Intermittent Fasting Primes the Tumor Microenvironment and Improves Nanomedicine Delivery in Hepatocellular Carcinoma.

Fasting has many health benefits, including reduced chemotherapy toxicity and improved efficacy. It is unclear how fasting affects the tumor microenvironment (TME) and tumor-targeted drug delivery. Here the effects of intermittent (IF) and short-term (STF) fasting are investigated on tumor growth, TME composition, and liposome delivery in allogeneic hepatocellular carcinoma (HCC) mouse models. To this end, mice are inoculated either subcutaneously or intrahepatically with Hep-55.1C cells and subjected to IF for 24 d or to STF for 1 d. IF but not STF significantly slows down tumor growth. IF increases tumor vascularization and decreases collagen density, resulting in improved liposome delivery. In vitro, fasting furthermore promotes the tumor cell uptake of liposomes. These results demonstrate that IF shapes the TME in HCC towards enhanced drug delivery. Finally, when combining IF with liposomal doxorubicin treatment, the antitumor efficacy of nanochemotherapy is found to be increased, while systemic side effects are reduced. Altogether, these findings exemplify that the beneficial effects of fasting on anticancer therapy outcomes go beyond modulating metabolism at the molecular level.

Biodegradable Polyimidazole Particles as Contrast Agents Produced by Direct Arylation Polymerization.

Conjugated polymer particles provide an important platform for the development of theranostic nanoagents. However, the number of biocompatible and foremost biodegradable π-conjugated polymers is limited. Imidazole is a π-conjugated motif that is abundant in biological systems. Oxidative degradation of imidazole is present in nature via enzymatic or free radical processes. In this work, we introduce polymer particles consisting purely of polyimidazole. We employ direct arylation polymerization and adapt it to a dispersion polymerization protocol to yield uniform and narrowly dispersed nanoparticles. We employ this mechanism to produce linear and cross-linked polymer particles to tune the optical properties from fluorescent to photoacoustically active. We show that the particles can be degraded by H2O2 as well as by reactive oxygen species produced by cells and we detect the degradation products. Altogether, our results suggest that polyimidazole particles represent ideal candidates for theranostic applications.

Liposomal encapsulation of dexamethasone modulates cytotoxicity, inflammatory cytokine response, and migratory properties of primary human macrophages.

The encapsulation of drugs into liposomes aims to enhance their efficacy and reduce their toxicity. Corticosteroid-loaded liposomes are currently being evaluated in patients suffering from rheumatoid arthritis, atherosclerosis, colitis, and cancer. Here, using several different fluorophore-labeled formulations, we comprehensively studied the impact of liposome encapsulation of the prototypic corticosteroid dexamethasone on various primary human cells in vitro. Liposomal dexamethasone targeted several primary cell types in a dose and time-dependent manner, but specifically reduced cytotoxicity against human fibroblasts and macrophages in comparison to the solute drug. Furthermore, macrophage maturation and polarization markers were altered. Interestingly, liposomal dexamethasone induced proinflammatory cytokine secretion (specifically TNF, IL1ß, IL6) in unstimulated cells, but reduced this response under inflammatory conditions. Monocyte and macrophage migration was significantly inhibited by dexamethasone-loaded liposomes. The findings indicate that the encapsulation of dexamethasone into liposomes modulates their cellular mechanism of action, and provides important indications for follow-up in vivo investigations. FROM THE CLINICAL EDITOR: This study investigates mechanism of action of liposomal dexamethason in the treatment of inflammatory conditions. It is concluded that liposomal dexamethasone actually induces proinflammatory cytokine secretion in unstimulated cells, but reduces the same response under inflammatory conditions. Monocyte and macrophage migration was also inhibited. The findings indicate that liposomal dexamethasone may have different mechanisms of action than its native counterpart.

YKL-40-gene polymorphism affects acute cellular rejection and fibrosis progression after transplantation for hepatitis C virus-induced liver disease.

