Tumor-Targeted Codelivery of CpG and siRNA by a Dual-Ligand-Functionalized Curdlan Nanoparticle.

The simultaneous delivery of CpG oligonucleotide along with short interfering RNA (siRNA) has the potential to significantly boost the anticancer impact of siRNA medications. Our previous research demonstrated that Curdlan nanoparticles functionalized with adenosine are capable of selectively delivering therapeutic siRNA to cancerous cells through endocytosis mediated by adenosine receptors. Herein, we synthesized a dual-ligand-functionalized Curdlan polymer (denoted by CuMAN) to simultaneously target tumor cells and tumor-associated macrophages (TAMs). CuMAN nanoparticles containing CpG and siRNA demonstrated enhanced uptake by B16F10 tumor cells and bone marrow-derived macrophages, which are facilitated by AR on tumor cells and mannose receptor on macrophages. This led to increased release of pro-inflammatory cytokines in both in vitro and in vivo settings. The synergistic effect of CpG on TAMs and RNAi on tumor cells mediated by the CuMAN nanoparticle not only suppressed the tumor growth but also strongly inhibited the lung metastasis. Our findings indicate that the CuMAN nanoparticle has potential as an effective dual-targeting delivery system for nucleic acid therapeutics.

Astrocyte-targeted siRNA delivery by adenosine-functionalized LNP in mouse TBI model.

Traumatic brain injury (TBI) induces pro-inflammatory polarization of astrocytes and causes secondary disruption of the blood-brain barrier (BBB) and brain damage. Herein, we report a successful astrocyte-targeted delivery of small interfering RNA (siRNA) by ligand functionalized lipid nanoparticles (LNPs) formulated from adenosine-conjugated lipids and a novel ionizable lipid (denoted by Ad4 LNPs). Systemic administration of Ad4 LNPs carrying siRNA against TLR4 to the mice TBI model resulted in the specific internalization of the LNPs by astrocytes in the vicinity of damaged brain tissue. A substantial knockdown of TLR4 at both mRNA and protein levels in the brain was observed, which led to a significant decrease of key pro-inflammatory cytokines and an increase of key anti-inflammatory cytokines in serum. Dye leakage measurement suggested that the Ad4-LNP-mediated knockdown of TLR4 attenuated the TBI-induced BBB disruption. Together, our data suggest that Ad4 LNP is a promising vehicle for astrocyte-specific delivery of nucleic acid therapeutics.

Tumor targeted siRNA delivery by adenosine receptor-specific curdlan nanoparticles.

Aminated curdlan derivatives are highly effective nucleic acid carriers. Previously, we proved that the ligand-functionalized curdlan derivatives have greatly enhanced cell type specificity induced by receptor-mediated internalization in vitro. In this study, to improve biocompatibility and enhance tumor-targeting efficacy of the curdlan derivative, we pegylated the adenosine functionalized amino curdlan derivative (denoted by pAVC polymer). We confirmed that the uptake of pAVC polymer carrying siRNA by tumor cells was adenosine receptor (AR)-dependent and was specifically inhibited by AMP but not by GMP. The pAVC polymers not only preserved the receptor recognition and exhibited significantly decreased cytotoxicity but also showed remarkable tumor targeting efficiency in vivo. The nanoparticles formulated from siRNA (against STAT3) and pAVC4 polymer, which bears the highest degree of PEG substitution, delivered siRNA highly specifically to tumor tissue, knocked down STAT3, and inhibited tumor growth. The pAVC polymers may be a promising carrier for tumor specific delivery of nucleic acid drugs.

Antibody responses to mRNA versus non-mRNA COVID vaccines among the Mongolian population.

