• Enhanced uptake and siRNA-mediated knockdown of a biologically relevant gene using cyclodextrin polyrotaxane

      Dandekar, P.; Jain, R.; Keil, M.; Loretz, B.; Koch, M.; Wenz, G.; Lehr, C.-M.; Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS),Saarland 9 University, 66123 Saarbrücken, Germany. (2015)
    • Expression and Activity of Breast Cancer Resistance Protein (BCRP/ABCG2) in Human Distal Lung Epithelial Cells In Vitro.

      Nickel, Sabrina; Selo, Mohammed Ali; Fallack, Juliane; Clerkin, Caoimhe G; Huwer, Hanno; Schneider-Daum, Nicole; Lehr, Claus Michael; Ehrhardt, Carsten; Helmholtz Institut für Pharmaceutischr Forschung Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany. (2017-05-03)
      Breast cancer resistance protein (BCRP/ABCG2) has previously been identified with high expression levels in human lung. The subcellular localisation and functional activity of the transporter in lung epithelia, however, remains poorly investigated. The aim of this project was to study BCRP expression and activity in freshly isolated human alveolar epithelial type 2 (AT2) and type 1-like (AT1-like) cells in primary culture, and to compare these findings with data obtained from the NCI-H441 cell line.
    • Expression and function of the epithelial sodium channel δ-subunit in human respiratory epithelial cells in vitro.

      Schwagerus, Elena; Sladek, Svenja; Buckley, Stephen T; Armas-Capote, Natalia; Alvarez de la Rosa, Diego; Harvey, Brian J; Fischer, Horst; Illek, Beate; Huwer, Hanno; Schneider-Daum, Nicole; et al. (2015-11)
      Using human airway epithelial cell lines (i.e. NCI-H441 and Calu-3) as well as human alveolar epithelial type I-like (ATI) cells in primary culture, we studied the contribution of the epithelial sodium channel δ-subunit (δ-ENaC) to transepithelial sodium transport in human lung in vitro. Endogenous δ-ENaC protein was present in all three cell types tested; however, protein abundance was low, and no expression was detected in the apical cell membrane of these cells. Similarly, known modulators of δ-ENaC activity, such as capsazepine and icilin (activators) and Evans blue (inhibitor), did not show effects on short-circuit current (I SC), suggesting that δ-ENaC is not involved in the modulation of transcellular sodium absorption in NCI-H441 cell monolayers. Over-expression of δ-ENaC in NCI-H441 cells resulted in detectable protein expression in the apical cell membrane, as well as capsazepine and icilin-stimulated increases in I SC that were effectively blocked by Evans blue and that were consistent with δ-ENaC activation and inhibition, respectively. Consequently, these observations suggest that δ-ENaC expression is low in NCI-H441, Calu-3, and ATI cells and does not contribute to transepithelial sodium absorption.
    • Extracellular vesicles protect glucuronidase model enzymes during freeze-drying.

      Frank, Julia; Richter, Maximilian; de Rossi, Chiara; Lehr, Claus-Michael; Fuhrmann, Kathrin; Fuhrmann, Gregor; HIPS, Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus 8.1, 66123 Saarbrücken, Germany. (2018-08-17)
      Extracellular vesicles (EVs) are natural nanoparticles that play important roles in intercellular communication and are increasingly studied for biosignalling, pathogenesis and therapy. Nevertheless, little is known about optimal conditions for their transfer and storage, and the potential impact on preserving EV-loaded cargoes. We present the first comprehensive stability assessment of different widely available types of EVs during various storage conditions including -80 °C, 4 °C, room temperature, and freeze-drying (lyophilisation). Lyophilisation of EVs would allow easy handling at room temperature and thus significantly enhance their expanded investigation. A model enzyme, β-glucuronidase, was loaded into different types of EVs derived from mesenchymal stem cells, endothelial cells and cancer cells. Using asymmetric flow field-flow fractionation we proved that the model enzyme is indeed stably encapsulated into EVs. When assessing enzyme activity as indicator for EV stability, and in comparison to liposomes, we show that EVs are intrinsically stable during lyophilisation, an effect further enhanced by cryoprotectants. Our findings provide new insight for exploring lyophilisation as a novel storage modality and we create an important basis for standardised and advanced EV applications in biomedical research.
    • Focused Ultrasound as a Scalable and Contact-Free Method to Manufacture Protein-Loaded PLGA Nanoparticles.