BACKGROUND AND AIM: The development of end-stage graft disease is suspected to be partially determined by an individual genetic background. The aim of our study was to determine the prevalence of YKL-40-gene polymorphism in hepatitis C virus (HCV)-positive patients and its impact on the incidence of acute cellular rejection (ACR), graft fibrosis and antiviral treatment response. METHODS: A total of 149 patients, who underwent liver transplantation for HCV-induced liver disease, were genotyped for YKL-40 (rs4950928; G/C) by TaqMan Genotyping Assay. The results were correlated with 616 post-transplant graft biopsies regarding inflammation, fibrosis and evidence for ACR. RESULTS: No association of YKL-40-genotypes was observed regarding mean inflammation grade (P = 0.216) and antiviral treatment outcome (P = 0.733). However, the development of advanced fibrosis (F3-4) was significantly faster in patients with YKL-40-G-allele: t(CC) = 4.6 versus t(CG/GG) = 2.4 years; P = 0.006. Patients with lower fibrosis (F0-2) compared to advanced fibrosis (F3-4) received significantly more frequent dual immunosuppression (calcineurin inhibitors [CNIs]/mofetile mycophenolate [MMF] vs CNIs; P = 0.003). ACR-occurrence was associated with YKL-40-genotypes (ACR: CC = 60.4%, CG = 25.0% and GG = 14.6% vs non-ACR: CC = 74.2%, CG = 23.8% and GG = 2.0%; P = 0.009) and with gender compatibility between donor and recipient (P = 0.012). CONCLUSION: Fibrosis progression and ACR-incidence after transplantation for HCV-induced liver disease seem to be under genetic control. The negative impact of G-allele on post-transplant events observed in our study, deserves attention and should be verified in larger liver transplantation-cohorts.

Microgels as Platforms for Antibody-Mediated Cytokine Scavenging.

Therapeutic antibodies are the key treatment option for various cytokine-mediated diseases, such as rheumatoid arthritis, psoriasis, and inflammatory bowel disease. However, systemic injection of these antibodies can cause side effects and suppress the immune system. Moreover, clearance of therapeutic antibodies from the blood is limiting their efficacy. Here, water-swollen microgels are produced with a size of 25 µm using droplet-based microfluidics. The microgels are functionalized with TNFα antibodies to locally scavenge the pro-inflammatory cytokine TNFα. Homogeneous distribution of TNFα-antibodies is shown throughout the microgel network and demonstrates specific antibody-antigen binding using confocal microscopy and FLIM-FRET measurements. Due to the large internal accessibility of the microgel network, its capacity to bind TNFα is extremely high. At a TNFα concentration of 2.5 µg mL-1 , the microgels are able to scavenge 88% of the cytokine. Cell culture experiments reveal the therapeutic potential of these microgels by protecting HT29 colorectal adenocarcinoma cells from TNFα toxicity and resulting in a significant reduction of COX II and IL8 production of the cells. When the microgels are incubated with stimulated human macrophages, to mimic the in vivo situation of inflammatory bowel disease, the microgels scavenge almost all TNFα that is produced by the cells.

Rapid and strong antiviral activity of the non-nucleosidic NS5B polymerase inhibitor BI 207127 in combination with peginterferon alfa 2a and ribavirin.

BACKGROUND & AIMS: BI 207127 is a potent non-nucleoside hepatitis C virus (HCV) NS5B polymerase inhibitor in vitro. METHODS: In this double-blind, placebo-controlled study, 57 HCV genotype (GT)-1 patients (n=27 treatment-naïve [TN]; n=30 treatment-experienced [TE]) with compensated liver disease were randomised for 28-day treatment with 400, 600, or 800 mg BI 207127 three times daily (TID) or placebo (only TN) in combination with peginterferon alfa 2a and ribavirin (PegIFN/RBV). Plasma HCV RNA was measured by Roche COBAS TaqMan assay. RESULTS: HCV RNA decreased in a dose-dependent manner with little difference between 600 mg (TN 5.6 log(10), TE 4.2 log(10)) and 800 mg (TN 5.4 log(10), TE 4.5 log(10)). Rapid virological response (RVR; HCV RNA <15 IU/ml) at day 28 occurred in 11/19 TN and 4/30 TE patients treated with BI 207127. GT-1b patients had stronger reductions in HCV RNA than GT-1a (RVR: TN 64% vs. 43%; TE 33% vs. 5%). There were no breakthroughs (HCV RNA rebound >1 log(10) from nadir) in the TN groups, whereas 3/30 TE patients experienced breakthrough due to P495-mutations. Gastrointestinal adverse events (AEs) and rash were the major AEs and most frequent at higher doses. One and four patients discontinued due to AEs in the 600 and 800 mg groups, respectively. Overall, tolerability was good and better at 600 mg than 800 mg. CONCLUSIONS: BI 207127 in combination with PegIFN/RBV demonstrated strong antiviral activity with a favourable safety and tolerability profile. The best benefit/risk ratio was observed at 600 mg.

