Anti-Inflammatory Therapeutic Effect of Adiponectin Gene Delivery Using a Polymeric Carrier in an Acute Lung Injury Model

Alterations in Adiponectin Expression in Models of Cigarette Smoke Extract-Induced Mouse Pulmonary Emphysema and Alveolar Epithelial Cell Injury

PURPOSE

Cigarette smoke activates lung inflammation and destruction and the development of COPD. Among various factors influenced by lung inflammation, adiponectin produced by lung epithelial cells is thought to play a significant role in regulating inflammation and maintaining tissue integrity. This study aims to examine adiponectin expression in a mouse model of cigarette smoke extract (CSE)-induced emphysema and explore the effects of adiponectin on cell survival and cytokine gene expression in CSE-induced lung epithelial cell damage.

METHODS

CSE was prepared by passing cigarette smoke through a glass tube containing solvent. PBS or CSE was intraperitoneally administered to C57BL/6 mice. Inflammatory cells, cytokines, adiponectin expression in lung, bronchoalveolar lavage fluid (BALF) and adipose tissue were assessed. CSE and adiponectin were administered to A549 cells to determine cell viability and cytokine gene expression.

RESULTS

Intraperitoneal CSE injection significantly increased the mean alveolar linear intercept by 23.11%. CSE significantly increased total cells, macrophages, neutrophils, eosinophils, TNFα, IL-1β levels in BALF. CSE enhanced lung adiponectin protein expression. Treatment of A549 cells with CSE reduced cell survival and adiponectin gene expression. Furthermore, adiponectin treatment enhanced MCP-1 and IL-8 gene expression in A549 cells post-CSE exposure.

CONCLUSION

Intraperitoneal CSE treatment induced lung inflammation, airspace enlargement, and increased adiponectin expression in mice. CSE-exposed A549 cells showed reduced cell viability, upregulated proinflammatory genes, downregulated adiponectin genes. Adiponectin treatment further intensified these genes expressions, aligning with in vivo findings. Elevated adiponectin expression in alveolar epithelial cells suggests its potential role in the development of COPD by enhancing lung inflammation.

Nanotherapy therapy for acute respiratory distress syndrome: a review

Acute respiratory distress syndrome (ARDS) is a complex and life-threatening disease characterized by severe respiratory failure. The lethality of ARDS remains alarmingly high, especially with the persistent ravages of coronavirus disease 2019 (COVID-19) in recent years. ARDS is one of the major complications of neocoronavirus pneumonia and the leading cause of death in infected patients. The large-scale outbreak of COVID-19 has greatly increased the incidence and mortality of ARDS. Despite advancements in our understanding of the causes and mechanisms of ARDS, the current clinical practice is still limited to the use of supportive medications to alleviate its progression. However, there remains a pressing need for effective therapeutic drugs to combat this devastating disease. In this comprehensive review, we discuss the commonly used therapeutic drugs for ARDS, including steroids, vitamin C, targeted inhibitors, and heparin. While these medications have shown some promise in managing ARDS, there is still a significant gap in the availability of definitive treatments. Moreover, we highlight the potential of nanocarrier delivery systems, such as liposomes, lipid nanoparticles, polymer nanoparticles, and inorganic nanoparticles, as promising therapeutic approaches for ARDS in the future. These innovative delivery systems have demonstrated encouraging results in early clinical trials and offer the potential for more targeted and effective treatment options. Despite the promising early results, further clinical trials are necessary to fully assess the efficacy and safety of nanotherapies for ARDS. Additionally, more in-depth research should be conducted to focus on the continuous development of precision therapies targeting different stages of ARDS development or different triggers. This will provide more ideas and rationale for the treatment of ARDS and ultimately lead to better patient outcomes.

