Interferon Regulatory Factor 5 siRNA-Loaded Folate-Modified Cationic Liposomes for Acute Lung Injury Therapy.

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is an overwhelming pulmonary inflammation with limited clinical treatment strategies. Interferon regulatory factor 5 (IRF5) is a crucial regulator of inflammation factors, which can be upregulated under an inflammatory state and related to the efferocytosis of macrophages. Herein, IRF5 was knockdown by small interfering RNA (siIRF5) to promote the anti-inflammatory effect of macrophages. Macrophage-targeting cationic liposome modified by folate (FA-LP) was developed to deliver siIRF5 (FA-LP/siIRF5). Liposomes were characterized for their particle size, zeta potential, protein adsorption and hemolysis of red blood cells. The amount of IRF5 mRNA and the expression of IRF5 were measured using quantitative reverse transcription PCR (RT-qPCR) and western blot, respectively. The phenotype and efferocytosis of macrophages and the regulatory pathway of efferocytosis and biodistribution of liposomes in the ALI mice model were investigated. Data revealed that FA-LP/siIRF5 could obviously downregulate the expression of IRF5 in macrophages, skewing the polarization of macrophages to M2 phenotype (anti-inflammatory state) and thus improving their efferocytosis. Moreover, regulation of efferocytosis of macrophages by siIRF5 is related to the NF- B pathway. The in vivo biodistribution of FA-LP exhibited higher accumulation in the inflammatory lungs, suggesting that FA-LP could be considered as a promising gene delivery system and FA-LP/siIRF5 is an alternative strategy for the treatment of ALI/ARDS. To the best of our knowledge, this is the first study reporting that siIRF5 can be used for the treatment of ALI/ARDS.

Investigating the Fate of MP1000-LPX In Vivo by Adding Serum to Transfection Medium.

BACKGROUND: Cationic liposomes (CLs) based messenger RNA (mRNA) vaccine has been a promising approach for cancer treatment. However, rapid lung accumulation after intraveous injection and significantly decreased transfection efficacy (TE) in serum substantially hamper its application. OBJECTIVE: In this study, we attempt to investigate the fate of Mannose-PEG1000-lipoplex (MP1000-LPX) in vivo, a previous reported mRNA vaccine, and potential mechanism in it. METHODS: MP1000-CLs and different type of MP1000-LPX were produced by previous method and characterized by dynamic light scattering (DLS). Organ distribution and Luc-mRNA expression of DiD loaded luciferase (Luc-mRNA)-MP1000-LPX were evaluated by IVIS Spectrum imaging system. Cellular transfection and uptake under serum-free and serum-containing conditions were analysed by flow cytometry and counted by FlowJo software. RESULTS: MP1000-CLs had an average size of 45.3 ± 0.9 nm, a positive charge of 39.9 ± 0.9 mV. When MP1000-LPX formed, the particle size increased to about 130 nm, and zeta potential decreased to about 30 mV. All formulations were in narrow size distribution with PDI < 0.3. 6 h after intraveous injection, Luc-MP1000-LPX mostly distributed to liver, lung and spleen, while only successfully expressed Luc in lung. DC2.4 cellular transfection assay indicated serum substantially lowered TE of MP1000-LPX. However, the cellular uptake on DC2.4 cells was enhanced in the presence of serum. CONCLUSION: MP1000-LPX distributed to spleen but failed to transfect. Because serum dramatically decreased TE of MP1000-LPX on DC2.4 cells, but not by impeding its interaction to cell membrane. Serum resistance and avoidance of lung accumulation might be prerequisites for CLs based intravenous mRNA vaccines. Lay Summary: mRNA vaccine has been promising immunotherapy to treat cancer by delivering mRNA encoding tumor antigens to APCs and activating immune system against tumor cells. We are investigating the in vivo fate of MP1000-LPX, a CLs based mRNA vaccine. To see if serum causes the fate, we'll be looking at the influence of serum on transfection and uptake efficacy of MP1000-LPX by DC2.4 cells experiments in vitro. Our findings will imply that serum inhibits transfection but not by decreasing uptake. Thus, we can ultilize serum to enhance transfection if we make intracellular process of MP1000-LPX successful.

A Tenofovir-Loaded Glycyrrhetinic Acid-Modified Cationic Liposome for Targeted Therapy of Hepatitis B Virus.

Tenofovir (TFV), an acyclic nucleoside analog, exhibits potent anti-HBV activity. However, poor bioavailability, nephrotoxicity and bone toxicity limit its further clinical application. In this work, a novel tenofovir-loaded glycyrrhetinic acidmodified cationic liposome (TGCL) was prepared for targeted therapy of HBV. The TGCL had an average particle size of 107.39 ± 1.21 nm and an entrapment efficiency of 89.83 ± 2.70% with a positive zeta potential of 37.63 ± 1.22 mV. The results of in vitro indicated that the inhibitory effects on HBsAg, HBeAg and HBV cccDNA of TGCL in HepG2.2.15 cells were significantly better than that of free TFV and non-targeted cationic liposome. In the DHBV-infected duck model, TGCL showed remarkably suppression on DHBV DNA than that of free TFV. Overall, TGCL is a promising formulation of TFV for targeted therapy of HBV.