The oral-gut axis: Salivary and fecal microbiome dysbiosis in patients with inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a group of chronic inflammatory disorders that fall into two main categories: Crohn's disease (CD) and ulcerative colitis (UC). The gastrointestinal tract extends from the mouth to the anus and harbors diverse bacterial communities. Several sequencing-based studies have identified an intestinal enrichment of oral-associated bacteria and demonstrated their ability to induce intestinal inflammation in mice, suggesting that intestinal pathobionts originate from the oral cavity, particularly members of the genus Streptococcus. This study aimed to investigate the composition of the salivary and fecal microbiome of IBD patients (n = 14) compared to healthy controls (n = 12) and to determine the abundance of common bacterial taxa in both niches. Metagenomic DNA was extracted from saliva and fecal samples, and the 16S rRNA gene was targeted for sequencing. Our results revealed that the overall microbial composition of saliva was significantly altered in the IBD patients compared to the control subjects (p = 0.038). At the genus level, Veillonella and Prevotella were highly abundant in IBD (median: 25.4% and 22.2%, respectively) compared to the control group (17.9% and 13.4%, respectively). In contrast, Neisseria, Streptococcus, Haemophilus, and Fusobacterium were associated with a healthy gut state. Regarding the fecal microbiome, the IBD group had a significantly higher abundance of Clostridium sensu stricto 1 and Escherichia-Shigella (both comprising pathogenic bacteria) compared with the control group. Members of both bacterial groups have previously been shown to positively correlate with intestinal inflammation and high expression of pro-inflammatory cytokines that disrupt intestinal barrier integrity. In addition, we demonstrate that the increased abundance of Clostridium sensu stricto 1 and Escherichia-Shigella has also been associated with significant upregulation of certain metabolic pathways in the feces of the IBD group, including bacterial invasion of epithelial cells. Streptococcus was the only common genus detected in both the salivary and fecal microbiome and represented the oral-gut axis in our study. Using culture-based methods, we isolated 57 and 91 Streptococcus strains from saliva as well as 40 and 31 strains from fecal samples of the controls and IBD patients, respectively. The phylogenetic tree of streptococci based on sodA sequences revealed several patient-specific clusters comprising salivary and fecal streptococcal isolates from the same patient and belonging to the same species, suggesting that the oral cavity is an endogenous reservoir for intestinal strains.

Microgels Sopping Up Toxins-GM1a-Functionalized Microgels as Scavengers for Cholera Toxin.

Vibrio cholerae is a Gram-negative bacterium that causes secretory diarrhea and constitutes a major health threat in the industrialized world and even more in developing countries. Its main virulence factor is the cholera toxin, which is internalized by intestinal epithelial cells after binding to the glycosphingolipid receptor GM1a on their apical surface. A potential future solution to dampen complications of cholera infection is by scavenging the cholera toxin by presenting competitive binding motifs to diminish the in vivo toxicity of V. cholerae. Here, we generate GM1a-functionalized and biocompatible microgels with diameters of 20 µm using drop-based microfluidics. The microgels are designed to exhibit a mesoporous and widely meshed network structure, allowing diffusion of the toxin protein deep into the microgel scavengers. Flow cytometry demonstrates strong and multivalent binding at high capacity of these microgels to the binding domain of the cholera toxin. Cell culture-based assays reveal the ability of these microgels to scavenge and retain the cholera toxin in direct binding competition to colorectal cells. This ability is evidenced by suppressed cyclic adenosine monophosphate production as well as reduced vacuole formation in mucus-forming colorectal HT-29 cells. Therefore, glycan-functionalized microgels show great potential as a non-antibiotic treatment for toxin-mediated infectious disorders.

