Compound 22, as detailed in United States Patent US 2026/0014089 A1, is a bifunctional ionizable lipid engineered for precision drug delivery. Its structure integrates a monosaccharide targeting headgroup, designed to bind specifically to DC-SIGN receptors on dendritic cells, via a sophisticated linker connected to a biodegradable lipid anchor. This design enables it to serve as a key component of lipid nanoparticles (LNPs), forming a targeted delivery system. By leveraging the specific carbohydrate-receptor interaction, these LNPs are preferentially internalized by dendritic cells, critical for initiating adaptive immune responses. In vivo studies from the patent, such as the biodistribution data shown in Figure 5, confirm effective accumulation in lymphoid tissues like the spleen and lymph nodes. Consequently, this targeted delivery enhances the potency of encapsulated payloads (e.g., mRNA vaccines) by ensuring professional antigen presentation, eliciting a stronger and more specific immune response—evidenced by higher neutralizing antibody titers—making it a powerful tool for next-generation vaccines and therapeutics.

BHD-C2C2-PipZ, as an efficient ionizable cationic lipid, achieves high encapsulation efficiency and controllable release of mRNA through its unique chemical structure. In PEG-free 3P-LNPs, its electrostatic interaction with tripolyphosphate successfully replaces the steric stabilization effect of traditional PEG, offering a new strategy to circumvent PEG immunogenicity. Its hepatic distribution pattern further indicates that LNP design should take into account the heterogeneity of the organ microenvironment.

TE AA3-Dlin is an optimized lipid nanoparticle (LNP) carrier designed for mRNA-based cancer immunotherapy, enabling precise in vivo dendritic cell (DC) reprogramming to enhance antitumor immunity. TE AA3-Dlin LNP exhibits superior serum stability, maintaining consistent particle size and low turbidity under physiological conditions, while protecting mRNA from degradation, which is crucial for effective delivery. Functionally, TE AA3-Dlin preferentially targets splenic DCs by leveraging ApoE-enriched protein coronas, facilitating efficient cellular uptake and mRNA expression, as demonstrated by enhanced EGFP signals in DCs.This targeting promotes DC maturation, antigen presentation, and membrane-bound IL-15 expression, activating cytotoxic T lymphocytes (CTLs) for tumor rejection. In models like melanoma and colon carcinoma, it synergizes with checkpoint inhibitors, showing minimal toxicity and robust immunological memory.

AP60 is a novel, biomimetic ionizable lipid, identified as the lead compound from a library of 67 aminophosphonate-derived lipids. Inspired by the structure of natural phospholipids, it forms the core component of lipid nanoparticles within the CROSS delivery platform. AP60-based LNPs demonstrate superior efficiency in delivering mRNA and circular RNA to neuronal cells and astrocytes compared to the clinically used MC3 LNP. In a mouse model of spinal cord injury, AP60 LNPs achieved significantly higher protein expression at the lesion site (13.7-fold locally, 4.6-fold intravenously) while concurrently reducing off-target accumulation in the liver by nearly 5-fold. This indicates improved targeting to the central nervous system injury site and a potentially better safety profile. Its cellular uptake is primarily mediated by clathrin-mediated endocytosis and macropinocytosis, followed by efficient endosomal escape. By encapsulating therapeutic circular RNAs encoding Sox2, Ascl1, and GDNF, AP60 LNPs enable effective in vivo reprogramming and neuroprotection, leading to significant functional recovery of bladder and locomotor functions after spinal cord injury.

AX6​​ is an ionizable lipid in the ​​F32 LNP​​ formulation, engineered by ReNAgade/Orna Therapeutics for targeted mRNA delivery to T cells. AX-6's unique ​​bridged bicyclic/polycyclic core​​ with a ​​tertiary amine group​​ enables pH-dependent protonation and endosomal escape, while ​​C14-C18 hydrophobic tails​​ (optionally branched/fluorinated) enhance bilayer stability and mRNA encapsulation. Demonstrating ​​exceptional T-cell tropism​​, AX6 achieves high transfection efficiency in CD4+/CD8+ T cells (validated in NHP/humanized models) with minimal toxicity. Compared to clinical benchmarks (SM-102, ALC-0315), its rigid core offers superior ​​serum stability​​ and ​​immune-cell specificity​​, positioning it as an ideal candidate for ​​CAR-T/NK therapies​​ and ​​next-gen vaccines​​. The F32 LNP system's proven efficacy (e.g., in vivo B-cell depletion) underscores AX 6's transformative potential for ​​cell engineering​​ and ​​immunotherapies​​.

