The use of nanoparticles to deliver nitric oxide to hepatic stellate cells for treating liver fibrosis and portal hypertension

Simvastatin-loaded polymeric micelles are more effective and less toxic than conventional statins in a pre-clinical model of advanced chronic liver disease

Chronic liver disease (CLD) has no effective treatments apart from reducing its complications. Simvastatin has been tested as vasoprotective drug in experimental models of CLD showing promising results, but also limiting adverse effects. Two types of Pluronic® carriers loading simvastatin (PM108-simv and PM127-simv) as a drug delivery system were developed to avoid these toxicities while increasing the therapeutic window of simvastatin. PM127-simv showed the highest rates of cell internalization in rat liver sinusoidal endothelial cells (LSECs) and significantly lower toxicity than free simvastatin, improving cell phenotype. The in vivo biodistribution was mainly hepatic with 50% of the injected PM found in the liver. Remarkably, after one week of administration in a model of CLD, PM127-simv demonstrated superior effect than free simvastatin in reducing portal hypertension. Moreover, no signs of toxicity of PM127-simv were detected. Our results indicate that simvastatin targeted delivery to LSEC is a promising therapeutic approach for CLD.

Innovative Nanotechnological Formulations to Reach the Hepatic Stellate Cell

Purpose of Review

Treatment of liver fibrosis benefits from hepatic stellate cell (HSC)-specific delivery. Since the description of first carrier to HSC, many developments have taken place in this area. The purpose is to give an overview of the different carriers and homing moieties that are available for HSC targeting and illustrate the opportunities and hurdles they provide.

Recent Findings

There is a growing number of homing devices to deliver drugs to HSC, and options to deliver siRNA to HSC have emerged. Other developments include controlling corona formation, development of linker technology, and design of theranostic approaches. We are on the eve of reaching the clinic with innovative HSC-specific compounds.

Summary

An overview of different core molecules is presented together with an overview of targeting strategies toward different receptors on HSC, providing a versatile toolbox. Many therapeutics, ranging from small chemical entities and proteins to RNA- or DNA-modulating substances, have already been incorporated in these constructs in the recent years.

Hyperbranched lipoid-based lipid nanoparticles for bidirectional regulation of collagen accumulation in liver fibrosis

Liver fibrosis leads to over one million deaths annually worldwide. Hepatic stellate cells (HSCs) have been identified as the main executors of liver fibrosis. Unfortunately, no drug has yet been approved for clinical use against liver fibrosis, largely because the tested drugs have been unable to access HSCs and efficiently remove the collagen accumulation involved in fibrogenesis. Here, we designed an efficient HSC-targeting lipid delivery system that carried dual siRNAs intended to both inhibit collagen synthesis and promote collagen degradation, with the goal of realizing enhanced anti-liver fibrosis by bidirectional regulation of collagen accumulation. The delivery system was constructed by using amphiphilic cationic hyperbranched lipoids (C₁₅-PA) for siRNA complexation and helper lipoids (cholesterol-polyethylene glycol-vitamin A, Chol-PEG-VA) for HSCs targeting. The generated vitamin A-decorated and hyperbranched lipoid-based lipid nanoparticles (VLNPs) showed excellent gene-binding ability and transfection efficiency, and enhanced the delivery of siRNAs to HSCs. Fibrotic mice treated with dual siRNA-loaded VLNPs showed a great reduction in the collagen accumulation seen in this model; the enhanced effect of bidirectional regulation reduced the collagen accumulation level in treated mice to almost that seen in normal mice. There was no notable sign of toxicity or tissue inflammation in mice exposed to repeated intravenous administration of the dual siRNA-loaded VLNPs. In conclusion, our results indicate that biocompatible VLNPs designed to exploit precise targeting and an effective bidirectional regulation strategy hold promise for treating liver fibrosis.

α2-Adrenergic Receptor in Liver Fibrosis: Implications for the Adrenoblocker Mesedin

The noradrenergic system is proposed to play a prominent role in the pathogenesis of liver fibrosis. While α1- and β-adrenergic receptors (ARs) are suggested to be involved in a multitude of profibrogenic actions, little is known about α2-AR-mediated effects and their expression pattern during liver fibrosis and cirrhosis. We explored the expression of α2-AR in two models of experimental liver fibrosis. We further evaluated the capacity of the α2-AR blocker mesedin to deactivate hepatic stellate cells (HSCs) and to increase the permeability of human liver sinusoidal endothelial cells (hLSECs). The mRNA of α2a-, α2b-, and α2c-AR subtypes was uniformly upregulated in carbon tetrachloride-treated mice vs the controls, while in bile duct-ligated mice, only α2b-AR increased in response to liver injury. In murine HSCs, mesedin led to a decrease in α-smooth muscle actin, transforming growth factor-β and α2a-AR expression, which was indicated by RT-qPCR, immunocytochemistry, and Western blot analyses. In a hLSEC line, an increased expression of endothelial nitric oxide synthase was detected along with downregulated transforming growth factor-β. In conclusion, we suggest that the α2-AR blockade alleviates the activation of HSCs and may increase the permeability of liver sinusoids during liver injury.

