• Safety assessment of excipients (SAFE) for orally inhaled drug products.

      Metz, Julia K; Scharnowske, Lara; Hans, Fabian; Schnur, Sabrina; Knoth, Katharina; Zimmer, Horst; Limberger, Markus; Groß, Henrik; Lehr, Claus Michael; Hittinger, Marius; et al. (Springer, 2020-01-29)
      The development of new orally inhaled drug products requires the demonstration of safety which must be proven in animal experiments. New in vitro methods may replace, or at least reduce, these animal experiments provided they are able to correctly predict the safety or eventual toxicity in humans. However, the challenge is to link human in vitro data to human in vivo data. We here present a new approach to the safety assessment of excipients (SAFE) for pulmonary drug delivery. The SAFE model is based on a dose response curve of 23 excipients tested on the human pulmonary epithelial cell lines A549 and Calu-3. The resulting in vitro IC50 values were correlated with the FDA-approved concentration in pharmaceutical products for either pulmonary (if available) or parenteral administration. Setting a threshold of 0.1% (1 mg/mL) for either value yielded four safety classes, allowed to link IC50 data as measured on human cell cultures in vitro with the concentrations of the same compounds in FDA-approved drug products. The necessary in vitro data for novel excipients can be easily generated while the SAFE approach allows putting them in the context for eventual use in human pulmonary drug products. Excipients, that are most likely not safe for use in humans, can be early excluded from further pharmaceutical development. The SAFE approach helps thus to avoid unnecessary animal experiments.
    • Second-generation lung-on-a-chip with an array of stretchable alveoli made with a biological membrane.

      Zamprogno, Pauline; Wüthrich, Simon; Achenbach, Sven; Thoma, Giuditta; Stucki, Janick D; Hobi, Nina; Schneider-Daum, Nicole; Lehr, Claus-Michael; Huwer, Hanno; Geiser, Thomas; et al. (Nature Pulishing Group, 2021-02-05)
      The air-blood barrier with its complex architecture and dynamic environment is difficult to mimic in vitro. Lung-on-a-chips enable mimicking the breathing movements using a thin, stretchable PDMS membrane. However, they fail to reproduce the characteristic alveoli network as well as the biochemical and physical properties of the alveolar basal membrane. Here, we present a lung-on-a-chip, based on a biological, stretchable and biodegradable membrane made of collagen and elastin, that emulates an array of tiny alveoli with in vivo-like dimensions. This membrane outperforms PDMS in many ways: it does not absorb rhodamine-B, is biodegradable, is created by a simple method, and can easily be tuned to modify its thickness, composition and stiffness. The air-blood barrier is reconstituted using primary lung alveolar epithelial cells from patients and primary lung endothelial cells. Typical alveolar epithelial cell markers are expressed, while the barrier properties are preserved for up to 3 weeks.
    • Semi-automated nanoprecipitation-system--an option for operator independent, scalable and size adjustable nanoparticle synthesis.

      Rietscher, René; Thum, Carolin; Lehr, Claus-Michael; Schneider, Marc; Helmholtz Institute for Pharmaceutical Research Saarland (HIPS);Saarland University, Building A4.1, 66123 Saarbruecken, Germany. (2015-06)
      The preparation of nano-sized carrier systems increasingly moved into focus of pharmaceutical research and industry in the past decades. Besides the drug load and properties of the selected polymer/lipid, the size of such particles is one of the most important parameters regarding their use as efficient drug delivery systems. However, the preparation of nanoparticles with different sizes in a controlled manner is challenging, especially in terms of reproducibility and scale-up possibility. To overcome these hurdles we developed a system relying on nanoprecipitation, which meets all these requirements of an operator independent, scalable and size-adjustable nanoparticle synthesis-the Semi-Automated Nanoprecipitation-System. This system enables the adaption of the particle size to specific needs based on the process parameters-injection rate, flow rate and polymer concentration-identified within this study. The basic set-up is composed of a syringe pump and a gear pump for a precise control of the flow and injection speed of the system. Furthermore, a home-made tube-straightener guarantees a curvature-free injection point. Thus it could be shown that the production of poly(lactide-co-glycolide) nanoparticles from 150 to 600 nm with a narrow size distribution in a controlled semi-automatic manner is possible.
    • Setup for investigating gold nanoparticle penetration through reconstructed skin and comparison to published human skin data.