Background: A nationwide vaccination program against coronavirus disease 2019 (COVID-19) was started in Mongolia 4 months after the first local transmission, which occurred in November 2020. Previous studies have reported that two doses of COVID-19 vaccine result in increased antibody against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A study was conducted in Mongolia 2 weeks after the second vaccine dose. In the present study, the serum levels of antibodies of individuals 6 months after natural SARS-CoV-2 infection were compared with those of individuals who had not been infected or had been infected but had received two doses of vaccine, including BNT162b2, ChAdOx1 n-CoV-19, Gam-COVID-Vac, and BBIBP-CorV, which were used for COVID-19 in Mongolia. Methods: Of the 450 participants in this study, 237 (52.66%) were female and 213 (47.33%) were male. Four hundred people with or without SARS-CoV-2 infection who received two doses of 4 different COVID-19 vaccine participated in the vaccine groups and vaccine plus SARS-CoV-2 infection groups (50 in each group) and 50 individuals previously infected with SARS-CoV-2 participated in the unvaccinated group. Total antibody against SARS-CoV-2 infection, anti-SARS-CoV-2 N and S protein human IgG, and antibody inhibiting RBD-ACE2 binding were tested. Results: In the BNT162b2 vaccine group, total antibody against SARS-CoV-2 remained constant until 6 months, while the other vaccine groups showed a significant decrease, as compared to the unvaccinated group. The level of anti-SARS-CoV-2 S-RBD protein IgG was significantly increased in the ChAdOx1 n-CoV-19, Gam-COVID-Vac, and BNT162b2 vaccines groups as compared to the unvaccinated group. Participants in the BNT162b2 vaccine group had higher ACE2 inhibition efficiency compared to the other vaccine groups as well as the unvaccinated group. Conclusions: The BNT162b2 vaccine showed the highest level of antibody against SARS-CoV-2, followed by the BBIBP-CorV, Gam-COVID-Vac, and ChAdOx1 n-CoV-19 vaccines. The level of antibodies was increased in people infected with SARS-CoV-2 after vaccination, as compared to uninfected but vaccinated individuals.

Analysis and identification of key anti-inflammatory molecules in Eerdun Wurile and exploration of their mechanism of action in microglia.

Ethnomedicine Eerdun Wurile (EW) can significantly promote poststroke neuro-recovery through modulation of microglia polarization. Fraction 4-6 (F4-6) isolated from EW via serial fractionation inhibits the expression of pro-inflammatory genes in LPS stimulated microglia. However, the key active molecules of F4-6 have not been identified. Herein, we identified alantolactone (Ala) and dehydrodiisoeugenol (Deh) as the active anti-inflammatory components of F4-6 by UPLC-qTof MS analysis. We confirmed that, F4-6, Ala, Deh and mixture of Ala and Deh (Mix) downregulate the expression of several pro-inflammatory genes including Ccl2, Cox2 and Il6 in LPS-treated microglia in a similar pattern. At the same time upregulate the expression of anti-inflammatory genes including Hmox1, Tgfß, Igf1 and Creb1. Moreover, the conditioned culture media obtained from F4-6 treated microglia significantly enhanced proliferation of N2a cells, and promoted neurite outgrowth possibly through upregulation of Nefh and Dlg4. Mechanistically, F4-6 strongly downregulated the expression of NF-κB p65, while also inhibiting the nuclear translocation of p65, leading to the suppression of transcription of pro-inflammatory genes initiated by NF-κB. Collectively, our data identified and quantified the key chemicals of EW and provide insights into the optimization of the herbal composition for neuroprotection.

Effect of the array of amines on the transfection efficiency of cationic peptidomimetic lipid molecules into neural cells.

The amino groups in the head group of a cationic lipid play a determinative role regarding the nucleic acid delivery efficiency of the LNP formulated from lipids. Herein, we designed four types of lipid bearing different amine-containing branched head groups to investigate the influence of type and number of amines on the neural cell targeted nuclei acid delivery. Conjugation of an ethylamino group at selected positions of a lysine-based cationic lipid resulted in 4 distinct lipids with 3 (denoted N3 lipid), 4 (denoted N4 lipid), 5 (denoted N5 lipid) and 6 (denoted N6 lipid) amino groups, respectively. Comparative analysis by flow cytometry revealed that the N3 lipid had the highest nucleic acid (plasmid and siRNA) transfection efficiency to neural cell lines (BV2 cells and N2a cells). Furthermore, the N3 lipid mediated delivery of siRNA against Toll Like Receptor 4 (TLR4) into oxygen glucose deprivation (OGD)-treated BV2 cells resulted in remarkable silencing of TLR4, inducing alternative polarization (M2) of the cells. Collectively, our data suggest that the N3 lipid is a promising siRNA delivery agent in neural cells.

The study of ethanol extract of Epilobium angustifolium L. on blood sugar level in type II diabetic rats.