Antifibrotic Effects of Amyloid-Beta and Its Loss in Cirrhotic Liver

The function and regulation of amyloid-beta (Aβ) in healthy and diseased liver remains unexplored. Because Aβ reduces the integrity of the blood-brain barrier we have examined its potential role in regulating the sinusoidal permeability of normal and cirrhotic liver. Aβ and key proteins that generate (beta-secretase 1 and presenilin-1) and degrade it (neprilysin and myelin basic protein) were decreased in human cirrhotic liver. In culture, activated hepatic stellate cells (HSC) internalized Aβ more efficiently than astrocytes and HSC degraded Aβ leading to suppressed expression of α-smooth muscle actin (α-SMA), collagen 1 and transforming growth factor β (TGFβ). Aβ also upregulated sinusoidal permeability marker endothelial NO synthase (eNOS) and decreased TGFβ in cultured human liver sinusoidal endothelial cells (hLSEC). Liver Aβ levels also correlate with the expression of eNOS in transgenic Alzheimer’s disease mice and in human and rodent cirrhosis/fibrosis. These findings suggest a previously unexplored role of Aβ in the maintenance of liver sinusoidal permeability and in protection against cirrhosis/fibrosis via attenuation of HSC activation.

Application of the Nano-Drug Delivery System in Treatment of Cardiovascular Diseases

Cardiovascular diseases (CVDs) have become a serious threat to human life and health. Though many drugs acting via different mechanism of action are available in the market as conventional formulations for the treatment of CVDs, they are still far from satisfactory due to poor water solubility, low biological efficacy, non-targeting, and drug resistance. Nano-drug delivery systems (NDDSs) provide a new drug delivery method for the treatment of CVDs with the development of nanotechnology, demonstrating great advantages in solving the above problems. Nevertheless, there are some problems about NDDSs need to be addressed, such as cytotoxicity. In this review, the types and targeting strategies of NDDSs were summarized, and the new research progress in the diagnosis and therapy of CVDs in recent years was reviewed. Future prospective for nano-carriers in drug delivery for CVDs includes gene therapy, in order to provide more ideas for the improvement of cardiovascular drugs. In addition, its safety was also discussed in the review.

Extracellular matrix-penetrating nanodrill micelles for liver fibrosis therapy

As hepatic stellate cells (HSCs) are essential for hepatic fibrogenesis, HSCs targeted nano-drug delivery system is a research hotspot in liver fibrosis therapy. However, the excessive deposition of fibrosis collagen (mainly collagen I) in the space of Disse associated with hepatic fibrogenesis would significantly hinder nano-formulation delivery to HSCs. Here, we have prepared a collagenase I and retinol co-decorated polymeric micelle that possess nanodrill-like and HSCs-target function based on poly-(lactic-co-glycolic)-b-poly (ethylene glycol)-maleimide (PLGA-PEG-Mal) (named CRM) for liver fibrosis therapy. Upon encountering collagen I barrier, CRM exerted a nanodrill-like function, efficiently degrading pericellular collagen I and showing greater uptake by human HSCs than other micelle formulations. Besides, CRM could realize excellent accumulation in the fibrotic liver and accurate targeting to activated HSCs in mouse hepatic fibrosis model. Moreover, CRM loaded with nilotinib (CRM/NIL), a second-generation tyrosine kinase inhibitor used in the treatment of liver fibrosis, showed optimal antifibrotic activity. This work suggests that CRM with dual function is an efficient carrier for liver fibrosis drug delivery and collagenase I decorating could be a new strategy for building more efficient HSCs targeted nano-drug delivery system.

In Vivo Retargeting of Poly(beta aminoester) (OM-PBAE) Nanoparticles is Influenced by Protein Corona

One of the main bottlenecks in the translation of nanomedicines from research to clinics is the difficulty in designing nanoparticles actively vectorized to the target tissue, a key parameter to ensure efficacy and safety. In this group, a library of poly(beta aminoester) polymers is developed, and it is demonstrated that adding specific combinations of terminal oligopeptides (OM-PBAE), in vitro transfection is cell selective. The current study aims to actively direct the nanoparticles to the liver by the addition of a targeting molecule. To achieve this objective, retinol, successfully attached to OM-PBAE, is selected as hepatic targeting moiety. It is demonstrated that organ biodistribution is tailored, achieving the desired liver accumulation. Regarding cell type transfection, antigen presenting cells in the liver are those showing the highest transfection. Thanks to proteomics studies, organ but not cellular biodistribution can be explained by the formation of differential protein coronas. Therefore, organ biodistribution is governed by differential protein corona formed when retinol is present, while cellular biodistribution is controlled by the end oligopeptides type. In summary, this work is a proof of concept that demonstrates the versatility of these OM-PBAE nanoparticles, in terms of the modification of the biodistribution of OM-PBAE nanoparticles adding active targeting moieties.