      Labouta, Hagar I; Thude, Sibylle; Schneider, Marc; Helmholtz Center for Infection Research, Helmholtz Institute for Pharmaceutical Research Saarland, Saarbrücken, Germany. (2013-06)
      Owing to the limited source of human skin (HS) and the ethical restrictions of using animals in experiments, in vitro skin equivalents are a possible alternative for conducting particle penetration experiments. The conditions for conducting penetration experiments with model particles, 15-nm gold nanoparticles (AuNP), through nonsealed skin equivalents are described for the first time. These conditions include experimental setup, sterility conditions, effective applied dose determination, skin sectioning, and skin integrity check. Penetration at different exposure times (two and 24 h) and after tissue fixation (fixed versus unfixed skin) are examined to establish a benchmark in comparison to HS in an attempt to get similar results to HS experiments presented earlier. Multiphoton microscopy is used to detect gold luminescence in skin sections. λ(ex)=800 nm is used for excitation of AuNP and skin samples, allowing us to determine a relative index for particle penetration. Despite the observed overpredictability of penetration into skin equivalents, they could serve as a first fast screen for testing the behavior of nanoparticles and extrapolate their penetration behavior into HS. Further investigations are required to test a wide range of particles of different physicochemical properties to validate the skin equivalent-human skin particle penetration relationship.
    • Solid Phase Extraction as an Innovative Separation Method for Measuring Free and Entrapped Drug in Lipid Nanoparticles.

      Guillot, Alexis; Couffin, Anne-Claude; Sejean, Xavier; Navarro, Fabrice; Limberger, Markus; Lehr, Claus-Michael; Helmholtz Institute for Pharmaceutical Research Saarland (HIPS);Saarland University, Building A4.1, 66123 Saarbruecken, Germany. (2015-12)
      Contrary to physical characterization techniques for nanopharmaceuticals (shape, size and zeta-potential), the techniques to quantify the free and the entrapped drug remain very few and difficult to transpose in routine analytical laboratories. The application of Solid Phase Extraction (SPE) technique was investigated to overcome this challenge.
    • Spray-dried lactose-leucine microparticles for pulmonary delivery of antimycobacterial nanopharmaceuticals.

      Thiyagarajan, Durairaj; Huck, Benedikt; Nothdurft, Birgit; Koch, Marcus; Rudolph, David; Rutschmann, Mark; Feldmann, Claus; Hozsa, Constantin; Furch, Marcus; Besecke, Karen F W; et al. (2021-06-08)
    • Squalenyl Hydrogen Sulfate Nanoparticles for Simultaneous Delivery of Tobramycin and an Alkylquinolone Quorum Sensing Inhibitor Enable the Eradication of P. aeruginosa Biofilm Infections.

      Ho, Duy-Khiet; Murgia, Xabier; de Rossi, Chiara; Christmann, Rebekka; Hüfner de Mello Martins, Antonio G; Koch, Marcus; Andreas, Anastasia; Herrmann, Jennifer; Müller, Rolf; Empting, Martin; et al. (Wiley, 2020-04-03)
      Elimination of pulmonary Pseudomonas aeruginosa (PA) infections is challenging to accomplish with antibiotic therapies, mainly due to resistance mechanisms. Quorum sensing inhibitors (QSIs) interfering with biofilm formation can thus complement antibiotics. For simultaneous and improved delivery of both active agents to the infection sites, self-assembling nanoparticles of a newly synthesized squalenyl hydrogen sulfate (SqNPs) were prepared. These nanocarriers allowed for remarkably high loading capacities of hydrophilic antibiotic tobramycin (Tob) and a novel lipophilic QSI at 30 % and circa 10 %, respectively. The drug-loaded SqNPs showed improved biofilm penetration and enhanced efficacy in relevant biological barriers (mucin/human tracheal mucus, biofilm), leading to complete eradication of PA biofilms at circa 16-fold lower Tob concentration than Tob alone. This study offers a viable therapy optimization and invigorates the research and development of QSIs for clinical use.
    • Starch-Chitosan Polyplexes: A Versatile Carrier System for Anti-Infectives and Gene Delivery

      Yasar, Hanzey; Ho, Duy-Khiet; De Rossi, Chiara; Herrmann, Jennifer; Gordon, Sarah; Loretz, Brigitta; Lehr, Claus Michael; HIPS, Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus 8.1, 66123 Saarbrücken, Germany. (2018-03-01)
    • A strategy for in-silico prediction of skin absorption in man.