      Schiller, Stefan; Hanefeld, Andrea; Schneider, Marc; Lehr, Claus-Michael; Helmholtz Institute for Pharmaceutical Research Saarland,Saarbru¨ cken, Saarland 66123, Germany. (2015-09)
      Although nanomaterials are under investigation for a very broad range of medical applications, only a small fraction of these are already commercialized or in clinical development. A major challenge for the translation of nanomedicines into the clinic is the missing scalability of the available lab scale preparation methods and, ultimately, non-identical samples during early and late research.
    • Freeze-drying as a preserving preparation technique for in vitro testing of human skin.

      Franzen, Lutz; Vidlářová, Lucie; Kostka, Karl-Heinz; Schaefer, Ulrich F; Windbergs, Maike (2013-01)
      In vitro testing of drugs with excised human skin is a valuable prerequisite for clinical studies. However, the analysis of excised human skin presents several obstacles. Ongoing drug diffusion, microbial growth and changes in hydration state influence the results of drug penetration studies. In this work, we evaluate freeze-drying as a preserving preparation method for skin samples to overcome these obstacles. We analyse excised human skin before and after freeze-drying and compare these results with human skin in vivo. Based on comprehensive thermal and spectroscopic analysis, we demonstrate comparability to in vivo conditions and exclude significant changes within the skin samples due to freeze-drying. Furthermore, we show that freeze-drying after skin incubation with drugs prevents growth of drug crystals on the skin surface due to drying effects. In conclusion, we introduce freeze-drying as a preserving preparation technique for in vitro testing of human skin.
    • High-throughput phenotyping by applying digital morphometrics and fluorescence induction curves in seeds to identifying variations: A case study of Annona (Annonaceae) species

      Pontes, Montcharles S.; Montefusco-Pereira, Carlos V.; Misra, Biswapriya B.; Ribeiro-Junior, Howard L.; Graciano, Daniela E.; Santos, Jaqueline S.; Nobrega, Michele A.S.; Fernandes, Shaline S.L.; Caires, Anderson R.L.; Santiago, Etenaldo F.; et al.
    • Human alveolar epithelial cells expressing tight junctions to model the air-blood barrier.

      Kuehn, Anna; Kletting, Stephanie; de Souza Carvalho-Wodarz, Cristiane; Repnik, Urska; Griffiths, Gareth; Fischer, Ulrike; Meese, Eckart; Huwer, Hanno; Wirth, Dagmar; May, Tobias; et al. (2016-03-17)
      This paper describes a new human alveolar epithelial cell line (hAELVi - human Alveolar Epithelial Lentivirus immortalized) with type I-like characteristics and functional tight junctions, suitable to model the air-blood barrier of the peripheral lung. Primary human alveolar epithelial cells were immortalized by a novel regimen, grown as monolayers on permeable filter supports and characterized morphologically, biochemically and biophysically. hAELVi cells maintain the capacity to form tight intercellular junctions, with high trans-epithelial electrical resistance (> 1000 Ω*cm²). The cells could be kept in culture over several days, up to passage 75, under liquid-liquid as well as air-liquid conditions. Ultrastructural analysis and real time PCR revealed type I-like cell properties, such as the presence of caveolae, expression of caveolin-1, and absence of surfactant protein C. Accounting for the barrier properties, inter-digitations sealed with tight junctions and desmosomes were also observed. Low permeability of the hydrophilic marker sodium fluorescein confirmed the suitability of hAELVi cells for in vitro transport studies across the alveolar epithelium. These results suggest that hAELVi cells reflect the essential features of the air-blood barrier, as needed for an alternative to animal testing to study absorption and toxicity of inhaled drugs, chemicals and nanomaterials.
    • Impact of PEG and PEG-b-PAGE modified PLGA on nanoparticle formation, protein loading and release.

