Natural long-chain saturated fatty acids doped LNPs enabling spleen selective mRNA translation and potent cancer immunotherapy

Rationally tailored lipid nanoparticles(LNPs)with efficient and tunable delivery of mRNA in vivo are crucial for mRNA vaccines.Selective expression of antigenic protein in lymphoid tissues/organs could improve the immunostimulatory efficacy and safety of LNPs-based mRNA vaccines.Inspired by the metabolic behavior that long-chain saturated fatty acids tending to enter lymphoid tissue rather than the liver,we developed fatty acid-doped LNPs capable of mediating differential protein expressions in the liver and spleen when administered intravenously.When the molar ratio of saturated fatty acid located 60%–70%,the doped LNPs achieved the spleen selective mRNA translation.The mechanism could be attributed to the different cellular uptake behaviors of saturated fatty acids in hepatocytes.Immunization with a model antigen(ovalbumin)mRNA-loaded spleen selective LNPs,we observed enhanced antigen-specific T cell immune responses,and potent immunotherapeutic and immunoprophylactic efficacy in the mouse lymphoma model.Our natural long-chain saturated fatty acids metabolic characteristics-inspired design of LNPs for spleen-selective mRNA vaccines delivery will provide references for designing mRNA vaccines with high efficacy and safety for tumor immunotherapy.

PEG400-mediated nanocarriers improve the delivery and therapeutic efficiency of mRNA tumor vaccines

Dendritic cell(DC)-targeted delivery of mRNA is a prominent method to boost the efficacy of mRNA tumor vaccines.The targeting ligands are often modified on nanocarriers by polyethylene glycol(PEG)linker in mRNA delivery systems.Whether the PEG linker length influences the targeting delivery efficiency of mRNA nanocarrier in vivo remains unclear.Here,we designed and constructed DC-targeted mRNA delivery systems modified by mannose via different PEG linker lengths(100/400/1000/2000)(MPn-LPX).The top candidate MP_(400)-LPX(the linker was PEG400)showed the optimal mRNA expression and antigen presentation owing to the highly efficient uptake by DCs.Furthermore,MP_(400)-LPX could better inhibited tumor growth and extended survival in the E.G7-OVA lymphoma and TC-1 cervical tumor mouse model.Collectively,these results demonstrated that PEG400 was the optimal linker for the PEGylated DC-targeted mRNA vaccines.Our findings provided a new platform for the rational design of targeted mRNA nanovaccines with shorter-length PEG.

靶向CCL21/CCR7轴治疗肿瘤转移的研究进展

转移是肿瘤患者死亡最常见的原因,而淋巴转移是大多数肿瘤转移的主要途径之一。近年来,CC趋化因子配体21(CC chemokine ligand 21,CCL21)及其受体CC趋化因子受体7型(CC chemokine receptor type 7,CCR7)在淋巴转移中的作用逐渐受到关注。CCL21主要由淋巴内皮细胞产生,其与树突状细胞(Dendritic cells,DCs)和T细胞等表面CCR7的相互作用是免疫细胞淋巴迁移及淋巴结归巢的主要决定因素。然而,表达CCR7的肿瘤细胞也可以利用类似的机制进入淋巴管进行淋巴转移。如何靶向CCL21/CCR7轴,既能抑制淋巴转移,又不影响抗肿瘤免疫反应已成为肿瘤免疫治疗研究的重要议题。文中将对CCL21/CCR7轴在淋巴转移中的作用及其作为靶点治疗肿瘤转移的临床前和临床试验研究进行综述,为靶向CCL21/CCR7信号轴治疗肿瘤转移的相关研究提供参考。

Inhibiting collagen Ⅰ production and tumor cell colonization in the lung via miR-29a-3p loading of exosome-/liposome-based nanovesicles