      Selzer, Dominik; Neumann, Dirk; Neumann, Heike; Kostka, Karl-Heinz; Lehr, Claus-Michael; Schaefer, Ulrich F; Helmholtz Institute for Pharmaceutical Research Saarland (HIPS);Saarland University, Building A4.1, 66123 Saarbruecken, Germany. (2015-09)
      For some time, in-silico models to address substance transport into and through the skin are gaining more and more importance in different fields of science and industry. In particular, the mathematical prediction of in-vivo skin absorption is of great interest to overcome ethical and economical issues. The presented work outlines a strategy to address this problem and in particular, investigates in-vitro and in-vivo skin penetration experiments of the model compound flufenamic acid solved in an ointment by means of a mathematical model. Experimental stratum corneum concentration-depth profiles (SC-CDP) for various time intervals using two different in-vitro systems (Franz diffusion cell, Saarbruecken penetration model) were examined and simulated with the help of a highly optimized three compartment numerical diffusion model and compared to the findings of SC-CDPs of the in-vivo scenario. Fitted model input parameters (diffusion coefficient and partition coefficient with respect to the stratum corneum) for the in-vitro infinite dose case could be used to predict the in-use conditions in-vitro. Despite apparent differences in calculated partition coefficients between in-vivo and in-vitro studies, prediction of in-vivo scenarios from input parameters calculated from the in-vitro case yielded reasonable results.
    • Surface-modified yeast cells: A novel eukaryotic carrier for oral application.

      Kenngott, Elisabeth E; Kiefer, Ruth; Schneider-Daum, Nicole; Hamann, Alf; Schneider, Marc; Schmitt, Manfred J; Breinig, Frank; Helmholtz Institute for Pharmaceutical Research Saarland (HIPS);Saarland University, Building A4.1, 66123 Saarbruecken, Germany. (2016-02-28)
      The effective targeting and subsequent binding of particulate carriers to M cells in Peyer's patches of the gut is a prerequisite for the development of oral delivery systems. We have established a novel carrier system based on cell surface expression of the β1-integrin binding domain of invasins derived from Yersinia enterocolitica and Yersinia pseudotuberculosis on the yeast Saccharomyces cerevisiae. All invasin derivatives were shown to be effectively expressed on the cell surface and recombinant yeast cells showed improved binding to both human HEp-2 cells and M-like cells in vitro. Among the different derivatives tested, the integrin-binding domain of Y. enterocolitica invasin proved to be the most effective and was able to target Peyer's patches in vivo. In conclusion, cell surface-modified yeasts might provide a novel bioadhesive, eukaryotic carrier system for efficient and targeted delivery of either antigens or drugs via the oral route.
    • Surfactant replacement therapy in combination with different non-invasive ventilation techniques in spontaneously-breathing, surfactant-depleted adult rabbits.

      Ricci, Francesca; Casiraghi, Costanza; Storti, Matteo; D'Alò, Francesco; Catozzi, Chiara; Ciccimarra, Roberta; Ravanetti, Francesca; Cacchioli, Antonio; Villetti, Gino; Civelli, Maurizio; et al. (2018-01-01)
      Nasal intermittent positive pressure ventilation (NIPPV) holds great potential as a primary ventilation support method for Respiratory Distress Syndrome (RDS). The use of NIPPV may also be of great value combined with minimally invasive surfactant delivery. Our aim was to implement an in vivo model of RDS, which can be managed with different non-invasive ventilation (NIV) strategies, including non-synchronized NIPPV, synchronized NIPPV (SNIPPV), and nasal continuous positive airway pressure (NCPAP). Forty-two surfactant-depleted adult rabbits were allocated in six different groups: three groups of animals were treated with only NIV for three hours (NIPPV, SNIPPV, and NCPAP groups), while three other groups were treated with surfactant (SF) followed by NIV (NIPPV+SF, SNIPPV+SF, and NCPAP+SF groups). Arterial gas exchange, ventilation indices, and dynamic compliance were assessed. Post-mortem the lungs were sampled for histological evaluation. Surfactant depletion was successfully achieved by repeated broncho-alveolar lavages (BALs). After BALs, all animals developed a moderate respiratory distress, which could not be reverted by merely applying NIV. Conversely, surfactant administration followed by NIV induced a rapid improvement of arterial oxygenation in all surfactant-treated groups. Breath synchronization was associated with a significantly better response in terms of gas exchange and dynamic compliance compared to non-synchronized NIPPV, showing also the lowest injury scores after histological assessment. The proposed in vivo model of surfactant deficiency was successfully managed with NCPAP, NIPPV, or SNIPPV; this model resembles a moderate respiratory distress and it is suitable for the preclinical testing of less invasive surfactant administration techniques.
    • The synergistic effect of chlorotoxin-mApoE in boosting drug-loaded liposomes across the BBB.