Hepatic Cellular Distribution of Silica Nanoparticles by Surface Energy Modification

The cellular distribution of silica nanoparticles (NPs) in the liver is not well understood. Targeting specific cells is one of the most important issues in NP-based drug delivery to improve delivery efficacy. In this context, the present study analyzed the relative cellular distribution pattern of silica NPs in the liver, and the effect of surface energy modification on NPs. Hydrophobic NP surface modification enhanced NP delivery to the liver and liver sinusoid fFendothelial cells (LSECs). Conversely, hydrophilic NP surface modification was commensurate with targeting hepatic stellate cells (HSCs) rather than other cell types. There was no notable difference in NP delivery to Kupffer cells or hepatocytes, regardless of hydrophilic or hydrophobic NP surface modification, suggesting that both the targeting of hepatocytes and evasion of phagocytosis by Kupffer cells are not associated with surface energy modification of silica NPs. This study provides useful information to target specific cell types using silica NPs, as well as to understand the relationship between NP surface energy and the NP distribution pattern in the liver, thereby helping to establish strategies for cell targeting using various NPs.

Enhancing Microcirculation on Multitriggering Manner Facilitates Angiogenesis and Collagen Deposition on Wound Healing by Photoreleased NO from Hemin-Derivatized Colloids

A deficiency of nitric oxide (NO) supply has been found to impair wound healing. The exogenous topical delivery of NO is a promising approach to enhance vasodilation and stimulate angiogenesis and collagen deposition. In this study, the CN groups on the surface of Prussian blue (PB) nanocubes were carefully reduced to -CH₂-NH₂ to conjugate with COOH group of hemin consisting of a Fe-porphyrin structure with strong affinity toward NO. Accordingly, the NO gas was able to coordinate to hemin-modified PB nanocubes. The hemin-modified PB carrying NO (PB-NO) can be responsible to near-infrared (NIR) light (808 nm) exposure to induce the thermo-induced liberation of NO based on the light-to-heat transformation property of PB nanocubes. The NO supply on the incisional wound sites can be readily topically dropped the colloidal solution of PB-NO for receiving NIR light irradiation. The enhanced blood flow was in a controllable manner whenever the wound sites containing PB-NO received NIR light irradiation. The promotion of blood perfusion following the on-demand multidelivery of NO has effectively facilitated the process of wound closure to enhance angiogensis and collagen deposition.

Targeted Drug Delivery to Hepatic Stellate Cells for the Treatment of Liver Fibrosis

Liver fibrosis is caused by excessive accumulation of extracellular matrix during chronic liver injuries. Although clinical evidence suggests that liver fibrosis can be reversed, there is no standard therapy for liver fibrosis. Moreover, there is a lack of diagnostic tools to detect early-stage liver fibrosis. Activation of hepatic stellate cells (HSCs) is the key step during liver fibrogenesis, and its mechanism has been extensively studied by various cell culture and animal models. Targeted delivery of therapeutic agents to activated HSCs is therefore critical for the successful treatment of liver fibrosis. A number of protein markers have been found to be overexpressed in activated HSCs, and their ligands have been used to specifically deliver various antifibrotic agents. In this review, we summarize these HSC-specific protein markers and their ligands for targeted delivery of antifibrotic agents.

Synergistic MicroRNA Therapy in Liver Fibrotic Rat Using MRI-Visible Nanocarrier Targeting Hepatic Stellate Cells

Liver fibrosis, as one of the leading causes of liver-related morbidity and mortality, has no Food and Drug Administration (FDA)-approved antifibrotic therapy yet. Although microRNA-29b (miRNA-29b) and microRNA-122 (miRNA-122) have great potential in treating liver fibrosis via regulating profibrotic genes in hepatic stellate cells (HSCs), it is still a challenge to achieve a HSC-targeted and meanwhile noninvasively trackable delivery of miRNAs in vivo. Herein, a pH-sensitive and vitamin A (VA)-conjugated copolymer VA-polyethylene glycol-polyethyleneimine-poly(N-(N',N'-diisopropylaminoethyl)-co-benzylamino) aspartamide (T-PBP) is synthesized and assembled into superparamagnetic iron oxide (SPIO)-decorated cationic micelle for miRNA delivery. The T-PBP micelle efficiently transports the miRNA-29b and miRNA-122 to HSC in a magnetic resonance imaging-visible manner, resulting in a synergistic antifibrosis effect via downregulating the expression of fibrosis-related genes, including collagen type I alpha 1, α-smooth muscle actin, and tissue inhibitor of metalloproteinase 1. Consequently, the HSC-targeted combination therapy with miRNA-29b and miRNA-122 demonstrates a prominent antifibrotic efficacy in terms of improving liver function and relieving hepatic fibrosis.