Pulmonary delivery of cell membrane-derived nanovesicles carrying anti-miRNA155 oligonucleotides ameliorates LPS-induced acute lung injury

Acute lung injury (ALI) is a devastating inflammatory disease. MicroRNA155 (miR155) in alveolar macrophages and lung epithelial cells enhances inflammatory reactions by inhibiting the suppressor of cytokine signaling 1 (SOCS1) in ALI. Anti-miR155 oligonucleotide (AMO155) have been suggested as a potential therapeutic reagent for ALI. However, a safe and efficient carrier is required for delivery of AMO155 into the lungs for ALI therapy. In this study, cell membrane-derived nanovesicles (CMNVs) were produced from cell membranes of LA4 mouse lung epithelial cells and evaluated as a carrier of AMO155 into the lungs. For preparation of CMNVs, cell membranes were isolated from LA4 cells and CMNVs were produced by extrusion. Cholesterol-conjugated AMO155 (AMO155c) was loaded into CMNVs and extracellular vesicles (EVs) by sonication. The physical characterization indicated that CMNVs with AMO155c (AMO155c/CMNV) were membrane-structured vesicles with a size of ∼120 nm. The delivery efficiency and therapeutic efficacy of CMNVs were compared with those of EVs or polyethylenimine (25 kDa, PEI25k). The delivery efficiency of AMO155c by CMNVs was similar to that by EVs. As a result, the miR155 levels were reduced by AMO155c/CMNV and AMO155c/EV. AMO155c/CMNV were administered intratracheally into the ALI models. The SOCS1 levels were increased more efficiently by AMO155c/CMNV than by the others, suggesting that miR155 effectively was inhibited by AMO155c/CMNV. In addition, the inflammatory cytokines were reduced more effectively by AMO155c/CMNV than they were by AMO155c/EV and AMO155c/PEI25k, reducing inflammation reactions. The results suggest that CMNVs are a useful carrier of AMO155c in the treatment of ALI.

Antisense-oligonucleotide co-micelles with tumor targeting peptides elicit therapeutic effects by inhibiting microRNA-21 in the glioblastoma animal models

INTRODUCTION

miRNA-21 (miR-21) is highly expressed in glioblastoma, facilitating tumor growth by blocking the expression of apoptosis-related genes. Therefore, an antisense microRNA oligonucleotide (AMO) against miR-21 was suggested as a therapeutic nucleic acid for glioblastoma.

OBJECTIVES

AMO21 co-micelles were developed with tumor-targeting T7 peptides as an AMO21 delivery system by intranasal administration.

METHODS

Cholesterol-conjugated AMO21 (AMO21c) was mixed with cholesterol-conjugated T7 peptides (T7c) to produce tumor-targeted co-micelles. Physical characterization was performed by dynamic light scattering, gel retardation assay, scanning electron microscope and heparin competition assay. In vitro transfection efficiency to C6 glioblastoma cells was measured by flow cytometry. The AMO21c/T7c co-micelles were administered by intranasal instillation into the brain of intracranial glioblastoma rat models. Scrambled T7 (scrT7) and scrambled AMO21c (scrAMO21c) were used as a negative control. The therapeutic effects of the AMO21c/T7c co-micelles were evaluated by real time RT-PCR, immunohistochemistry, TUNEL assay, and Nissl staining.

RESULTS

The formation of the AMO21c/T7c co-micelles was confirmed in gel retardation and heparin competition assays. The highest delivery efficiency in vitro was achieved at a 1:10 wt ratio of AMO21c/T7c. The AMO21c/T7c co-micelles had higher delivery efficiency into C6 glioblastoma cells than naked AMO21c or AMO21c/lipofectamine complexes. After intranasal administration into the intracranial glioblastoma models, the delivery efficiency of the co-micelles into the brain was also higher than those of naked AMO21c and AMO21c/scrambled T7c. Thanks to their enhanced delivery efficiency, the AMO21c/T7c co-micelles downregulated miR-21, inducing the production of the pro-apoptotic phosphatase and tensin homolog (PTEN) and programmed cell death 4 (PDCD4) proteins in the tumor tissues. The tumor size was reduced by the AMO21c/T7c co-micelles more effectively than naked AMO21c, AMO21c/lipofectamine, or scrAMO21c/T7c treatment.

CONCLUSION

The results suggest that the co-micelles of AMO21c and T7c may be an efficient delivery system into a brain tumor through intranasal administration.