Epilobium angustifolium (EA) is well known as a traditional medicinal plant in many countries with multiple health effects. However, the chemical composition and anti-diabetic effect of EA has not been reported. In our study, the composition and anti-diabetic effects of ethanol extracts from EA in vivo and in streptozotocin (STZ)-induced type II diabetic rats were investigated. EA ethanol extracts exhibited protection effect on H2O2 induced oxidative stress damage INS-1 cells, reduce the body weight loss, blood glucose level and increase insulin level when compared with those of diabetic rats. Following 21 days of EA treatment at 9.2 and 18.4mg/kg, BW increased by 15.85% and 15.53%, respectively, which were extremely higher than diabetic group (9.50%). The fasting blood glucose level of EA 9.2mg/kg group rats significantly decreased by 60.43% and insulin level increased by 2.78 times, respectively. Corresponding to that, the fasting blood glucose level of EA 18.4mg/kg group rats decreased by 52.61% and insulin level increased by 2 times, respectively. Collectively our data suggest that ethanol extract of EA has remarkably hypoglycemic effect in type 2 diabetes and EA might be a promising functional food or medicine for T2DM treatment.

Peptidomimetic Lipid-Nanoparticle-Mediated Knockdown of TLR4 in CNS Protects against Cerebral Ischemia/Reperfusion Injury in Mice.

Ischemic stroke activates toll-like receptor 4 (TLR4) signaling, resulting in proinflammatory polarization of microglia and secondary neuronal damage. Herein, we report a novel lipid-nanoparticle (LNP)-mediated knockdown of TLR4 in microglia and amelioration of neuroinflammation in a mouse model of transient middle cerebral artery occlusion (tMCAO). siRNA against TLR4 (siTLR4) complexed to the novel LNP (siTLR4/DoGo310), which was based on a dioleoyl-conjugated short peptidomimetic (denote DoGo310), was readily internalized by the oxygen-glucose-deprived (OGD) mouse primary microglia, knocked-down TLR4, and polarized the cell to the anti-inflammatory phenotype in vitro. Systemic administration of siTLR4/DoGo310 LNPs in the tMCAO mice model resulted in the accumulation of siRNA mainly in the Iba1 positive cells in the peri-infarct. Analysis of the peri-infarct brain tissue revealed that a single injection of siTLR4/DoGo310 LNPs led to significant knockdown of TLR4 gene expression, reversing the pattern of cytokines expression, and improving the neurological functions in tMCAO model mice. Our data demonstrate that DoGo310 LNPs could be a promising nanocarrier for CNS-targeted siRNA delivery for the treatment of CNS disorders.

Physicochemical properties, immunostimulatory and antioxidant activities of a novel polysaccharide isolated from Mirabilis himalaica (Edgew) Heim.

Herbal medicines often contain bioactive polysaccharides. However, many medicinal herbs have not been explored for any active saccharides that may play key roles in their bioactivities. Herein, we extracted a novel polysaccharide from Mirabilis himalaica (Edgew) heim (denoted MHHP), a popular medicinal ingredient in traditional medicines. The structural and morphological characteristics of MHHP were measured and elucidated by high-performance gel permeation chromatography, gas chromatography connected with mass spectrometry, Fourier transform infrared and nuclear magnetic resonance spectroscopy as well as scanning electron microscopy. MHHP was homogeneous with a molecular weight of 16.1 kDa, M w/M n = 1.33, containing mainly α-d-glucan residues with (1→4)-linkage. The biological activities of MHHP upon proliferation of splenic lymphocyte, activation of related cytokine and production of nitric oxide (NO) in RAW264.7 cells were investigated in vitro. MHHP induced proliferation of mouse spleen lymphocytes and significantly promoted the secretion in TNF-α, IL-6 and NO production in RAW264.7 cells. Meanwhile, MHHP exhibited relatively low antioxidant abilities. Our data suggested that MHHP may have potential immunoregulatory and anti-inflammatory activity, with a moderate antioxidant activity.

Synthesis of PEGylated cationic curdlan derivatives with enhanced biocompatibility.