Nano-carriers for drug routeing - towards a new era

The objective of this article is to propose a re-visiting of the paradigms of nano-carriers based drug routeing from an industrial viewpoint. The accumulation of drugs in specific body compartments after intravenous administration and the improvement of the oral bioavailability of peptides were taken as examples to propose an update of the translational framework preceding industrialisation. In addition to the recent advances on the biopharmacy of nano-carriers, the evolution of adjacent disciplines such as the biology of diseases, the chemistry of polymers, lipids and conjugates, the physico-chemistry of colloids and the assembling of materials at the nanoscale (referred to as microfluidics) are taken into account to consider new avenues in the applications of drug nano-carriers. The deeper integration of the properties of the drug and of the nano-carrier, in the specific context of the disease, advocates for product oriented programmes. At the same time, the advent of powerful collaborative digital tools makes possible the extension of the expertise spectrum. In this open-innovation framework, the Technology Readiness Levels (TRLs) of nano-carriers are proposed as a roadmap for the translational process from the Research stage to the Proof-of-Concept in human.

Nanoparticle mediated silencing of tenascin C in hepatic stellate cells: effect on inflammatory gene expression and cell migration

Mesoporous silica nanoparticles efficiently knock-down tenascin-C in hepatic stellate cells resulting in decrease of inflammatory cytokine levels and hepatocyte migration.

Unraveling Polymeric Nanoparticles Cell Uptake Pathways: Two Decades Working to Understand Nanoparticles Journey to Improve Gene Therapy

Polymeric nanoparticles have aroused an increasing interest in the last decades as novel advanced delivery systems to improve the treatment of many diseases. Hard work has been performed worldwide designing and developing polymeric nanoparticles using different building blocks, which target specific cell types, trying to avoid bioaccumulation and degradation pathways. The main handicap of the design is to understand the final fate and the journey that the nanoparticle will follow, which is intimately ligated with the chemical and physical properties of the nanoparticles themselves and specific factors of the targeted cells. Although the huge number of published scientific articles regarding polymeric nanoparticles for biomedical applications, their use in clinics is still limited. This fact could be explained by the limited data reporting the interaction of the huge diversity of polymeric nanoparticles with cells. This knowledge is essential to understand nanoparticle uptake and trafficking inside cells to the subcellular target structure.In this chapter, we aim to contribute to this field of knowledge by: (1) summarizing the polymeric nanoparticles properties and cellular factors that influence nanoparticle endocytosis and (2) reviewing the endocytic pathways classified as a function of nanoparticle size and as a function of the receptor playing a role. The revision of previously reported endocytic pathways for particular polymeric nanoparticles could facilitate scientist involved in this field to easily delineate efficient delivery systems based on polymeric nanoparticles.

Advances in therapeutic options for portal hypertension

Portal hypertension represents one of the major clinical consequences of chronic liver disease, having a deep impact on patients' prognosis and survival. Its pathophysiology defines a pathological increase in the intrahepatic vascular resistance as the primary factor in its development, being subsequently aggravated by a paradoxical increase in portal blood inflow. Although extensive preclinical and clinical research in the field has been developed in recent decades, no effective treatment targeting its primary mechanism has been defined. The present review critically summarizes the current knowledge in portal hypertension therapeutics, focusing on those strategies driven by the disease pathophysiology and underlying cellular mechanisms.

Hepatic fibrosis: It is time to go with hepatic stellate cell-specific therapeutic targets

Hepatic fibrosis is a pathological lesion, characterized by the progressive accumulation of extracellular matrix (ECM) in the perisinusoidal space and it is a major problem in chronic liver diseases. Phenotypic activation of hepatic stellate cells (HSC) plays a central role in the progression of hepatic fibrosis. Retardation of proliferation and clearance of activated HSCs from the injured liver is an appropriate therapeutic strategy for the resolution and treatment of hepatic fibrosis. Clearance of activated HSCs from the injured liver by autophagy inhibitors, proapoptotic agents and senescence inducers with the high affinity toward the activated HSCs may be the novel therapeutic strategy for the treatment of hepatic fibrosis in the near future.