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.

C14-306 is a rationally designed ionizable lipid for brain targeting delivery, characterized by a linear 3,3'-diamino-N-methyldipropylamine (306) core conjugated with tetradecyl (C14) tails. This specific architectural configuration, synthesized via epoxide ring-opening amination, yields a molecular structure that optimally balances hydrophobic character and protonation capacity. The C14 alkyl chains enhance membrane integration and LNP stability, while the multiamine core facilitates efficient mRNA complexation and pH-dependent endosomal disruption. When formulated into LNPs with standard helper lipids (DOPE, cholesterol, DMG-PEG2000), C14-306-based nanoparticles exhibit favorable physicochemical properties, including a monodisperse size distribution near 110 nm and high mRNA encapsulation efficiency (>84%). High-throughput in vivo barcoding screening identified C14-306 LNPs as lead candidates for brain delivery, demonstrating a significant tropism for neuronal cells over liver tissue. In validation studies, LNPs incorporating C14-306 achieved a 6.9-fold increase in luciferase mRNA transfection in the mouse brain compared to the SM-102 benchmark, coupled with a substantial reduction in hepatic off-target expression. Flow cytometry confirmed preferential transfection of NeuN+ neurons, and safety assessments indicated no significant blood-brain barrier compromise or induction of systemic inflammation. The efficacy of C14-306 is attributed to its tailored pKa, promoting extended circulation and enhanced endosomal escape within brain cells. C14-306 represents a promising platform for systemic mRNA therapeutics targeting neurological disorders.

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.

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.

A33-D268 is an ionizable lipid derived from a 2-aminoimidazole (AM) core, featuring an asymmetric hydrophobic tail structure designed to optimize mRNA interactions. Selected as the top candidate from a 21-lipid library through molecular dynamics (MD) simulations, it demonstrated superior performance: low root mean square deviation (RMSD) and the smallest radius of gyration (Rg), indicating tight mRNA compaction, alongside moderate electrostatic energy and above-average hydrogen bonding for stable encapsulation. Formulated into LNPs, it achieves ​​efficient muscle-specific transfection​​ post-intramuscular injection, rivaling commercial ALC-0315 LNPs. Crucially, it exhibits ​​29-fold lower hepatic off-target expression​​, attributed to its inability to leverage serum protein coronas for liver tropism.

AA76-lipid is a dipeptide-modified ionizable lipid, engineered with an arginine-histidine motif, that constitutes the core of the pancreatic-targeted AH-LNP delivery platform. Its chemical architecture, characterized by an externally positioned and C-terminally modified arginine residue, was identified through systematic screening as the optimal structure for function. Upon intraperitoneal administration, AH-LNPs formulated with this lipid interact with proteins in the peritoneal fluid, undergoing dynamic assembly into significantly larger complexes. This substantial increase in size (from ~100 nm to over 360 nm) exploits a physical targeting principle termed the Capsule-filter-mediated pancreatic targeting (CAMP) mechanism. Large particles are selectively filtered out by the dense capsules of other abdominal organs, leading to preferential enrichment in the capsule-deficient pancreas. Concurrently, the arginine-histidine motif directs the formation of a distinct protein corona enriched with apolipoproteins (e.g., APOE, APOB-100), which mimics very-low-density lipoprotein (VLDL). This corona enables efficient cellular internalization primarily into pancreatic stromal cells via VLDL receptor (VLDLR)-mediated endocytosis, known as the VMP pathway. The synergistic integration of the physical CAMP targeting and the biological VMP uptake mechanisms empowers AA76-lipid-based AH-LNPs to achieve highly specific, potent, and sustained mRNA delivery and gene editing within the pancreas across multiple species, demonstrating exceptional therapeutic efficacy in models of both autoimmune pancreatitis and pancreatic cancer.

H5T5 is a leading ionizable lipid nanoparticle (LNP) formulation optimized for in vivomRNA delivery, featuring a pKa of 6.51, a size of ~154 nm, and a narrow polydispersity index (PDI) of 0.05. It demonstrated superior in vitromRNA transfection efficiency in primary immune cells, such as bone marrow-derived macrophages. Following intravenous administration, H5T5 exhibits precise organotropism, predominantly targeting the spleen and bone marrow, where it effectively delivers mRNA to a broad spectrum of immune cells, including macrophages, dendritic cells, T cells, B cells, and NK cells. This capability enables its core application: the in vivogeneration of "pan-CAR" immune cells. When loaded with anti-HER2 CAR mRNA, the H5T5-based therapy achieved potent tumor regression and prolonged survival in multiple solid tumor models. Preliminary safety assessments indicated a manageable cytokine profile and no significant organ toxicity, positioning it as a promising platform for in vivocell engineering.