      Rietscher, René; Czaplewska, Justyna A; Majdanski, Tobias C; Gottschaldt, Michael; Schubert, Ulrich S; Schneider, Marc; Lehr, Claus-Michael (2016-03-16)
      The effect of modifying the well-established pharmaceutical polymer PLGA by different PEG-containing block-copolymers on the preparation of ovalbumin (OVA) loaded PLGA nanoparticles (NPs) was studied. The used polymers contained poly(d,l-lactic-co-glycolic acid) (PLGA), polyethylene glycol (PEG) and poly(allyl glycidyl ether) (PAGE) as building blocks. The double emulsion technique yielded spherical NPs in the size range from 170 to 220nm (PDI<0.15) for all the differently modified polymers, allowing to directly compare protein loading of and release. PEGylation is usually believed to increase the hydrophilic character of produced particles, favoring encapsulation of hydrophilic substances. However, in this study simple PEGylation of PLGA had only a slight effect on protein release. In contrast, incorporating a PAGE block between the PEG and PLGA units, also eventually enabling active targeting introducing a reactive group, led to a significantly higher loading (+25%) and release rate (+100%), compared to PLGA and PEG-b-PLGA NPs.
    • Improved input parameters for diffusion models of skin absorption.

      Hansen, Steffi; Lehr, Claus-Michael; Schaefer, Ulrich F; Drug Delivery, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz-Center for Infection Research (HZI), Saarbruecken, Germany. Steffi.hansen@helmholtz-hzi.de (2013-02)
      To use a diffusion model for predicting skin absorption requires accurate estimates of input parameters on model geometry, affinity and transport characteristics. This review summarizes methods to obtain input parameters for diffusion models of skin absorption focusing on partition and diffusion coefficients. These include experimental methods, extrapolation approaches, and correlations that relate partition and diffusion coefficients to tabulated physico-chemical solute properties. Exhaustive databases on lipid-water and corneocyte protein-water partition coefficients are presented and analyzed to provide improved approximations to estimate lipid-water and corneocyte protein-water partition coefficients. The most commonly used estimates of lipid and corneocyte diffusion coefficients are also reviewed. In order to improve modeling of skin absorption in the future diffusion models should include the vertical stratum corneum heterogeneity, slow equilibration processes, the absorption from complex non-aqueous formulations, and an improved representation of dermal absorption processes. This will require input parameters for which no suitable estimates are yet available.
    • In vitro and in vivo comparison between poractant alfa and the new generation synthetic surfactant CHF5633.

      Ricci, Francesca; Murgia, Xabier; Razzetti, Roberta; Pelizzi, Nicola; Salomone, Fabrizio; Helmholtz Institut für pharmazeutische Forschung Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany. (2017-02)
      CHF5633 is a new generation synthetic surfactant containing both SP-B and SP-C analogues developed for the treatment of respiratory distress syndrome. Here, the optimal dose and its performance in comparison to the animal-derived surfactant poractant alfa were investigated.
    • In vitro surfactant and perfluorocarbon aerosol deposition in a neonatal physical model of the upper conducting airways.

      Goikoetxea, Estibalitz; Murgia, Xabier; Serna-Grande, Pablo; Valls-i-Soler, Adolf; Rey-Santano, Carmen; Rivas, Alejandro; Antón, Raúl; Basterretxea, Francisco J; Miñambres, Lorena; Méndez, Estíbaliz; et al. (2014)
      Aerosol delivery holds potential to release surfactant or perfluorocarbon (PFC) to the lungs of neonates with respiratory distress syndrome with minimal airway manipulation. Nevertheless, lung deposition in neonates tends to be very low due to extremely low lung volumes, narrow airways and high respiratory rates. In the present study, the feasibility of enhancing lung deposition by intracorporeal delivery of aerosols was investigated using a physical model of neonatal conducting airways.
    • In vitro toxicological screening of nanoparticles on primary human endothelial cells and the role of flow in modulating cell response.

      Ucciferri, Nadia; Collnot, Eva-Marie; Gaiser, Birgit K; Tirella, Annalisa; Stone, Vicki; Domenici, Claudio; Lehr, Claus-Michael; Ahluwalia, Arti (2014-09)
      After passage through biological barriers, nanomaterials inevitably end up in contact with the vascular endothelium and can induce cardiovascular damage. In this study the toxicity and sub-lethal effects of six types of nanoparticle, including four of industrial and biomedical importance, on human endothelial cells were investigated using different in vitro assays. The results show that all the particles investigated induce some level of damage to the cells and that silver particles were most toxic, followed by titanium dioxide. Furthermore, endothelial cells were shown to be more susceptible when exposed to silver nanoparticles under flow conditions in a bioreactor. The study underlines that although simple in vitro tests are useful to screen compounds and to identify the type of effect induced on cells, they may not be sufficient to define safe exposure limits. Therefore, once initial toxicity screening has been conducted on nanomaterials, it is necessary to develop more physiologically relevant in vitro models to better understand how nanomaterials can impact on human health.
    • In vivo genome editing using nuclease-encoding mRNA corrects SP-B deficiency.