Liver fibrosis affects the targeting properties of drug delivery systems to macrophage subsets in vivo.

Myeloid immune cells promote inflammation and fibrosis in chronic liver diseases. Drug delivery systems, such as polymers, liposomes and microbubbles, efficiently target myeloid cells in healthy liver, but their targeting properties in hepatic fibrosis remain elusive. We therefore studied the biodistribution of three intravenously injected carrier material, i.e. 10 nm poly(N-(2-hydroxypropyl)methacrylamide) polymers, 100 nm PEGylated liposomes and 2000 nm poly(butyl cyanoacrylate) microbubbles, in two fibrosis models in immunocompetent mice. While whole-body imaging confirmed preferential hepatic uptake even after induction of liver fibrosis, flow cytometry and immunofluorescence analysis revealed markedly decreased carrier uptake by liver macrophage subsets in fibrosis, particularly for microbubbles and polymers. Importantly, carrier uptake co-localized with immune infiltrates in fibrotic livers, corroborating the intrinsic ability of the carriers to target myeloid cells in areas of inflammation. Of the tested carrier systems liposomes had the highest uptake efficiency among hepatic myeloid cells, but the lowest specificity for cellular subsets. Hepatic fibrosis affected carrier uptake in liver and partially in spleen, but not in other tissues (blood, bone marrow, lung, kidney). In conclusion, while drug carrier systems target distinct myeloid cell populations in diseased and healthy livers, hepatic fibrosis profoundly affects their targeting efficiency, supporting the need to adapt nanomedicine-based approaches in chronic liver disease.

Sustained HCV-RNA response and hepatitis Bs seroconversion after individualized antiviral therapy with pegylated interferon alpha plus ribavirin and active vaccination in a hepatitis C virus/hepatitis B virus-coinfected patient.

Hepatitis B virus (HBV) and hepatitis C virus (HCV) coinfection is frequently associated with progressive liver disease. Treatment options are limited and no data on the efficacy of pegylated interferon (PEG-IFN) plus ribavirin therapy are available. We report a case of a 49-year-old woman with chronic hepatitis B and C who was scheduled for a 48 weeks course of PEG-IFNalpha-2b plus ribavirin therapy. She had HCV genotype 2 infection and was negative for HBV-DNA and HBe antigen before treatment. Although the HCV-RNA response was rapid until week 12, hepatitis B surface antigen (HBsAg) levels showed a more linear decline. At week 48, HBsAg was still positive, however, with very low levels of only 0.06 IU/ml. Treatment was therefore continued for another 4 weeks combined with active HBV immunization until HBs seroconversion occurred. Forty-three weeks after treatment, the patient showed a robust HBs seroconversion (anti-HBs of 260 IU/ml) and a sustained HCV-RNA response. This case highlights that combination therapy of PEG-IFNalpha-2b with ribavirin of HBV/HCV-coinfected individuals cannot only induce a sustained HCV-RNA response but also HBsAg seroconversion in single patients. Monitoring of HBsAg levels can be useful in individualizing optimal treatment duration in HBV-infected patients.

Targeting distinct myeloid cell populations in vivo using polymers, liposomes and microbubbles.

Identifying intended or accidental cellular targets for drug delivery systems is highly relevant for evaluating therapeutic and toxic effects. However, limited knowledge exists on the distribution of nano- and micrometer-sized carrier systems at the cellular level in different organs. We hypothesized that clinically relevant carrier materials, differing in composition and size, are able to target distinct myeloid cell subsets that control inflammatory processes, such as macrophages, neutrophils, monocytes and dendritic cells. Therefore, we analyzed the biodistribution and in vivo cellular uptake of intravenously injected poly(N-(2-hydroxypropyl) methacrylamide) polymers, PEGylated liposomes and poly(butyl cyanoacrylate) microbubbles in mice, using whole-body imaging (computed tomography - fluorescence-mediated tomography), intra-organ imaging (intravital multi-photon microscopy) and cellular analysis (flow cytometry of blood, liver, spleen, lung and kidney). While the three carrier materials shared accumulation in tissue macrophages in liver and spleen, they notably differed in uptake by other myeloid subsets. Kupffer cells and splenic red pulp macrophages rapidly take up microbubbles. Liposomes efficiently reach dendritic cells in liver, lung and kidney. Polymers exhibit the longest circulation half-life and target endothelial cells in the liver, neutrophils and alveolar macrophages. The identification of such previously unrecognized target cell populations might open up new avenues for more efficient drug delivery.