Cationic polysaccharides have shown excellent ability of nucleic acids delivery. However, cationic curdlan derivatives with high degree of amination cause damage to the cell membrane and induce considerable cytotoxicity, limiting their in vivo application. Herein, we synthesized PEGylated 6-amino-6-deoxy-curdlan derivatives containing cleavable disulfide bonds. The resulting polymers (denote 6AC-2S PEGx) not only showed high affinity to siRNA but also exhibited significantly decreased cytotoxicity and hemolysis effect, while showing remarkable in vitro transfection efficiency. In vivo study demonstrated that 6AC-2S PEG40, which had a lower LD50 value than that of 6AC-100, did not cause liver damage, as the i.v. injection of 6AC-2S PEG40 to mouse did not increase serum level of ALT/AST. Furthermore, tissue distribution results showed that 6AC-2S PEG40 successfully delivered siRNA to liver, lung and spleen. Collectively, our data confirmed that PEGylation can increase the biocompatibility of cationic curdlan derivatives, which is a promising carrier for nucleic acid therapeutics.

Oral Delivery of SARS-CoV-2 DNA Vaccines Using Attenuated Salmonella typhimurium as a Carrier in Rat.

The 2019 novel coronavirus disease (COVID-19) is the disease that has been identified as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but the prophylactic treatment of SARS-CoV-2 is still under investigation. The effective delivery of eukaryotic expression plasmids to the immune system's inductive cells constitutes an essential requirement for generating effective DNA vaccines. Here, we have explored the use of Salmonella typhimurium as vehicles to deliver expression plasmids orally. The attenuated Salmonella phoP was constructed by the one-step gene inactivation method, and plasmid-encoded the spike protein of SARS-CoV-2 was transform into the Salmonella phoP by electroporation. Western blot experiment was used for the detection of SARS-CoV-2 expression on 293T cells. Wistar rats were immunized orally with Salmonella that carried a eukaryotic expression plasmid once a week for three consecutive weeks. The ELISA was performed to measure the SARS-CoV-2 specific IgG at rat's serum samples. pSARS-CoV-2 can be successfully expression on 293T cells, and all immunized animals generated immunity against the SARS-CoV-2 spike protein, indicating that a Salmonella-based vaccine carrying the Spike gene can elicit SARS-CoV-2-specific secondary immune responses in rats. Oral delivery of SARS-CoV-2 DNA vaccines using attenuated Salmonella typhimurium may help develop a protective vaccine against SARS-CoV-2 infection.

AMP functionalized curdlan nanoparticles as a siRNA carrier: Synthesis, characterization and targeted delivery via adenosine A2B receptor.

Receptor-mediated endocytosis has been used for tissue targeted delivery of short interfering RNA (siRNA) drugs. Herein, we investigated adenosine receptor (AR) as a candidate for receptor-mediated siRNA internalization. We synthesized adenosine functionalized cationic curdlan derivatives (denote CuAMP polymers). One of these polymers, CuAMP4, efficiently delivered siRNA to breast cancer cells expressing high level of A2B receptor. The internalization of siRNA loaded CuAMP4 by cancer cells was inhibited by free AMP as well as endocytosis inhibitors. Moreover, knockdown of A2BR by siRNA, or pre-treatment of the cells with anti-A2BR antibody, strongly inhibited the cellular uptake of CuAMP4. Our findings confirmed that A2BR can be utilized for cell type specific siRNA delivery, and CuAMP4 NP may be a promising delivery system for cancer cell targeted delivery of therapeutic siRNAs.

The extract of black cumin, licorice, anise, and black tea alleviates OVA-induced allergic rhinitis in mouse via balancing activity of helper T cells in lung.

BACKGROUND: A formulation of black cumin (Nigella sativa L.), licorice (Glycyrrhiza glabra L.), anise (Pimpinella anisum L.) and tea (Camellia sinensis (L.) Kuntze) (denoted BLAB tea) is traditionally used to relief allergy reaction including allergic rhinitis. However, little is known about its underlining mechanism of anti-allergic effects. METHODS: To investigate the anti-allergenic mechanism of BLAB tea, we treated ovalbumin (OVA)-induced allergic rhinitis (AR) model of mice with BLAB tea, and elucidated its possible mechanism of action. Mice in the control group were treated with phosphate-buffered saline only. Subsequently, the infiltration of different inflammatory cells was measured. In addition, histopathological changes in the nasal mucosa, and the levels of allergen-specific cytokines and OVA-specific immunoglobulins were measured. RESULTS: The aqueous extract of BLAB significantly alleviated the nasal symptoms and reduced the accumulation of inflammatory cells in the nasal mucosa and nasal lavage fluid of AR model of mice. CONCLUSION: The aqueous extract of BLAB induced the production of Th1 and Treg cytokines and inhibited the release of Th2 cytokines and histamine in nasal mucosa and serum of mice while decreasing the serum levels of OVA-specific IgE, IgG1, and IgG2a. These results suggest the potential of the aqueous extract of BLAB as a treatment option for allergic diseases.