      Mahiny, Azita J; Dewerth, Alexander; Mays, Lauren E; Alkhaled, Mohammed; Mothes, Benedikt; Malaeksefat, Emad; Loretz, Brigitta; Rottenberger, Jennifer; Brosch, Darina M; Reautschnig, Philipp; et al. (2015-06)
    • Increased survival and proliferation of the epidemic strain Mycobacterium abscessus subsp. massiliense CRM0019 in alveolar epithelial cells.

      Ribeiro, Giovanni Monteiro; Matsumoto, Cristianne Kayoko; Real, Fernando; Teixeira, Daniela; Duarte, Rafael Silva; Mortara, Renato Arruda; Leão, Sylvia Cardoso; de Souza Carvalho-Wodarz, Cristiane; Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Universitycampus E8.1, 66123 Saarbrücken, Germany. (2017-09-13)
      Outbreaks of infections caused by rapidly growing mycobacteria have been reported worldwide generally associated with medical procedures. Mycobacterium abscessus subsp. massiliense CRM0019 was obtained during an epidemic of postsurgical infections and was characterized by increased persistence in vivo. To better understand the successful survival strategies of this microorganism, we evaluated its infectivity and proliferation in macrophages (RAW and BMDM) and alveolar epithelial cells (A549). For that, we assessed the following parameters, for both M. abscessus CRM0019 as well as the reference strain M. abscessus ATCC 19977: internalization, intracellular survival for up 3 days, competence to subvert lysosome fusion and the intracellular survival after cell reinfection.
    • Inhalable Clarithromycin Microparticles for Treatment of Respiratory Infections.

      Dimer, Frantiescoli; de Souza Carvalho-Wodarz, Cristiane; Haupenthal, Jörg; Hartmann, Rolf; Lehr, Claus-Michael; Helmholtz-Institute for Pharmaceutical 8 Research Saarland (HIPS),Saarland 9 University, 66123 Saarbrücken, Germany. (2015-12)
      The aim of this work was to develop clarithromycin microparticles (CLARI-MP) and evaluate their aerodynamic behavior, safety in bronchial cells and anti-bacterial efficacy.
    • Interaction of metal oxide nanoparticles with lung surfactant protein A.

      Schulze, Christine; Schaefer, Ulrich F; Ruge, Christian A; Wohlleben, Wendel; Lehr, Claus-Michael; Department of Biopharmaceutics and Pharmaceutical Technology, Saarland University, Saarbruecken, Germany. chr.schulze@mx.uni-saarland.de (2011-04)
      The alveolar lining fluid (ALF) covering the respiratory epithelium of the deep lung is the first biological barrier encountered by nanoparticles after inhalation. We here report for the first time significant differences for metal oxide nanoparticles to the binding of surfactant protein A (SP-A), the predominant protein component of ALF. SP-A is a physiologically most relevant protein and provides important biological signals. Also, it is involved in the lung's immune defence, controlling e.g. particle binding, uptake or transcytosis by epithelial cells and macrophages. In our study, we could prove different particle-protein interaction for eight different nanoparticles, whereas particles of the same bulk material revealed different adsorption patterns. In contrast to other proteins as bovine serum albumin (BSA), SP-A does not seem to significantly deagglomerate large agglomerates of particles, indicating different adsorption mechanisms as in the well-investigated model protein BSA. These findings may have important consequences for biological fate and toxicological effects of inhaled nanomaterials.
    • Kinetics of mRNA delivery and protein translation in dendritic cells using lipid-coated PLGA nanoparticles.