      Formicola, Beatrice; Dal Magro, Roberta; Montefusco-Pereira, Carlos V; Lehr, Claus-Michael; Koch, Marcus; Russo, Laura; Grasso, Gianvito; Deriu, Marco A; Danani, Andrea; Bourdoulous, Sandrine; et al. (BMC, 2019-11-11)
      We designed liposomes dually functionalized with ApoE-derived peptide (mApoE) and chlorotoxin (ClTx) to improve their blood-brain barrier (BBB) crossing. Our results demonstrated the synergistic activity of ClTx-mApoE in boosting doxorubicin-loaded liposomes across the BBB, keeping the anti-tumour activity of the drug loaded: mApoE acts promoting cellular uptake, while ClTx promotes exocytosis of liposomes.
    • Synthesis and Biopharmaceutical Characterization of Amphiphilic Squalenyl Derivative Based Versatile Drug Delivery Platform.

      Ho, Duy-Khiet; Christmann, Rebekka; Murgia, Xabier; de Rossi, Chiara; Frisch, Sarah; Koch, Marcus; Schaefer, Ulrich F; Loretz, Brigitta; Desmaele, Didier; Couvreur, Patrick; et al. (Frontiers, 2020-10-19)
      Hepatitis C virus (HCV) has no animal reservoir, infecting only humans. To investigate species barrier determinants limiting infection of rodents, murine liver complementary DNA library screening was performed, identifying transmembrane proteins Cd302 and Cr1l as potent restrictors of HCV propagation. Combined ectopic expression in human hepatoma cells impeded HCV uptake and cooperatively mediated transcriptional dysregulation of a noncanonical program of immunity genes. Murine hepatocyte expression of both factors was constitutive and not interferon inducible, while differences in liver expression and the ability to restrict HCV were observed between the murine orthologs and their human counterparts. Genetic ablation of endogenous Cd302 expression in human HCV entry factor transgenic mice increased hepatocyte permissiveness for an adapted HCV strain and dysregulated expression of metabolic process and host defense genes. These findings highlight human-mouse differences in liver-intrinsic antiviral immunity and facilitate the development of next-generation murine models for preclinical testing of HCV vaccine candidates.
    • Synthesis and characterization of human transferrin-stabilized gold nanoclusters.

      Le Guével, Xavier; Daum, Nicole; Schneider, Marc; Pharmaceutical Nanotechnology, Saarland University, Saarbrücken, Germany. (2011-07-08)
      Human transferrin has been biolabelled with gold nanoclusters (Au NCs) using a simple, fast and non-toxic method. These nanocrystals (<2 nm) are stabilized in the protein via sulfur groups and have a high fluorescence emission in the near infrared region (QY=4.3%; λem=695 nm). Structural investigation and photophysical measurements show a high population of clusters formed of 22-33 gold atoms covalently bound to the transferrin. In solutions with pH ranging from 5 to 10 and in buffer solutions (PBS, HEPES), those biolabelled proteins exhibit a good stability. No significant quenching effect of the fluorescent transferrin has been detected after iron loading of iron-free transferrin (apoTf) and in the presence of a specific polyclonal antibody. Additionally, antibody-induced agglomeration demonstrates no alteration in the protein activity and the receptor target ability. MTT and Vialight® Plus tests show no cytotoxicity of these labelled proteins in cells (1 µg ml(-1)-1 mg ml(-1)). Cell line experiments (A549) indicate also an uptake of the iron loaded fluorescent proteins inside cells. These remarkable data highlight the potential of a new type of non-toxic fluorescent transferrin for imaging and targeting.
    • Synthesis of a deuterated probe for the confocal Raman microscopy imaging of squalenoyl nanomedicines

      Buchy, Eric; Vukosavljevic, Branko; Windbergs, Maike; Sobot, Dunja; Dejean, Camille; Mura, Simona; Couvreur, Patrick; Desmaële, Didier; Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1,56123 Saarbrücken, Germany. (2016-06-06)
    • Telomerase as an emerging target to fight cancer--opportunities and challenges for nanomedicine.