The diagnosis of hepatic fibrosis by magnetic resonance and near-infrared imaging using dual-modality nanoparticles

Hepatic fibrosis (HF), as the only reversible process of chronic liver disease, remains a big diagnostic challenge. Development of noninvasive and effective methods to assess quantitatively early-stage HF is of great clinical importance. Compared with conventional diagnostic methods, near-infrared fluorescence imaging (NIR) and magnetic resonance imaging (MRI) could offer highly sensitive and spatial resolution signals for HF detection. However, precise detection using contrast agents is not possible. Superparamagnetic iron oxide (SPIO) nanoparticles have low toxicity, high sensitivity and excellent biocompatibility. Integration of Fe₃O₄ nanoparticles and indocyanine green (ICG), coupled with targeting ligand of integrin α_vβ₃, arginine–glycine–aspartic acid (RGD) expressed on hepatic stellate cells (HSCs), were used to detect HF. Both in vivo and in vitro results showed that the SPIO@SiO₂–ICG–RGD had high stability and low cytotoxicity. The biodistribution of SPIO@SiO₂–ICG–RGD was significantly different between mice with HF and healthy controls. SPIO@SiO₂–ICG–RGD was characterized and the results of imaging in vitro and in vivo demonstrated the expression of integrin α_vβ₃ on activated HSCs. These data suggest that our SPIO@SiO₂–ICG–RGD probe could be used for the diagnosis of early-stage HF. This new nanoprobe with a dual-modality imaging approach holds great potential for the diagnosis and classification of HF.

Schematic diagram for the synthesis of SPIO@SiO₂–ICG–RGD.

Heat shock protein 47 effects on hepatic stellate cell-associated receptors in hepatic fibrosis of Schistosoma japonicum-infected mice

The study aimed to explore the regulation of heat shock protein 47 (HSP47) on expressions of receptors associated with hepatic stellate cell (HSC) in liver fibrosis mouse models induced bySchistosoma japonicum(S. japonicum). Mouse fibroblasts (NIH/3T3) were transfected with HSP47 shRNA plasmid by lipofectamine transfection, and experimental fibrosis in HSCs was studied inS. japonicummouse models treated with HSP47 shRNAin vivo. HSP47 expression was assessed using Western blot and real-time PCR. Flow cytometry was adopted to determine the expression of cell membrane receptors. HSP47-shRNA could markedly down-regulate the expression of collagen (Col1a1 and Col3a1). The expressions of HSP47, endothelin receptor A (ETAR) and endothelin receptor B (ETBR) significantly increased in the liver tissue of infected mice. However, the expressions of ETAR and HSP47 and ETBR remarkably decreased after the administration of HSP47 shRNAin vitroandin vivo. ETAR and ETBR levels were found to be positively correlated with HSP47 expression. HSP47 might exert influence on liver fibrosis via the regulation of ETAR and ETBR.

Drug targeting to myofibroblasts: Implications for fibrosis and cancer

Myofibroblasts are the key players in extracellular matrix remodeling, a core phenomenon in numerous devastating fibrotic diseases. Not only in organ fibrosis, but also the pivotal role of myofibroblasts in tumor progression, invasion and metastasis has recently been highlighted. Myofibroblast targeting has gained tremendous attention in order to inhibit the progression of incurable fibrotic diseases, or to limit the myofibroblast-induced tumor progression and metastasis. In this review, we outline the origin of myofibroblasts, their general characteristics and functions during fibrosis progression in three major organs: liver, kidneys and lungs as well as in cancer. We will then discuss the state-of-the art drug targeting technologies to myofibroblasts in context of the above-mentioned organs and tumor microenvironment. The overall objective of this review is therefore to advance our understanding in drug targeting to myofibroblasts, and concurrently identify opportunities and challenges for designing new strategies to develop novel diagnostics and therapeutics against fibrosis and cancer.

Hepatic stellate cell-targeted therapy for hepatic fibrosis

Hepatic fibrosis is the ultimate pathological feature of all forms of chronic hepatic damage. There is currently no clinical cure for advanced liver fibrosis. Activation and proliferation of hepatic stellate cells (HSCs) is a key step in the development of liver fibrosis, and therefore, HSCs are target cells for hepatic fibrosis treatment. Targeted delivery of drugs to activated HSCs would increase the drug concentration in the liver at the sites of active fibrogenesis and avoid undesirable systemic effects. Mannose 6-phosphate modified human serum albumin, vitamin A, and hyaluronic acid are three kinds of the most investigated carriers that deliver drugs to the activated HSCs specifically. Conjugation of these carriers with molecules with anti-fibrosis activity such as angiotensin receptor blockers, activin-like kinase 5 inhibitors, Rho-kinase inhibitors, small interfering RNAs, hepatocyte growth factor gene, or nitrogen monoxide can lead to specific distribution and effects in HSCs. This review will focus on these preclinical developments of HSCs-targeted drug conjugates for the treatment of liver fibrosis.