      Yasar, Hanzey; Biehl, Alexander; De Rossi, Chiara; Koch, Marcus; Murgia, Xabi; Loretz, Brigitta; Lehr, Claus-Michael; HIPS, Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus 8.1, 66123 Saarbrücken, Germany. (2018-09-19)
      Messenger RNA (mRNA) has gained remarkable attention as an alternative to DNA-based therapies in biomedical research. A variety of biodegradable nanoparticles (NPs) has been developed including lipid-based and polymer-based systems for mRNA delivery. However, both systems still lack in achieving an efficient transfection rate and a detailed understanding of the mRNA transgene expression kinetics. Therefore, quantitative analysis of the time-dependent translation behavior would provide a better understanding of mRNA's transient nature and further aid the enhancement of appropriate carriers with the perspective to generate future precision nanomedicines with quick response to treat various diseases. A lipid-polymer hybrid system complexed with mRNA was evaluated regarding its efficiency to transfect dendritic cells (DCs) by simultaneous live cell video imaging of both particle uptake and reporter gene expression. We prepared and optimized NPs consisting of poly (lactid-co-glycolid) (PLGA) coated with the cationic lipid 1, 2-di-O-octadecenyl-3-trimethylammonium propane abbreviated as LPNs. An earlier developed polymer-based delivery system (chitosan-PLGA NPs) served for comparison. Both NPs types were complexed with mRNA-mCherry at various ratios. While cellular uptake and toxicity of either NPs was comparable, LPNs showed a significantly higher transfection efficiency of ~ 80% while chitosan-PLGA NPs revealed only ~ 5%. Further kinetic analysis elicited a start of protein translation after 1 h, with a maximum after 4 h and drop of transgene expression after 48 h post-transfection, in agreement with the transient nature of mRNA. Charge-mediated complexation of mRNA to NPs enables efficient and fast cellular delivery and subsequent protein translation. While cellular uptake of both NP types was comparable, mRNA transgene expression was superior to polymer-based NPs when delivered by lipid-polymer NPs.
    • Lymphatic endothelial cells are a replicative niche for Mycobacterium tuberculosis.

      Lerner, Thomas R; de Souza Carvalho-Wodarz, Cristiane; Repnik, Urska; Russell, Matthew R G; Borel, Sophie; Diedrich, Collin R; Rohde, M; Wainwright, Helen; Collinson, Lucy M; Wilkinson, Robert J; et al. (2016-03-01)
      In extrapulmonary tuberculosis, the most common site of infection is within the lymphatic system, and there is growing recognition that lymphatic endothelial cells (LECs) are involved in immune function. Here, we identified LECs, which line the lymphatic vessels, as a niche for Mycobacterium tuberculosis in the lymph nodes of patients with tuberculosis. In cultured primary human LECs (hLECs), we determined that M. tuberculosis replicates both in the cytosol and within autophagosomes, but the bacteria failed to replicate when the virulence locus RD1 was deleted. Activation by IFN-γ induced a cell-autonomous response in hLECs via autophagy and NO production that restricted M. tuberculosis growth. Thus, depending on the activation status of LECs, autophagy can both promote and restrict replication. Together, these findings reveal a previously unrecognized role for hLECs and autophagy in tuberculosis pathogenesis and suggest that hLECs are a potential niche for M. tuberculosis that allows establishment of persistent infection in lymph nodes.
    • Macrophage uptake of cylindrical microparticles investigated with correlative microscopy.

      Tscheka, Clemens; Hittinger, Marius; Lehr, Claus-Michael; Schneider-Daum, Nicole; Schneider, Marc; Helmholtz Institute for Pharmaceutical Research Saarland (HIPS);Saarland University, Building A4.1, 66123 Saarbruecken, Germany. (2015-09)
      Cylindrical particles offer the opportunity to develop controlled and sustained release systems for the respiratory tract. One reason is that macrophages can phagocyte such particles only from either of the two ends. We investigated the uptake behaviour of murine alveolar macrophages incubated with elongated submicron-structured particles. For that purpose, fluorescent model silica nanoparticles were interconnected with the biocompatible polysaccharide agarose, building up cylindrical particles within the pores of track-etched membranes. In contrast to common approaches we determined the uptake at different time points with scanning electron microscopy, fluorescence microscopy, and the combination of both techniques - correlative microscopy (CLEM). As a consequence, we could securely identify uptake events and observe in detail the engulfment of particles and confirm, that phagocytosis could only be observed from the tips of the cylinders. CLEM allowed a comparison of the uptake measured with different techniques at identical macrophages. Qualitative and quantitative evaluation of this cylindrical particle uptake showed substantial differences between fluorescence microscopy, electron microscopy and the combination of both (CLEM) within 24h.