Synergistic Regulation of Microglia Gene Expression by Natural Molecules in Herbal Medicine.

The activated microglia contribute to stroke-induced neuroinflammation by upregulating the expression of a pleura of genes that are characterized as either proinflammatory or anti-inflammatory. The natural products alantolactone (Ala) and dehydrodiisoeugenol (Deh) found in Inula helenium L. and Myristica fragrans Houtt., respectively, are regularly used in traditional herb medicine, which play anti-inflammatory and antioxidant roles via regulation of canonical pathways such as nuclear factor kappa B (NF-κB) in microglia and microphages. To illustrate the full spectra of gene expression alteration in microglia treated with Ala, Deh, and the mixture of Ala and Deh (denoted as Mix), we performed RNA-seq analysis of total RNA extracted from lipopolysaccharide- (LPS-) treated microglia subsequently exposed to Ala, Deh, and Mix. While both chemicals regulated the gene expression that facilitates an anti-inflammatory polarization, the mixture exerted some distinctive synergic regulatory effect, which differed from either of the chemicals alone. Our data provide important evidence for further research on the therapeutic mechanism of traditional medicine including Eerdun Wurile (EW).

Oxidized curdlan activates dendritic cells and enhances antitumor immunity.

Curdlan activates dendritic cells (DCs) and enhances DC-based antitumor immunity. However, hydrophobicity and heterogeneity of curdlan particulates hinder perfect binding of curdlan to dectin-1 receptor, resulting in the reduced activation of antigen presenting cells and limited antitumor effects. Herein, we synthesized partially oxidized curdlan derivative (ß-1,3-polyglucuronic acid, denote PGA). PGA-45 polymer, the reaction product prepared from curdlan by oxidation with 4-acetamido-TEMPO/NaClO/NaClO2 systems under acid conditions for 45 min, activated DCs, induced the expression of co-stimulatory molecules and cytokines, and promoted allogenic T cell proliferation as well as the expression of IL-2. Mechanistically, PGA-45 polymer strongly enhanced phosphorylation of IKK-ß and reduced the expression of phosphorylated Akt, suggesting that PGA-45 may activate multiple cell surface receptors such as TLR4 and dectin-1. Administration of tumor lysate pulsed DCs pre-treated with PGA-45 particles induced strong antitumor activity in B16F10 melanoma model. Our data suggest that PGA-45 have strong adjuvant effects for anti-cancer immunity and the design of PGA polymers may provide insights in the development of novel adjuvants for cancer immunotherapy.

Regulation of microglia polarization via mannose receptor-mediated delivery of siRNA by ligand-functionalized DoGo LNP.

The pro-inflammatory polarization of microglia after stroke is one of the major causes of secondary brain injury. Downregulation of the gene involved in canonical inflammatory pathways in glial cells can exert neuroprotective effects via inhibiting the release of pro-inflammatory factors. In this study, we functionalized DoGo lipids with mannose, the ligand of the mannose receptor (MR) that is expressed in microglia, and evaluated the MR-mediated cellular internalization of DoGo lipid nanoparticles (denote M3) carrying siRNA against TLR4 in BV2 cells in vitro. We confirmed that siTLR4/M3 complexes were specifically internalized by BV2 cells in a MR-dependent manner, and the treatment of oxygen glucose deprivation (OGD)-treated BV2 cells with siTLR4/M3 complexes resulted in remarkable silencing of TLR4, and induced downregulated M1 polarization and upregulated M2 polarization markers. Collectively, our data suggest that the M3 lipoplex is a promising microglia-targeting siRNA delivery agent.

Size-Independent Transmembrane Transporting of Single Tetrahedral DNA Nanostructures.

DNA nanostructures have attracted considerable attention as drug delivery carriers. However, the transmembrane kinetics of DNA nanostructures remains less explored. Herein, the dynamic process of transporting single tetrahedral DNA nanostructures (TDNs) is monitored in real time using a force-tracing technique based on atomic force microscopy. The results show that transporting single TDNs into living HeLa cells need ≈53 pN force and ≈25 ms duration with the average speed of ≈0.6 µm s-1. Interestingly, the dynamic parameters are irrelevant to the size of TDNs, while the larger TDNs rotated slightly during the transporting process. Meanwhile, both the results from single-molecule force tracing and ensemble fluorescence imaging demonstrate that the different size TDNs transmembrane transporting depends on caveolin-mediated endocytosis.