Nanoparticles for the treatment of liver fibrosis

Chronic liver diseases represent a global health problem due to their high prevalence worldwide and the limited available curative treatment options. They can result from various causes, both infectious and noninfectious diseases. The application of nanoparticle (NP) systems has emerged as a rapidly evolving area of interest for the safe delivery of various drugs and nucleic acids for chronic liver diseases. This review presents the pathogenesis, diagnosis and the emerging nanoparticulate systems used in the treatment of chronic liver diseases caused by liver fibrosis. Activated hepatic stellate cell (HSC) is considered to be the main mechanism for liver fibrosis. Ultrasonography and magnetic resonance imaging techniques are widely used noninvasive diagnostic methods for hepatic fibrosis. A variety of nanoparticulate systems are mainly focused on targeting HSC in the treatment of hepatic fibrosis. As early liver fibrosis is reversible by current NP therapy, it is being studied in preclinical as well as clinical trials. Among various nanoparticulate systems, inorganic NPs, liposomes and nanomicelles have been widely studied due to their distinct properties to deliver drugs as well as other therapeutic moieties. Liposomal NPs in clinical trials is considered to be a milestone in the treatment of hepatic fibrosis. Currently, NP therapy for liver fibrosis is updating fast, and hopefully, it can be the future remedy for liver fibrosis.

Homing in on an intracellular target for delivery of loaded nanoparticles functionalized with a histone deacetylase inhibitor

Functionalized nanoparticles (NPs) are usually used to enhance cellular penetration for targeted drug delivery that can improve efficacy and reduce side effects. However, it is difficult to exploit intracellular targets for similar delivery applications. Herein we describe the targeted delivery of functionalized NPs by homing in on an intracellular target, histone deacetylases (HDACs). Specifically, a modified poly-lactide-co-glycolideacid (FPLGA) was yielded by conjugation with an HDAC inhibitor. Subsequently, FPLGA was used to prepare functionalized FPLGA NPs. Compared to unmodified NPs, FPLGA NPs were more efficiently uptaken or retained by MCF-7 cells and showed longer retention time intracellular. In vivo fluorescence imaging also revealed that they had a higher accumulation and a slower elimination than unmodified NPs. FPLGA NPs loaded with paclitaxel exhibited superior anticancer efficacy compared with unmodified NPs. These results offer a promising approach for intracellular drug delivery through elevating the concentration of NPs.

Novel treatment options for portal hypertension

Portal hypertension is most frequently associated with cirrhosis and is a major driver for associated complications, such as variceal bleeding, ascites or hepatic encephalopathy. As such, clinically significant portal hypertension forms the prelude to decompensation and impacts significantly on the prognosis of patients with liver cirrhosis. At present, non-selective β-blockers, vasopressin analogues and somatostatin analogues are the mainstay of treatment but these strategies are far from satisfactory and only target splanchnic hyperemia. In contrast, safe and reliable strategies to reduce the increased intrahepatic resistance in cirrhotic patients still represent a pending issue. In recent years, several preclinical and clinical trials have focused on this latter component and other therapeutic avenues. In this review, we highlight novel data in this context and address potentially interesting therapeutic options for the future.

Magnetic Resonance Elastography Shear Wave Velocity Correlates with Liver Fibrosis and Hepatic Venous Pressure Gradient in Adults with Advanced Liver Disease

Background. Portal hypertension, an elevation in the hepatic venous pressure gradient (HVPG), can be used to monitor disease progression and response to therapy in cirrhosis. Since obtaining HVPG measurements is invasive, reliable noninvasive methods of assessing portal hypertension are needed. Methods. Noninvasive markers of fibrosis, including magnetic resonance elastography (MRE) shear wave velocity, were correlated with histologic fibrosis and HVPG measurements in hepatitis C (HCV) and/or HIV-infected patients with advanced liver disease enrolled in a clinical trial of treatment with simtuzumab, an anti-LOXL2 antibody. Results. This exploratory analysis includes 23 subjects: 9 with HCV monoinfection, 9 with HIV and HCV, and 5 with HIV and nonalcoholic steatohepatitis. Median Ishak fibrosis score was 4 (range 1–6); 11 subjects (48%) had cirrhosis. Median HVPG was 6 mmHg (range 3–16). Liver stiffness measured by MRE correlated with HVPG (r = 0.64, p = 0.01), histologic fibrosis score (r = 0.71, p = 0.004), noninvasive fibrosis indices, including APRI (r = 0.81, p < 0.001), and soluble LOXL2 (r = 0.82, p = 0.001). On stepwise multivariate regression analysis, MRE was the only variable independently associated with HVPG (R² = 0.377, p = 0.02). Conclusions. MRE of the liver correlated independently with HVPG. MRE is a valid noninvasive measure of liver disease severity and may prove to be a useful tool for noninvasive portal hypertension assessment. Trial Registration Number. This trial is registered with NCT01707472.