The lung is one of the most common sites for cancer metastasis.Collagens in the lung provide a permissive microenvironment that supports the colonization and outgrowth of disseminated tumor cells.Therefore,down-regulating the production of collagens may contribute to the inhibition of lung metastasis.It has been suggested that mi R-29 exhibits effective anti-fibrotic activity by negatively regulating the expression of collagens.Indeed,our clinical lung tumor data shows that mi R-29 a-3 p expression negatively correlates with collagen I expression in lung tumors and positively correlates with patients’outcomes.However,suitable carriers need to be selected to deliver this therapeutic mi RNA to the lungs.In this study,we found that the chemotherapy drug cisplatin facilitated mi R-29 a-3 p accumulation in the exosomes of lung tumor cells,and this type of exosomes exhibited a specific lung-targeting effect and promising collagen down-regulation.To scale up the preparation and simplify the delivery system,we designed a lung-targeting liposomal nanovesicle(by adjusting the molar ratio of DOTAP/cholesterol-mi RNAs to 4:1)to carry mi R-29 a-3 p and mimic the exosomes.This liposomal nanovesicle delivery system significantly down-regulated collagen I secretion by lung fibroblasts in vivo,thus alleviating the establishment of a pro-metastatic environment for circulating lung tumor cells.

Core-shell lipid-polymer nanoparticles as a promising ocular drug delivery system to treat glaucoma

Nowadays,tremendous researches have been focused on the core-shell lipid-polymer nanoparticles(LPNs) due to the advantages of both liposomes and polymer nanoparticles.In this work,LPNs were applied to encapsulate brinzolamide(Brz-LPNs) for achieving sustained drug release,improving drug corneal permeation and enhancing drug topical therapeutic effect.The structure of Brz-LPNs was composed of poly(lactic-co-glycolic) acid(PLGA) nanocore which encapsulated Brz(Brz-NPs) and lipid shell around the core.Brz-LPNs were prepared by a modified thin-film dispersion method.With the parameters optimization of Brz-LPNs,optimal Brz-LPNs showed an average particle size of151.23±1.64 nm with a high encapsulation efficiency(EE) of 86.7%±2.28%.The core-shell structure of Brz-LPNs were confirmed by transmission electronic microscopy(TEM).Fourier transformed infrared spectra(FTIR) analysis proved that Brz was successfully entrapped into Brz-LPNs.Brz-LPNs exhibited obvious sustained release of Brz,compared with AZOPT^■ and Brz-LPs.Furthermore,the corneal accumulative permeability of Brz-LPNs significantly increased compared to the commercial available formulation(AZOPT^■) in vitro.Moreover,Brz-LPNs(1 mg/mL Brz) showed a more sustained and effective intraocular pressure(IOP) reduction than Brz-LPs(1 mg/mL) and AZOPT^■(10 mg/mL Brz) in vivo.In conclusion,Brz-LPNs,as promising ocular drug delivery systems,are well worth developing in the future for glaucoma treatment.

Semi-elastic core-shell nanoparticles enhanced the oral bioavailability of peptide drugs

The rigidity of nanoparticles was newly reported to influence their oral delivery.Semi-elastic nanoparticles can enhance the penetration in mucus and uptake by epithelial cells.However,it is still challenging and unclear that the semi-elastic core-shell nanoparticles can enhance the oral bioavailability of peptide drugs.This study was for the first time to validate the semi-elastic coreshell poly(lactic-co-glycolic acid)(PLGA)-lipid nanoparticles(LNPs)as the carrier of the oral peptide drug.The antihypertensive peptide Val-Leu-Pro-Val-Pro(VP5)loaded LNPs(VP5-LNPs)were prepared by a modified thin-film ultrasonic dispersion method.Uptake experiment was performed in Caco-2 and HT-29 cells and monito red by high content screening(HCS)and flow cyto metric(FCM).Pharmacokinetics of VP5-LNPs was carried out in Sprague-Dawley(SD)rats and analyzed by DAS 2.0.The optimal VP5-LNPs had an average particle size of 247.3±3.8 nm,zeta potential of-6.57±0.45 mV and excellent entrapment efficiency(EE)of 89.88%±1.23%.Transmission electron microscope(TEM)and Differential scanning calorimeter(DSC)further confirmed the core-shell structure.VP5-LNPs could increase the cellular uptake in vitro and have a 2.55-fold increase in AUC0-72 h,indicating a great promotion of the o ral bioavailability.The semi-elastic LNPs remarkably improved the oral availability of peptide and could be a promising oral peptide delivery system for peptide drugs in the future.