Analysis and Identification of Tumorigenic Targets of MicroRNA in Cancer Cells by Photoreactive Chemical Probes.

Photoactive RNA probes have unique advantages in the identification of microRNA (miR) targets due to their ability for efficient conjugation to the target sequences by covalent crosslinking, providing stable miR-mRNA complexes for further analysis. Here, we report a highly efficient and straightforward method for miR target identification that is based on photo-reactive chemical probes and RNA-seq technology (denotes PCP-Seq). UV reactive probes were prepared by incorporating psoralen in the specific position of the seed sequence of miR. Cancer cells that were transfected with the miR probes were treated with UV, following the isolation of poly(A) RNA and sequencing of the transcriptome. Quantitative analysis of RNA-seq reads and subsequent validation by qPCR, dual luciferase assay as well as western blotting confirmed that PCP-Seq could highly efficiently identify multiple targets of different miRs in the lung cancer cell line, such as targets PTTG1 and PTGR1 of miR-29a and ILF2 of miR-34a. Collectively, our data showed that PCP-Seq is a robust strategy for miR targets identification, and unique in the identification of the targets that escape degradation by miRISC and maintain normal cellular level, although their translation is repressed.

Modulation of Microglia Polarization through Silencing of NF-κB p65 by Functionalized Curdlan Nanoparticle-Mediated RNAi.

Microglia polarization plays an important role in poststroke recovery. Inhibition of proinflammatory (M1) polarization and promotion of anti-inflammatory (M2) polarization of microglia are potential therapeutic strategies for inflammation reduction and neuronal recovery after stroke. Here, we evaluated the central nervous system (CNS)-targeted short interfering RNA (siRNA) delivery ability of functionalized curdlan nanoparticles (CMI) and investigated the nuclear factor-κB (NF-κB) p65 silencing efficiency of CMI-mediated siRNA in microglia, as well as the resulting neuroprotective effect of microglia polarization and neuroprotection in vitro and in vivo. The systemic delivery of NF-κB p65 siRNA (sip65) complexed to CMI nanoparticles in the mouse model of transient middle cerebral artery occlusion (tMCAO) resulted in the distribution of siRNA in microglia and significant silencing in NF-κB p65 in the peri-infarct region. Knockdown of NF-κB p65 resulted in M1 to M2 phenotypic transition of microglia, evidenced by the change in the expression pattern of signature cytokines as well as inducible nitric oxide synthase and CD206. Moreover, the CMI-mediated silencing of p65 increased the density of neurons and decreased pyknosis and edema in the peri-infarct region. Assessment of the neurological deficit score on the Bederson scale revealed a significantly reduced score in the mouse model of tMCAO treated with the sip65/CMI complex. Collectively, our data suggest that CMI nanoparticles are a promising CNS-targeting siRNA delivery system, and NF-κB p65 may be a potential therapeutic target for inflammation reduction and poststroke recovery.

Silencing of STAT3 via Peptidomimetic LNP-Mediated Systemic Delivery of RNAi Downregulates PD-L1 and Inhibits Melanoma Growth.

Cutaneous melanoma is the most aggressive skin cancer with notorious drug resistance. Inhibition of immune checkpoint molecules is one of the most promising approaches for cancer therapy. Herein, we show that RNAi mediated silencing of STAT3 expression in the tumor tissue robustly inhibit tumor growth in B16F10 mouse model of melanoma. We designed a peptidomimetic-based lipid nanoparticles (LNPs) for the delivery of siRNA in mouse model of melanoma. When systemically administered, the novel formulation (denote DoCh) preferentially delivered siRNA to the tumor tissue. Remarkably, sequential intravenous injections of siRNA against STAT3 induced profound silencing of STAT3 expression in tumor tissue, which resulted in significant downregulation of PD-L1, leading to significant inhibition of tumor growth through inhibition of tumor immune checkpoint. Moreover, DoCh-mediated siRNA delivery did not show noticeable damage to the major organs. Collectively, our data demonstrated that DoCh LNP is a promising tumor-targeted siRNA delivery system.