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.

306Oi10 is a branched-chain ionizable lipidoid and may be useful in the generation of lipid nanoparticles (LNPs). 306Oi10 ionizable lipids tail is isodecyl acrylate, affording the lipid tail a carbon branch, which confers significant improvement of the mRNA deliver efficiency. Compared with the straight-tailed 306O10, the 306Oi10 with carbon branches at the lipid tail generates more powerful surface ionization at late endosomal pH of 5.0 to improve the delivery efficiency of mRNA. The studies showed that 306Oi10 iLNPs significantly promoted mRNA expression in liver (more than 10- fold).306Oi10 iLNPs could induce stronger protein expression than two benchmark lipids, C12-200 and DLin-MC3-DMA. The total organ protein expression produced by 306Oi10 iLNPs was threefold higher than MC3 and over 20-fold higher expression than C12-200. The 306Oi10 iLNPs could codeliver three distinct mRNAs (luciferase, mCherry, and erythropoietin), or deliver Cas9 mRNA and single guide RNA (sgRNA) separately. Besides, 306Oi10 iLNPs have the potential of mRNA therapy for hepatocellular carcinoma, because they could target malignant hepatocytes, endothelial cells, and Kupffer cells simultaneously. To enable 306Oi10 iLNPs to deliver mRNA to extrahepatic organs, charged phospholipids were used in place of neutral phospholipids. The substitution of DOPE with DOTAP increased the positive surface charge of iLNPs at pH 7 about fivefold and changed the protein expression ratio of liver/lung from 36:1 to 1:56. Similarly, the substitution of DOPE with PS decreased the positive charge and changed the protein expression ratio of liver/spleen from 8:1 to 1:3. Further, the lung-target of DOTAP was better than that of neutral or anionic lipids, which might reduce immune cells infiltration in the lung.

PL1 is a novel biomimetic phospholipid. PL1 nanoparticle delivery of costimulatory receptor CD137 mRNA improved the immunotherapy with an anti-CD137 Ab to some extent in both tumor models with better results obtained in the B16F10 melanoma model as compared to the A20 lymphoma model.

OF-Deg-Lin is a biodegradable lipid containing an ester group, developed from the nonbiodegradable, linoleic acid derived OF-02; mRNA-LNPs containing OF-Deg-Lin showed high expression in the spleen. The ionizable lipid Of-Deg-Lin was synthesized, which possessed the similar chemical structure with OF-02.Both Of-Deg-Lin and OF-02 had diketopiperazine core and doubly unsaturated tails, and the difference between them was that Of-02 contained nondegradable 1,2-amino-alcohol linkages, whereas Of-Deg-Lin contained degradable ester linkages The change of linker altered iLNPs distribution and mRNA expression in vivo. Although the Of-Deg-Lin iLNPs could accumulate in the liver and spleen, they induced the expression of most functional proteins in B lymphocytes of spleen (over 85% of the total protein), not in the liver. Of-Deg-Lin iLNPs can deliver mRNA and express functional proteins in the spleen specifically, but the mechanism is unclear.

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

A18-Iso5-2DC18 that could not only deliver mRNA vaccines robustly but also activate the stimulator of interferon genes (STING) pathway. A18-Iso5-2DC18 strongly binds to the stimulator of interferon genes (STING) and induces potent cytolytic T lymphocyte responses, resulting in substantial antitumor immunity (Miao et al. 2019).

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.

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.

C24-Ceramide is a sphingolipid that can be used for the lipid membranes composed. C24-Ceramide induces time-dependent changes in membrane properties. C24-Ceramide induces membrane reorganization.

TriGalNAc CBz is a GalNAc derivative and tri-GalNAc is an asialoglycoprotein receptor (ASGPR) ligand. TriGalNAc CBz can be used for mRNA drug delivery as well as lysosomal targeted chimerism (LYTAC) studies.

L202 is a novel ionizable lipid for RNA delivery.

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.

ATX-001 is a novel ionizable cationic lipid compound for RNA delivery.

A12-Iso5-2DC18 is a novel amine containing lipid can be used for mRNA delivery, activate the stimulator of interferon genes (STING) pathway, and exhibit anti-tumor immunity.

ATX-081 is a novel ionizable lipid for rna delivery.

ATX-083 is a novel ionizable lipid for rna delivery.

ATX-084 is an ionizable cationic lipids for RNA or Gene delivery.

ATX-087 is a novel ionizable lipid for rna delivery.

304O13 is a novel Biodegradable lipidoid for RNA delivery.

CSL3 is a novel cationic switchable lipid, pH-triggered molecular switch for siRNA delivery.In vivo factor VII silencing efficiency of the CSL3-based formulations was compared to that of the CSL4-based formulation (Fig. 5E). CSL3-based LNP were found to demonstrate a dose–response knockdown, resulting in significant silencing efficacy (∼50% silencing) at 1 mg kg−1.These results confirm the crucial role of the pH-sensitive conformational change of CSL3 in the in vivo transfection efficacy, in agreement with the in vitro results. The in vivo silencing efficacy of the CSL3 LNP may be further improved by lowering the molar percentage of DMG-PEG2000 in the formulation11,33 or by using combinatorial approaches to enhance the potency of the CSL3 lipid structure as well as the blood stability of the LNP (currently under investigation).

Fomivirsen (ISIS-2922 free base) is an antisense 21 mer phosphorothioate oligonucleotide. Fomivirsen is an antiviral agent that is used cytomegalovirus retinitis (CMV) research, incluiding in AIDs. Fomivirsen binds to and degrades the mRNAs encoding CMV immediate-early 2 protein, thus inhibiting virus proliferation.

DSPE-SPDP is a phospholipid molecule. DSPE-SPDP can orient itself to form lipid bilayer in water. DSPE-SPDP can be used for the research of various biochemical.