Specific and Efficient Uptake of Surfactant-Free Poly(Lactic Acid) Nanovaccine Vehicles by Mucosal Dendritic Cells in Adult Zebrafish after Bath Immersion

Activation of mucosal immunity is a key milestone for next-generation vaccine development. Biocompatible polymer-based nanoparticles (NPs) are promising vectors and adjuvants for mucosal vaccination. However, their in vivo uptake by mucosae and their biodistribution in antigen-presenting cells (APCs) need to be better understood to optimize mucosal nanovaccine designs. Here, we assessed if APCs are efficiently targeted in a spontaneous manner by surfactant-free poly(lactic acid) nanoparticles (PLA-NPs) after mucosal administration. Combining histology and flow imaging approaches, we describe and quantify the mucosal uptake of 200 nm PLA-NPs in adult zebrafish. Following bath administration, PLA-NPs penetrated and crossed epithelial barriers from all exposed mucosae. In mucosae, PLA-NPs accumulated in APCs, which were identified as dendritic cells (DCs), macrophages, and IgZ⁺ B cells in gills and skin. PLA-NP uptake by phagocytes was specific to these cell types, as PLA-NPs were not detected in neutrophils. Importantly, quantitative analyses in gills revealed that DCs take up PLA-NPs with specifically high efficiency. This study shows that surfactant-free PLA-NPs, which display optimal biocompatibility, can spontaneously target DCs with high efficiency in vivo following mucosal administration, and highlights PLA-NPs as powerful platforms for mucosal vaccine delivery in the medical and veterinary fields, and particularly in aquaculture.

Thiol-reactive (co)polymer scaffolds comprising organic arsenical acrylamides

Well-defined polymeric arsenicals are synthesised for the first time and exploited as responsive and reactive polymer scaffolds.

Controllable NO release from Cu1.6S nanoparticle decomposition of S-nitrosoglutathiones following photothermal disintegration of polymersomes to elicit cerebral vasodilatory activity

Since the discovery of nitric oxide (NO) as a vasodilator, numerous NO therapies have been attempted to remedy disorders related to pathological vasoconstriction such as coronary artery disease. Despite the advances, clinical applications of NO therapies remain limited mainly because of the low stability of molecular NO donors (and NO molecules), and concerns about the increased oxidative stress and reduced arterial pressure associated with the systemic administration of NO. Here we design a photo-responsive polymersome with nitrosothiols and Cu_1.6S nanoparticles in its core and shell, respectively, and demonstrate the photo-triggered release of NO and its vasodilatory activity on zebrafish. Unlike conventional approaches, our design enhances the stability of NO donors and prospectively enables spatiotemporal regulation of NO release, thus minimizing the harmful effects associated with conventional NO therapies. We anticipate that such a strategy will open up new clinical applications of NO and help reveal the complex biological effects of NO in vivo.

Cellular distribution of injected PLGA-nanoparticles in the liver

The cellular fate of nanoparticles in the liver is not fully understood. Because the effectiveness and safety of nanoparticles in liver therapy depends on targeting nanoparticles to the right cell populations, this study aimed to determine a relative distribution of PLGA-nanoparticles (sizes 271±1.4 nm) among liver cells in vivo. We found that Kupffer cells were the major cells that took up nanoparticles, followed by liver sinusoidal endothelial cells and hepatic stellate cells. Nanoparticles were found in only 7% of hepatocytes. Depletion of Kupffer cells by clodronate liposomes increased nanoparticle retention in liver sinusoidal endothelial cells and hepatic stellate cells, but not in hepatocytes. It is importantly suggested that studies of drug-loaded nanoparticle delivery to the liver have to demonstrate not only uptake of nanoparticles by the target cell type but also non-uptake by other cell types to assess their effect as well as ensure their safety.

