delivery platform that combines targeted lymph node delivery with enhanced biosafety, positioning it as a promising candidate for next-generation mRNA vaccines and therapeutics.

GL5 is an ionizable guanidine-based lipid nanoparticle (G-LNP) designed for superior mRNA delivery. Its guanidinocarbonyl-pyrrole (GCP) headgroup enables pH-responsive behavior and strong mRNA binding via bidentate hydrogen bonds. The cholesterol-free GL5-3 formulation forms compact, stable nanoparticles (~90-120 nm) that exhibit excellent spleen-targeting capability after intravenous injection.GL5-LNPs efficiently deliver mRNA to antigen-presenting cells (APCs), enhancing antigen presentation and T cell activation. In cancer immunotherapy models, GL5-based mRNA vaccines provided complete tumor protection and induced durable immune memory. The platform also enables mRNA delivery to other organs like the pancreas via different administration routes, demonstrating remarkable versatility and therapeutic potential.

(4S)-KEL12​​ is a novel, biodegradable ionizable lipid developed for advanced mRNA vaccine delivery. It was rationally designed by incorporating both a ketal group in the linker and ester segments in the hydrophobic tails, a dual-degradable strategy aimed at enhancing its safety profile. Through iterative optimization, (4S)-KEL12 was identified as a lead candidate with an optimal pKa value of approximately 6.78, which is crucial for efficient mRNA encapsulation and endosomal release.

DORI, N-(2-hydroxyethyl)-N,N-dimethyl-2,3-bis(oleoyloxy)propan-1-aminium bromide, is an ionizable cationic lipid with lower cytotoxicity and high transfection efficiency. Reagent grade, for research use only.

2Ac3-C18 is a unique ionizable lipid with a distinct degradable core structure：featuring 2 acrylate units and 3 amine groups—linked to a C18 alkyl chain. Its LNPs (formulated with DOPE/cholesterol/DMG-PEG2000) exhibit spleen-specific mRNA delivery in vivo.

Lipid te AA3-Dlin is a novel ionizable lipid developed for mRNA-LNP vaccines.When formulated into LNPs, te AA3-Dlin demonstrates excellent stability in serum and protects encapsulated mRNA from degradation. A key feature is its unique protein corona profile, with high ApoE abundance, which is crucial for efficient in vivo targeting, particularly to the spleen. This enables potent dendritic cell transfection, leading to enhanced antigen presentation and robust cytotoxic T-cell responses for superior antitumor immunity.

304O13 is a novel Biodegradable lipidoid for RNA delivery.

ARV-T1 is a novel ionizable lipid featuring a cholesterol moiety incorporated in its tail, designed to enhance mRNA delivery efficiency. With a pKa of 6.73, it exhibits optimal pH-dependent ionization for endosomal escape and mRNA release. Structurally, ARV-T1 contains a tertiary amine head group and ester-linked lipid tails, enabling rapid in vivo metabolism and improved biocompatibility.Compared to SM-102 (used in Moderna's vaccine), LNPs formulated with ARV-T1 demonstrate superior physicochemical properties: smaller particle size (~80 nm vs. 90 nm), lower polydispersity index (0.09 vs. 0.10), and higher absolute zeta potential (-10 mV vs. -5 mV). These characteristics correlate with >90% mRNA encapsulation efficiency and enhanced stability, maintaining performance for 12 weeks at -20°C.In vitro, ARV-T1 LNPs showed 7-fold higher protein expression than SM-102 LNPs. In vivo, they prolonged luciferase expression (>72 hours vs. <48 hours for SM-102) and induced 10-fold higher neutralizing antibodies against SARS-CoV-2 spike protein at low doses. The cholesterol tail promotes endosomal membrane fusion, while ester linkages facilitate metabolic clearance, yielding an excellent safety profile in toxicity studies. This combination of efficacy and safety positions ARV-T1 as a promising platform for mRNA vaccines and therapeutics.