Lipid 2298 is a novel ionizable lipid developed by Sai Biomedicine demonstrates excellent performance with a spleen-to-liver ratio of 3.448​ and a very high total expression level of 2.4E+07. Lipid 2298 offers a strong balance of efficient systemic protein production and clear preferential delivery to the spleen.

Lipid 2310 is a novel ionizable lipid developed by Sail Biomedicine demonstrates excellent performance with a spleen-to-liver ratio of 5.58 and a very high total expression level of 1.3E+07. Lipid 2310 offers a strong balance of efficient systemic protein production and clear preferential delivery to the spleen.

CICL-242​ is a constrained ionizable cationic lipid highlighted in patent US 20250127728A1 developed by Capstan 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.

Lipid 2306 is a novel ionizable lipid developed by Sail Biomedicine demonstrates excellent performance with a spleen-to-liver ratio of 3.68 and a very high total expression level of 2.5E+07. Lipid 2306 offers a strong balance of efficient systemic protein production and clear preferential delivery to the spleen.

Lipid OC7, as described in the patent WO2022207938A1, is a novel ionizable lipid that serves as the core functional component of the saNppa-LNP delivery system. Its key innovation lies in its unique biodegradable structure featuring an internal ester bond. Under typical physiological conditions, this bond hydrolyzes, triggering a charge shift from a cationic form that complexes nucleic acids to a zwitterionic form that releases them. This property is central to its role in enabling long-acting self-amplifying RNA (saRNA) therapies. Specifically, OC7 facilitates immune stealth by mitigating early interferon responses, supports sustained and efficient intracellular replication of saRNA even at low doses, and enables therapeutic protein expression that persists for over 28 days from a single administration. This combination of efficient delivery, controlled release, and extended duration of action makes OC7-based LNPs a promising platform for long-term treatments, such as for myocardial infarction, as demonstrated in the referenced research.

​​Lipid 10a-26​​ is an ionizable lipid developed by Orna Therapeutics for lipid nanoparticle (LNP) formulations. Lipid 10a-26 is a key ionizable lipid in the LNP-6 formulation. Through structural modification, it exhibits reduced binding to ApoE proteins and lowered liver affinity compared to traditional ionizable lipids. Instead, Lipid 10a-26 demonstrates strong splenic tropism—in non-human primate studies, it effectively delivers payloads to the spleen and immune cells in peripheral blood, such as T cells, NK cells, and macrophages, enabling the possibility of "in vivo CAR-T" therapy. Its pKa is tuned to approximately 6.0–6.5, allowing rapid protonation in the acidic endosomal environment, which promotes endosomal membrane disruption and efficient cytosolic release of circular RNA.

98N12-5 is an ionizable cationic lipid. It has been used in combination with other lipids in the generation of lipid nanoparticles (LNPs). LNPs containing 98N12-5 and encapsulating proprotein convertase subtilisin kexin type 9 (PCSK9) siRNA selectively accumulate in the liver and reduce total serum cholesterol levels in mice and rats and serum LDL levels in cynomolgus monkeys.

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.

A28-C6B2 is an ionizable lipid (pKa 6.43) designed for mRNA encapsulation in lipid nanoparticles (LNPs). Following intravenous injection in mice, these LNPs exhibit spleen-selective accumulation, particularly localizing in F4/80+ macrophages and CD11c+ dendritic cells, with moderate uptake by T lymphocytes.

Sail Lipid 2308​ is a novel ionizable lipid targeting to spleen developed by Sai Biomedicine.As described on US20250205167A1, Lipid 2308 was designed with a ​​piperidine core​​ (6-membered ring) and asymmetric C17/C11 chains, this lipid achieves unprecedented ​​spleen-specificity​​. It demonstrates dominant spleen accumulation (Spleen RLU: ​​7.8E+06​​, 91.8% of total signal) with a record ​​spleen-to-liver ratio of 112.7​​ (9× higher than 2231). Despite lower protein expression (hEPO: 11,000 ng/mL), near-zero liver uptake (Liver RLU: 66,000) makes Lipid 2308 unparalleled for vaccine/immunotherapy applications targeting splenic immune cells.