Fluorescent cell-traceable dexamethasone-loaded liposomes for the treatment of inflammatory liver diseases.

Liposomes are routinely used carrier materials for delivering drug molecules to pathological sites. Besides in tumors and inflammatory sites, liposomes also strongly accumulate in liver and spleen. The potential of using liposomes to treat acute and chronic liver disorders, however, has not yet been evaluated. We here explored the therapeutic potential of dexamethasone (Dex)-loaded liposomes for inflammatory liver diseases, using experimental models of acute and chronic liver injury in mice. Fluorescently labeled liposomes predominantly accumulated in hepatic phagocytes, but also in T cells. Importantly, Dex-loaded liposomes reduced T cells in blood and liver, more effectively than free Dex, and endorsed the anti-inflammatory polarization of hepatic macrophages. In experimental chronic liver damage, Dex-loaded liposomes significantly reduced liver injury and liver fibrosis. In immune-mediated acute hepatitis Dex-loaded liposomes, but not free Dex, significantly reduced disease severity. T cells, not macrophages, were significantly depleted by Dex liposomes in liver disease models in vivo, as further supported by mechanistic cell death in vitro studies. Our data indicate that Dex liposomes may be an interesting treatment option for liver diseases, in particular for immune-mediated hepatitis. The depletion of T cells might represent the major mechanism of action of Dex liposomes, rather than their macrophage-polarizing activities.

Tumor necrosis factor-α and oral inflammation in patients with Crohn disease.

BACKGROUND: Crohn disease (CD) is a chronic inflammatory bowel disease often accompanied by periodontal symptoms. Based on its function in immune response, tumor necrosis factor (TNF)-α and its genetic variants have been discussed as risk indicators in inflammatory processes. Therefore, the aim of the present study is to investigate the impact of TNF-α polymorphisms on periodontal parameters and inflammatory lesions of oral mucosa as a characteristic of CD. METHODS: A total of 142 patients with CD were included in the study. Oral soft tissue alterations and periodontal parameters were assessed. Genotypes, alleles, and haplotypes of TNF-α polymorphisms (rs1800629, cDNA-308G > A; and rs361525, cDNA-238G > A) were determined by polymerase chain reaction with sequence-specific primers (PCR-SSP). RESULTS: Patients with CD who exhibit more severe oral soft tissue alterations were significantly more often A allele carriers of rs361525 than G allele carriers (14.2% versus 2.2%; P <0.001). Furthermore, A allele carriers had a higher mean periodontal probing depth (P <0.05), mean clinical attachment level (P <0.05), and sites with bleeding on probing (not significant). Similar results were obtained when evaluating A allele-containing genotypes (AG + AA) and haplotypes (GA). In multivariate analyses considering age, sex, smoking, and medication as confounders, the A allele was proven to be an independent risk indicator for oral soft tissue alterations in patients with CD. No genotype-dependent influence of rs1800629 was observed. CONCLUSION: The TNF-α A allele of rs361525 represents a significant risk indicator for oral soft tissue alterations in patients with CD.

No beneficial effect of all-trans retinoic acid in previous non-responder patients with chronic hepatitis C: the ATRACTION study, a phase II randomised trial.