Delivery systems of therapeutic nucleic acids for the treatment of acute lung injury/acute respiratory distress syndrome

Acute lung injury (ALI)/ acute respiratory distress syndrome (ARDS) is a devastating inflammatory lung disease with a high mortality rate. ALI/ARDS is induced by various causes, including sepsis, infections, thoracic trauma, and inhalation of toxic reagents. Corona virus infection disease-19 (COVID-19) is also a major cause of ALI/ARDS. ALI/ARDS is characterized by inflammatory injury and increased vascular permeability, resulting in lung edema and hypoxemia. Currently available treatments for ALI/ARDS are limited, but do include mechanical ventilation for gas exchange and treatments supportive of reduction of severe symptoms. Anti-inflammatory drugs such as corticosteroids have been suggested, but their clinical effects are controversial with possible side-effects. Therefore, novel treatment modalities have been developed for ALI/ARDS, including therapeutic nucleic acids. Two classes of therapeutic nucleic acids are in use. The first constitutes knock-in genes for encoding therapeutic proteins such as heme oxygenase-1 (HO-1) and adiponectin (APN) at the site of disease. The other is oligonucleotides such as small interfering RNAs and antisense oligonucleotides for knock-down expression of target genes. Carriers have been developed for efficient delivery for therapeutic nucleic acids into the lungs based on the characteristics of the nucleic acids, administration routes, and targeting cells. In this review, ALI/ARDS gene therapy is discussed mainly in terms of delivery systems. The pathophysiology of ALI/ARDS, therapeutic genes, and their delivery strategies are presented for development of ALI/ARDS gene therapy. The current progress suggests that selected and appropriate delivery systems of therapeutic nucleic acids into the lungs may be useful for the treatment of ALI/ARDS.

Gene Therapy for Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is a devastating clinical syndrome that leads to acute respiratory failure and accounts for over 70,000 deaths per year in the United States alone, even prior to the COVID-19 pandemic. While its molecular details have been teased apart and its pathophysiology largely established over the past 30 years, relatively few pharmacological advances in treatment have been made based on this knowledge. Indeed, mortality remains very close to what it was 30 years ago. As an alternative to traditional pharmacological approaches, gene therapy offers a highly controlled and targeted strategy to treat the disease at the molecular level. Although there is no single gene or combination of genes responsible for ARDS, there are a number of genes that can be targeted for upregulation or downregulation that could alleviate many of the symptoms and address the underlying mechanisms of this syndrome. This review will focus on the pathophysiology of ARDS and how gene therapy has been used for prevention and treatment. Strategies for gene delivery to the lung, such as barriers encountered during gene transfer, specific classes of genes that have been targeted, and the outcomes of these approaches on ARDS pathogenesis and resolution will be discussed.

Efficient Treatment of Rheumatoid Arthritis by Degradable LPCE Nano-Conjugate-Delivered p65 siRNA

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases worldwide, causing severe cartilage damage and disability. Despite the recent progress made in RA treatment, limitations remain in achieving early and efficient therapeutic intervention. Advanced therapeutic strategies are in high demand, and siRNA-based therapeutic technology with a gene-silencing ability represents a new approach for RA treatment. In this study, we created a cationic delivery micelle consisting of low-molecular-weight (LMW) polyethylenimine (PEI)–cholesterol–polyethylene glycol (PEG) (LPCE) for small interfering RNA (siRNA)-based RA gene therapy. The carrier is based on LMW PEI and modified with cholesterol and PEG. With these two modifications, the LPCE micelle becomes multifunctional, and it efficiently delivered siRNA to macrophages with a high efficiency greater than 70%. The synthesized LPCE exhibits strong siRNA protection ability and high safety. By delivering nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65 siRNA, the p65 siRNA/LPCE complex efficiently inhibited macrophage-based cytokine release in vitro. Local administration of the p65 siRNA/LPCE complex exhibited a fast and potent anti-inflammatory effect against RA in a mouse model. According to the results of this study, the functionalized LPCE micelle that we prepared has potential gene therapeutic implications for RA.

Nanomedicine to advance the treatment of bacteria-induced acute lung injury

Bacteria-induced acute lung injury (ALI) is associated with a high mortality rate due to the lack of an effective treatment. Patients often rely on supportive care such as low tidal volume ventilation to alleviate the symptoms. Nanomedicine has recently received much attention owing to its premium benefits of delivering drugs in a sustainable and controllable manner while minimizing the potential side effects. It can effectively improve the prognosis of bacteria-induced ALI through targeted delivery of drugs, regulation of multiple inflammatory pathways, and combating antibiotic resistance. Hence, in this review, we first discuss the pathogenesis of ALI and its potential therapeutics. In particular, the state-of-the-art nanomedicines for the treatment of bacteria-induced ALI are highlighted, including their administration routes, in vivo distribution, and clearance. Furthermore, the available bacteria-induced ALI animal models are also summarized. In the end, future perspectives of nanomedicine for ALI treatment are proposed.