Nanoparticle-liver interactions: Cellular uptake and hepatobiliary elimination

30-99% of administered nanoparticles will accumulate and sequester in the liver after administration into the body. This results in reduced delivery to the targeted diseased tissue and potentially leads to increased toxicity at the hepatic cellular level. This review article focuses on the inter- and intra-cellular interaction between nanoparticles and hepatic cells, the elimination mechanism of nanoparticles through the hepatobiliary system, and current strategies to manipulate liver sequestration. The ability to solve the "nanoparticle-liver" interaction is critical to the clinical translation of nanotechnology for diagnosing and treating cancer, diabetes, cardiovascular disorders, and other diseases.

PAI-1 4G-4G and MTHFR 677TT in non-hepatitis C virus/hepatitis B virus-related liver cirrhosis

AIM: To evaluate the different roles of thrombophilia in patients with and without viral etiology. The thrombophilic genetic factors (THRGFs), PAI-1 4G-4G, MTHFR 677TT, V Leiden 506Q and prothrombin 20210A, were studied as risk factors in 1079 patients with liver cirrhosis (LC), enrolled from January 2000 to January 2014.

METHODS: All Caucasian LC patients consecutively observed in a fourteen-year period were included; the presence of portal vein thrombosis (PVT) and Budd Chiari syndrome (BCS) was registered. The differences between the proportions of each THRGF with regard to the presence or absence of viral etiology and the frequencies of the THRGF genotypes with those predicted in a population by the Hardy-Weinberg equilibrium were registered.

RESULTS: Four hundred and seventeen/one thousand and seventy-six patients (38.6%) showed thrombophilia: 217 PAI-1 4G-4G, 176 MTHFR C677TT, 71 V Leiden factor and 41 prothrombin G20210 A, 84 with more than 1 THRGF; 350 presented with no viral liver cirrhosis (NVLC) and 729 with, called viral liver cirrhosis (VLC), of whom 56 patients were hepatitis C virus + hepatitis B virus. PAI-1 4G-4G, MTHFR C677TT, the presence of at least one TRHGF and the presence of > 1 THRGF, were statistically more frequent in patients with NVLC vs patients with VLC: All χ² > 3.85 and P < 0.05. Patients with PVT and/or BCS with at least one TRHGF were 189/352 (53.7%). The Hardy-Weinberg of PAI-1 and MTHFR 677 genotypes deviated from that expected from a population in equilibrium in patients with NVLC (respectively χ² = 39.3; P < 0.000 and χ² = 27.94; P < 0.05), whereas the equilibrium was respected in VLC.

CONCLUSION: MTHFR 677TT was nearly twofold and PAI-1 4G-4G more than threefold more frequently found in NVLC vs patients with VLC; the Hardy-Weinberg equilibrium of these two polymorphisms confirms this data in NVLC. We suggest that PAI-1 4G-4G and MTHFR 677TT could be considered as factors of fibrosis and thrombosis mechanisms, increasing the inflammation response, and causing the hepatic fibrosis and augmented intrahepatic vascular resistance typical of LC. PAI-1 4G-4G and MTHFR 677TT screening of LC patients could be useful, mainly in those with NVLC, to identify patients in which new drug therapies based on the attenuation of the hepatic stellate cells activation or other mechanisms could be more easily evaluated.

Hepatic Shock Differential Diagnosis and Risk Factors: A Review Article

CONTEXT

Liver as an important organ has a vital role in physiological processes in the body. Different causes can disrupt normal function of liver. Factors such as hypo-perfusion, hypoxemia, infections and some others can cause hepatic injury and hepatic shock.

EVIDENCE ACQUISITION

Published research resources from 2002 to May 2015 in some databases (PubMed, Scopus, Index Copernicus, DOAJ, EBSCO-CINAHL, Science direct, Cochrane library and Google scholar and Iranian search database like SID and Iranmedex) were investigated for the present study.

RESULTS

Different causes can lead to hepatic shock. Most of these causes can be prevented by early resuscitation and treatment of underlying factors.

CONCLUSIONS

Hepatic shock is detected in ill patients, especially those with hemodynamic disorders. It can be prevented by early treatment of underlying disease. There is no definite treatment for hepatic shock and should be managed conservatively. Hepatic shock in patients can increase the mortality rate.

Nitric oxide in liver diseases

Nitric oxide (NO) and its derivatives play important roles in the physiology and pathophysiology of the liver. Despite its diverse and complicated roles, certain patterns of the effect of NO on the pathogenesis and progression of liver diseases are observed. In general, NO derived from endothelial NO synthase (eNOS) in liver sinusoidal endothelial cells (LSECs) is protective against disease development, while inducible NOS (iNOS)-derived NO contributes to pathological processes. This review addresses the roles of NO in the development of various liver diseases with a focus on recently published articles. We present here two recent advances in understanding NO-mediated signaling - nitrated fatty acids (NO2-FAs) and S-guanylation - and conclude with suggestions for future directions in NO-related studies on the liver.