E12CA1A3 is an ionizable cationic lipid (pKa = 6.4) that has been used in the generation of lipid nanoparticles (LNPs) for the delivery of mRNA in vitro and in vivo.1 LNPs containing E12CA1A3 and encapsulating an mRNA reporter induce luciferase reporter expression in mouse bone marrow-derived dendritic cells (BMDCs) and mice. LNPs containing E12CA1A3 are cleared more rapidly from the liver than LNPs containing DLin-MC3-DMA (Item No. 34364) in mice.

A2-Iso5-2DC18 is a top-performing lipid for mRNA delivery in bone marrow-derived dendritic cells (BMDCs), BMDMs and HeLa cells.

C14-490 is an ionizable cationic lipid (pKa = 5.94).1 It has been used in the generation of lipid nanoparticles (LNPs) for the delivery of mRNA in vivo.C14-490-containing LNPs accumulate primarily in the fetal mouse liver and, to a lesser extent, in the lungs, intestine, and brain after vitelline vein injection on gestational day 16 (E16).1 CD45-functionalized LNPs containing C14-490 and encapsulating mRNA encoding GFP transfect Jurkat cells, which constitutively express the CD45 receptor (CD45R).C14-490-containing CD45-functionalized LNPs encapsulating Cre mRNA mediate genome modulation in bone marrow hematopoietic stem cells (HSCs) for at least four months after in utero injection in R26mT/mG mice at E13.5.

LIPID168(pKa ~6.5) ​​ is an optimized ionizable lipid engineered for in vivo mRNA delivery to hematopoietic stem cells (HSCs) in bone marrow. Developed by ​​Yoltech Therapeutics​​ through high-throughput screening of lipid libraries, it features a ​​diethylamino head group​​ and a tailored hydrophobic tail structure that enables antibody-free targeting. When Lipid 168 was formulated into lipid nanoparticles (LNPs), it achieved ​​48.5% base editing efficiency​​ in bone marrow cells —surpassing benchmarks like LIPID-028 (19.7%)—and reduced off-target liver editing from 71% to 19% by incorporating ​​miR-122 target sequences​​. In humanized β-thalassemia models, LNP 168 delivered ABE8e mRNA/sgRNA to patient-derived HSCs, yielding ​​42.6% editing at the HBG promoter​​, reactivating fetal hemoglobin (γ-globin) and rescuing erythroid defects . Its bone marrow specificity is driven by a unique ​​protein corona​​ enriched in albumin, fibronectin, and fibrinogen . Safety studies confirmed transient immune responses and no cumulative toxicity . LIPID-168 represents a promising non-viral platform for curative gene therapies in blood disorders.

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.

HY-501​​ is a next-generation cationically ionizable lipid engineered for high-efficiency RNA delivery developed by Biontech. Formulated at ​​40–50 mol%​​ in lipid nanoparticles (LNPs) alongside DSPC, cholesterol, and polysarcosine-conjugated lipid ​​C14pSar23​​, HY-501 yields uniform, stable particles (80–100 nm) with >90% RNA encapsulation. It demonstrates ​​superior in vivo performance​​: driving 2-fold higher protein expression than benchmark lipids (EA-405/HY-405) in muscle tissue, minimizing off-target liver accumulation, and reducing immunogenic risks (near-zero complement activation and <5% hemolysis). Preclinically, HY-501-based LNPs encoding SARS-CoV-2 spike protein elicit potent neutralizing antibodies and T-cell responses, underscoring its utility in precision vaccines. Its combination of scalable synthesis, exceptional transfection efficiency, and biosafety establishes HY-501 as a transformative vector for therapeutic RNA delivery.

LIPID 14 is a novel ionizable lipid used for mRNA delivery.In 2021, Elia et al. used lipid 2 LNPs and lipid 14 LNPs to deliver mRNA encoding SARSCoV-2 human Fc-conjugated receptor binding domain (RBDhFc mRNA). While both lipid 274 LNP RBD-hFc mRNA and lipid 14 LNP RBD-hFc mRNA induced equal cellular and humoral responses in mice at an mRNA dose of 5 μg, only lipid 14 LNP RBD-hFc mRNA exhibited strong immunogenicity following intradermal administration. Both intradermal administration and intramuscular administration of lipid 14 LNPs could activate antigen presenting cells (APCs), thus inducing cellular responses.