Nanomedicine for acute respiratory distress syndrome: The latest application, targeting strategy, and rational design

Acute respiratory distress syndrome (ARDS) is characterized by the severe inflammation and destruction of the lung air-blood barrier, leading to irreversible and substantial respiratory function damage. Patients with coronavirus disease 2019 (COVID-19) have been encountered with a high risk of ARDS, underscoring the urgency for exploiting effective therapy. However, proper medications for ARDS are still lacking due to poor pharmacokinetics, non-specific side effects, inability to surmount pulmonary barrier, and inadequate management of heterogeneity. The increased lung permeability in the pathological environment of ARDS may contribute to nanoparticle-mediated passive targeting delivery. Nanomedicine has demonstrated unique advantages in solving the dilemma of ARDS drug therapy, which can address the shortcomings and limitations of traditional anti-inflammatory or antioxidant drug treatment. Through passive, active, or physicochemical targeting, nanocarriers can interact with lung epithelium/endothelium and inflammatory cells to reverse abnormal changes and restore homeostasis of the pulmonary environment, thereby showing good therapeutic activity and reduced toxicity. This article reviews the latest applications of nanomedicine in pre-clinical ARDS therapy, highlights the strategies for targeted treatment of lung inflammation, presents the innovative drug delivery systems, and provides inspiration for strengthening the therapeutic effect of nanomedicine-based treatment.

Delivery of MiRNA-92a Inhibitor Using RP1-Linked Peptide Elicits Anti-Inflammatory Effects in an Acute Lung Injury Model

Acute lung injury (ALI) is an inflammatory lung disease. miRNA-92a (miR92a) is induced in the lungs of ALI patients and mediates inflammatory reactions. In this study, a RP1-linked R3V6 (RP1R3V6) peptide was synthesized and evaluated as a carrier of anti-microRNA-92a oligonucleotide (AMO92a) into the lungs of an ALI animal model. In addition to the carrier function, the RP1-linked peptide can have anti-inflammatory effects in the lungs, since RP1 is an antagonist of the receptors for advanced glycation end-products (RAGEs). In a gel retardation assay, the RP1R3V6 peptide formed a spherical complex with AMO92a. In an in vitro delivery assay to L2 rat lung epithelial cells, RP1R3V6 had a lower AMO92a delivery efficiency than R3V6 and polyethyleneimine (PEI25k; 25 kDa). However, RP1R3V6 had an additional anti-inflammatory effect, reducing tumor necrosis factor-α (TNF-α) in lipopolysaccharide-activatedmacrophage cells. With the combined effects of AMO92a and RP1, the RP1R3V6/AMO92a complex reduced the miR92a level more efficiently than did the R3V6/AMO92a and PEI25k/AMO92a complexes. The RP1R3V6/AMO92a complex was administered into the lungs of ALI animals by intratracheal instillation. As a result, the expression of phosphatase and tensin homolog, a target of miR92a, was increased in the lungs. Furthermore, the RP1R3V6/AMO92a complex decreased the TNF-α and interleukin-1β (IL-1β) levels more efficiently than did the PEI25k/AMO92a and R3V6/AMO92a complexes, decreasing the damage in the lungs. These results suggest that RP1R3V6 is a useful carrier of AMO92a and has anti-inflammatory effects in an ALI animal model.

Natural steroid-based cationic copolymers cholesterol/diosgenin-r-PDMAEMAs and their pDNA nanoplexes: impact of steroid structures and hydrophobic/hydrophilic ratios on pDNA delivery

Using natural-based lipids to construct biocompatible, controllable and efficient nanocarriers and elucidating their structure-function relationships, was regarded as an important area for creating sustainable biomaterials. Herein, we utilized two natural steroids: cholesterol and diosgenin (bearing different hydrophobic tails) as the building blocks, to synthesize a series of natural steroid-based cationic random copolymers PMA6Chol-r-PDMAEMA and PMA6Dios-r-PDMAEMA via RAFT polymerization. The results demonstrated that the steroid-r-PDMAEMA copolymers could efficiently bind pDNA (N/P < 3.0) and then form near-spherical shape (142-449 nm) and positively-charged (+11.5 to +19.6 mV) nanoparticles. The in vitro cytotoxicity and gene transfection efficiency greatly depend on the steroid hydrophobic tail structures and steroid/PDMAEMA block ratios. Optimum transfection efficiency of the (Chol-P1/pDNA and Dios-P3/pDNA) nanoplexes could reach to 18.1-31.2% of the PEI-25K/pDNA complex. Moreover, all of the steroid-r-PDMAEMA/Cy3-pDNA nanoplexes have an obvious "lysosome localization" effect, indicating the steroid structures do not remarkably influence the intracellular localization behaviors of these nanoplexes.