BACKGROUND: Preclinical data suggested all-trans retinoic acid (tretinoin) as a potential antiviral agent against chronic hepatitis C infection. AIMS: To assess efficacy, safety, and tolerability of tretinoin in combination with peg-interferon and ribavirin in genotype-1 infected patients with prior non-response. METHOD: We performed an open-label multicentre clinical trial. Patients were randomised to either receive additional tretinoin (45mg/m(2)/day) for 12 weeks (arm A), or peg-interferon and ribavirin alone (arm B). Primary endpoint was the slope of the third phase of viral decline (Mδ) as determined in an established kinetic model known to correlate with treatment outcome. Secondary endpoints were additional kinetic parameters, viral response rates, safety, and tolerability. RESULTS: 27 patients in arm A and 30 patients in arm B were treated per protocol until week 12. Viral kinetic parameters did not differ. Rates of early virological response (>2log10 drop at week 12) were similar (10/27 versus 11/30 patients). In arm A, patients experienced a higher rate and intensity of adverse events, most commonly skin and mucosal dryness, and headache. CONCLUSION: Addition of tretinoin was safe and acceptably well tolerated. However, it did not influence viral kinetics and thus cannot be further considered as a treatment option.

The HEP-NET B/C co-infection trial: A prospective multicenter study to investigate the efficacy of pegylated interferon-alpha2b and ribavirin in patients with HBV/HCV co-infection.

BACKGROUND/AIMS: The efficacy of pegylated interferon alpha and ribavirin in HBV/HCV co-infected patients is unknown. METHODS: Nineteen patients with chronic HBV/HCV co-infection (HBsAg and HCV-RNA positive; 10 HCV-genotype 1; 9 HCV-genotype 2 or 3) were included in this prospective multicenter pilot study. Baseline HBV-DNA was negative in 13 individuals. All patients received weight-adjusted PEG-IFN-alpha2b and ribavirin for 48 weeks. RESULTS: In the intent-to-treat analysis, a biochemical and an HCV-RNA response were observed in 12 and 14 patients, respectively (63% and 74%). At the end of the treatment as well as at the end of the follow-up the HCV-RNA response was 93% (14/15) in patients adherent to therapy (86% in genotype 1 and 100% in genotypes 2 and 3 infection). Two of the five initially HBV-DNA positive patients with follow-up available were HBV-DNA negative at follow-up week 24. In contrast, HBV-DNA became detectable after the clearance of HCV in four initially HBV-DNA negative patients. CONCLUSIONS: Combination therapy with PEG-IFN-a2b and ribavirin is highly effective in inducing a virological response concerning HCV in patients with HBV/HCV co-infection. However, HBV replication may increase after the clearance of HCV and thus close monitoring for both the viruses is recommended even in patients with initially undetectable HBV-DNA.

Functional inhibition of NF-kappaB signal transduction in alphavbeta3 integrin expressing endothelial cells by using RGD-PEG-modified adenovirus with a mutant IkappaB gene.

In order to selectively block nuclear factor kappaB (NF-kappaB)-dependent signal transduction in angiogenic endothelial cells, we constructed an alphavbeta3 integrin specific adenovirus encoding dominant negative IkappaB (dnIkappaB) as a therapeutic gene. By virtue of RGD modification of the PEGylated virus, the specificity of the cell entry pathway of adenovirus shifted from coxsacki-adenovirus receptor dependent to alphavbeta3 integrin dependent entry. The therapeutic outcome of delivery of the transgene into endothelial cells was determined by analysis of cellular responsiveness to tumor necrosis factor (TNF)-alpha. Using real time reverse transcription PCR, mRNA levels of the cell adhesion molecules E-selectin, vascular cell adhesion molecule (VCAM)-1 and intercellular adhesion molecule (ICAM)-1, the cytokines/growth factors IL-6, IL-8 and vascular endothelial growth factor (VEGF)-A, and the receptor tyrosine kinase Tie-2 were assessed. Furthermore, levels of ICAM-1 protein were determined by flow cytometric analysis. RGD-targeted adenovirus delivered the dnIkappaB via alphavbeta3 to become functionally expressed, leading to complete abolishment of TNF-alpha-induced up-regulation of E-selectin, ICAM-1, VCAM-1, IL-6, IL-8, VEGF-A and Tie-2. The approach of targeted delivery of dnIkappaB into endothelial cells presented here can be employed for diseases such as rheumatoid arthritis and inflammatory bowel disease where activation of NF-kappaB activity should be locally restored to basal levels in the endothelium.