Nanomedicine-Based Therapeutics to Combat Acute Lung Injury

Acute lung injury (ALI) or its aggravated stage acute respiratory distress syndrome (ARDS) may lead to a life-threatening form of respiratory failure, resulting in high mortality of up to 30-40% in most studies. Although there have been decades of research since ALI was first described in 1967, the clinical therapeutic alternatives for ALI are still in a state of limited availability. Supportive treatment and mechanical ventilation still have priority. Despite some preclinical studies demonstrating the benefit of pharmacological interventions, none of these has been proved completely effective to date. Recent advances in nanotechnology may shed new light on the pharmacotherapy of ALI. Nanomedicine possesses targeting and synergistic therapeutic capability, thus boosting pharmaceutical efficacy and mitigating the side effects. Currently, a variety of nanomedicine with diverse frameworks and functional groups have been elaborately developed, in accordance with their lung targeting ability and the pathophysiology of ALI. The in-depth review of the current literature reveals that liposomes, polymers, inorganic materials, cell membranes, platelets, and other nanomedicine approaches have conferred attractive therapeutic benefits for ALI treatment. In this review, we explore the recent progress in the study of the nanomedicine-based therapy of ALI, presenting various nanomedical approaches, drug choices, therapeutic strategies, and outcomes, thereby providing insight into the trends.

Antioxidant/Anti-Inflammatory Effects of Caloric Restriction in an Aged and Obese Rat Model: The Role of Adiponectin

Caloric restriction (CR) represents a powerful intervention for extending healthspan and lifespan in several animal models, from yeast to primates. Additionally, in humans, CR has been found to induce cardiometabolic adaptations associated with improved health. In this study, we evaluated in an aged and obese rat model the effect of long-term (6 months) caloric restriction (−40%) on the oxidative/inflammatory balance in order to investigate the underlining mechanisms. In plasma, we analyzed the oxidative balance by photometric tests and the adiponectin/tumor necrosis factor-α-induced gene/protein 6 (TSG-6) levels by Western blot analysis. In the white adipose tissue, we examined the protein levels of AdipoR1, pAMPK, NFκB, NRF-2, and glutathione S-tranferase P1 by Western blot analysis. Our results clearly showed that caloric restriction significantly improves the plasmatic oxidative/inflammatory balance in parallel with a major increase in circulating adiponectin levels. Additionally, at the level of adipose tissue, we found a positive modulation of both anti-inflammatory and antioxidant pathways. These adaptations, induced by caloric restriction, with the achievement of normal weight, suggest that inflammatory and redox imbalance in obese aged rats appear to be more linked to obesity than to aging.

Brain gene delivery using histidine and arginine-modified dendrimers for ischemic stroke therapy

Polyamidoamine dendrimer has been studied as an efficient gene carrier. Due to its anti-inflammatory properties, polyamidoamine is a useful gene carrier, especially for inflammatory diseases. However, the commonly used polyamidoamine generation 6 dendrimer (PG6) has higher cytotoxicity than low-molecular weight polyamidoamines, which limits its applications. Therefore, early-generation polyamidoamine dendrimers, such as generation 2 (PG2), have been investigated as an alternative to PG6, although PG2 has a lower transfection efficiency. In this study, to improve gene delivery efficiency, histidine and arginine were conjugated on the primary amines of PG2, synthesizing PG2HR. The gene delivery efficiency of PG2HR was higher than that of PG2 or of PG2 conjugated with only arginine (PG2R), which may be due to higher cellular uptake and endosomal escape of the plasmid DNA (pDNA)/PG2HR complex. In addition, PG2HR had lower cytotoxicity than polyethylenimine (25 kDa, PEI25k), PG2, and PG2R. Mechanism studies showed that PG2HR delivered pDNA into the cells mainly by clathrin-independent endocytosis and partly by macropinocytosis. The therapeutic potential of PG2HR-mediated gene delivery was evaluated in middle cerebral artery occlusion (MCAO)-reperfusion stroke animal models. Heme oxygenase-1 (HO-1) plasmid was delivered into the brain by local injection. The results showed that PG2HR had higher gene delivery efficiency in the brain than did PEI25k, PG2, or PG2R. Furthermore, compared to the pHO-1/PEI25k, pHO-1/PG2, and pHO-1/PG2R complexes, the pHO-1/PG2HR complex had reduced apoptosis levels and infarct sizes in ischemic brains. Therefore, because of its low cytotoxicity and high gene delivery efficiency, PG2HR may be useful for gene therapy of inflammatory diseases including ischemic stroke.

A RAGE-antagonist peptide potentiates polymeric micelle-mediated intracellular delivery of plasmid DNA for acute lung injury gene therapy

Acute lung injury (ALI) is a severe inflammatory lung disease. A high mobility group box-1 (HMGB-1) derived RAGE-antagonist peptide (RAP) was previously developed for anti-inflammatory therapy for ALI. Due to its specific binding to RAGE on the surface of inflammatory cells, the RAP may facilitate polymer-mediated intracellular delivery of plasmid DNA (pDNA) into the inflammatory cells. To evaluate this hypothesis, a pDNA/polymer/RAP ternary-complex was produced and applied for ALI gene therapy. Dexamethasone-conjugated polyamidoamine G2 (PAM-D) was used as a gene carrier, and the adiponectin (APN) gene was employed as a therapeutic gene. First, the ratio of pDNA to PAM-D was optimized in terms of anti-inflammation and low toxicity. Then, the RAP was added to the pDNA/PAM-D complex, producing the pDNA/PAM-D/RAP complex. The transfection efficiency of the luciferase plasmid (pLuc)/PAM-D/RAP reached its maximum at a weight ratio of 1 : 2 : 9. At this weight ratio, pLuc/PAM-D/RAP had a higher transfection efficiency than pLuc/PAM-D or pLuc/RAP. The transfection efficiency of pLuc/PAM-D/RAP decreased due to competition with free RAPs, suggesting the RAGE-mediated endocytosis of the complex. In the LPS-activated ALI mouse models, intratracheal administration of APN plasmid (pAPN)/PAM-D/RAP induced higher APN expression and less pro-inflammatory cytokines in the lungs of ALI animal models than pAPN/PEI25k, pAPN/RAP, and pAPN/PAM-D. Hematoxylin and eosin staining confirmed the higher anti-inflammatory effect of pAPN/PAM-D/RAP than the other complexes in the ALI models. Therefore, RAP-mediated enhanced delivery of pAPN/PAM-D may be useful for the development of a treatment for ALI.

Inhalable Gene Delivery System Using a Cationic RAGE-Antagonist Peptide for Gene Delivery to Inflammatory Lung Cells

Acute lung injury (ALI) is a severe lung inflammatory disease. In ALI, the receptor for advanced glycation end-products (RAGE) is overexpressed in lung epithelial cells and involved in inflammatory reactions. A previous report showed that a RAGE-antagonist peptide (RAP), from high-mobility group box-1, bound to RAGE and reduced inflammatory reactions. RAP has high levels of positive amino acids, which suggests that RAP may form a complex with plasmid DNA (pDNA) by charge interactions. Because the charge density of RAP is lower than polyethylenimine (25 kDa, PEI25k), it may be able to avoid capture by the negatively charged mucus layer more easily and deliver pDNA into RAGE-positive lung cells of ALI animals by RAGE-mediated endocytosis. To prove this hypothesis, RAP was evaluated as a delivery carrier of adiponectin plasmid (pAPN) in lipopolysaccharide (LPS)-induced ALI animal models. In vitro transfection assays showed that RAP had lower transfection efficiency than PEI25k in L2 lung epithelial cells. However, in vivo administration to ALI animal models by inhalation showed that RAP had higher gene delivery efficiency than PEI25k. Particularly, due to a higher expression of RAGE in lung cells of ALI animals, the gene delivery efficiency of RAP was higher in ALI animals than that in normal animals. Delivery of the pAPN/RAP complex had anti-inflammatory effects, reducing pro-inflammatory cytokines. Hematoxylin and eosin staining confirmed that pAPN/RAP decreased inflammation in ALI models. Therefore, the results suggest that RAP may be useful as a carrier of pDNA into the lungs for ALI gene therapy.

Combined delivery of curcumin and the heme oxygenase-1 gene using cholesterol-conjugated polyamidoamine for anti-inflammatory therapy in acute lung injury

BACKGROUND

Acute lung injury (ALI) is an inflammatory lung disease with a high mortality rate. In this study, combined delivery of the anti-inflammatory compound curcumin and the heme-oxygenase-1 (HO-1) gene using cholesterol-conjugated polyamidoamine was evaluated in a mouse model as a therapeutic option for ALI.

METHODS

Curcumin was loaded into cholesterol-conjugated polyamidoamine (PamChol) micelles, and curcumin-loaded PamChol (PamChol-Cur) was then complexed with plasmid DNA (pDNA) through charge interactions. The pDNA/PamChol-Cur complex was physically characterized by dynamic light scattering, gel retardation, and heparin competition assay. Gene delivery efficiency was measured by luciferase assay. The HO-1 expression plasmid (pHO-1)/PamChol-Cur complex was administrated into the ALI model via intratracheal injection. The anti-inflammatory effect of the pDNA/PamChol-Cur complex was evaluated by ELISA, immunohistochemistry, and hematoxylin and eosin staining.

RESULTS

The pDNA/PamChol-Cur complex had a size of approximately 120 nm with a positive surface charge. The in vitro plasmid DNA (pDNA) delivery efficiency of the pDNA/PamChol-Cur complex into L2 lung epithelial cells was higher than that of pDNA/PamChol. In addition, the curcumin in the pDNA/PamChol-Cur complex inhibited the nuclear translocation of NF-κB, suggesting an anti-inflammatory effect of curcumin. In the ALI animal model, the pHO-1/PamChol-Cur complex delivered the pHO-1 gene more efficiently than pHO-1/PamChol. In addition, the pHO-1/PamChol-Cur complex showed greater anti-inflammatory effects by reducing anti-inflammatory cytokine levels more than delivery of pHO-1/PamChol or PamChol-Cur only.

CONCLUSION

The pHO-1/PamChol-Cur complex had a higher pHO-1 gene-delivery efficiency and greater anti-inflammatory effects than the pHO-1/PamChol complex or PamChol-Cur. Therefore, the combined delivery of curcumin and pHO-1 using PamChol-Cur may be useful for treatment of ALI.

Self-assembled polymeric micelles for combined delivery of anti-inflammatory gene and drug to the lungs by inhalation

Acute lung injury (ALI) is a lung inflammatory disease for which pulmonary delivery of drug and gene could be a useful strategy. In this study, cholesterol-conjugated polyamidoamine (PAM-Chol) was synthesized and characterized as a carrier for combined delivery of anti-inflammatory gene and drug into the lungs by inhalation. The PAM-Chol formed self-assembled micelles in an aqueous solution with a critical micelle concentration of 0.22 mg ml-1. An in vitro transfection assay to L2 lung epithelial cells showed that the PAM-Chol micelle had higher transfection efficiency than lipofectamine and polyethylenimine (25 kDa, PEI25k). As the anti-inflammatory drug, resveratrol was loaded into the cores of the PAM-Chol micelles using the oil-in-water emulsion/solvent evaporation method. In lipopolysaccharide (LPS)-activated macrophage cells, resveratrol-loaded PAM-Chol (PAM-Chol/Res) reduced pro-inflammatory cytokines, confirming the anti-inflammatory effects of resveratrol. In in vitro transfection assays to L2 cells, the PAM-Chol/Res micelles had transfection efficiency similar to that of PAM-Chol. The delivery of resveratrol or the heme oxygenase-1 gene (pHO-1) by inhalation was evaluated in an ALI animal model. Resveratrol delivery using the PAM-Chol/Res micelles inhibited the nuclear translocation of nuclear factor-κB (NF-κB) and reduced pro-inflammatory cytokines in the lungs. pHO-1 delivery using PAM-Chol induced HO-1 expression and reduced pro-inflammatory cytokines. However, the highest anti-inflammatory effects were obtained with combined delivery of pHO-1 and resveratrol using the pHO-1/PAM-Chol/Res complex, as demonstrated in cytokine assays and immunohistochemical studies. Therefore, the PAM-Chol micelle is an efficient carrier of resveratrol and pHO-1 into the lungs and could be useful for the treatment of ALI by inhalation.