      Philippi, C; Loretz, B; Schaefer, U F; Lehr, C M; Department of Biopharmaceutics and Pharmaceutical Technology, Saarland University, Saarbrücken, Germany. (2010-09-01)
      Telomerase as an enzyme is responsible for the renewal of the chromosomal ends, the so-called telomeres. By preventing them from shortening with each cell cycle, telomerase is able to inhibit cellular senescence and apoptosis. Telomerase activity, which is detectable in the majority of cancer cells, allows them to maintain their proliferative capacity. The thus obtained immortality of those cells again is a key to their malignancy. Based on these discoveries, it is obvious that telomerase inhibitors would represent an innovative approach to fight cancer, and a variety of such candidate molecules are currently in the pipeline. Telomerase inhibitors largely fall in two classes of compounds: small synthetic molecules and nucleotide-based biologicals. For several candidates, some proof of concept studies have been demonstrated, either on cell cultures or in animal models. But the same studies also revealed that inefficient delivery is largely limiting the translational step into the clinic. The most appealing feature of telomerase inhibitors, which distinguishes them from conventional anticancer drugs, is probably seen in their intrinsic non-toxicity to normal cells. Nevertheless, efficient delivery to the target cells, i.e. to the tumor, is still required. Here, some well-known biopharmaceutical problems such as insufficient solubility, permeability or even metabolic stability are frequently encountered. To address these challenges, there is a clear need for adequate delivery technologies, for example by using nanomedicines, that would allow to overcome their biopharmaceutical shortcomings and to warrant a sufficient bioavailability at the target side. This review first briefly explains the concept of telomerase and telomerase inhibition in cancer therapy. It secondly aims to provide an overview of the different currently known telomerase inhibitors. Finally, the biopharmaceutical limitations of these molecules are discussed as well as the possibilities to overcome those limits by novel drug carrier systems and formulation approaches.
    • Three-dimensional hierarchical cultivation of human skin cells on bio-adaptive hybrid fibers.

      Planz, Viktoria; Seif, Salem; Atchison, Jennifer S; Vukosavljevic, Branko; Sparenberg, Lisa; Kroner, Elmar; Windbergs, Maike; Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS),Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany. (2016-07-11)
      The human skin comprises a complex multi-scale layered structure with hierarchical organization of different cells within the extracellular matrix (ECM). This supportive fiber-reinforced structure provides a dynamically changing microenvironment with specific topographical, mechanical and biochemical cell recognition sites to facilitate cell attachment and proliferation. Current advances in developing artificial matrices for cultivation of human cells concentrate on surface functionalizing of biocompatible materials with different biomolecules like growth factors to enhance cell attachment. However, an often neglected aspect for efficient modulation of cell-matrix interactions is posed by the mechanical characteristics of such artificial matrices. To address this issue, we fabricated biocompatible hybrid fibers simulating the complex biomechanical characteristics of native ECM in human skin. Subsequently, we analyzed interactions of such fibers with human skin cells focusing on the identification of key fiber characteristics for optimized cell-matrix interactions. We successfully identified the mediating effect of bio-adaptive elasto-plastic stiffness paired with hydrophilic surface properties as key factors for cell attachment and proliferation, thus elucidating the synergistic role of these parameters to induce cellular responses. Co-cultivation of fibroblasts and keratinocytes on such fiber mats representing the specific cells in dermis and epidermis resulted in a hierarchical organization of dermal and epidermal tissue layers. In addition, terminal differentiation of keratinocytes at the air interface was observed. These findings provide valuable new insights into cell behaviour in three-dimensional structures and cell-material interactions which can be used for rational development of bio-inspired functional materials for advanced biomedical applications.
    • Tobacco Smoke and Inhaled Drugs Alter Expression and Activity of Multidrug Resistance-Associated Protein-1 (MRP1) in Human Distal Lung Epithelial Cells .

      Selo, Mohammed Ali; Delmas, Anne-Sophie; Springer, Lisa; Zoufal, Viktoria; Sake, Johannes A; Clerkin, Caoimhe G; Huwer, Hanno; Schneider-Daum, Nicole; Lehr, Claus-Michael; Nickel, Sabrina; et al. (Frontiers, 2020-09-08)
      Multidrug resistance-associated protein-1 (MRP1/ABCC1) is highly expressed in human lung tissues. Recent studies suggest that it significantly affects the pulmonary disposition of its substrates, both after pulmonary and systemic administration. To better understand the molecular mechanisms involved, we studied the expression, subcellular localization and activity of MRP1 in freshly isolated human alveolar epithelial type 2 (AT2) and type 1-like (AT1-like) cells in primary culture, and in the NCI-H441 cell line. Moreover, the effect of cigarette smoke extract (CSE) and a series of inhaled drugs on MRP1 abundance and activity was investigated in vitro. MRP1 expression levels were measured by q-PCR and immunoblot in AT2 and AT1-like cells from different donors and in several passages of the NCI-H441 cell line. The subcellular localization of the transporter was studied by confocal laser scanning microscopy and cell surface protein biotinylation. MRP1 activity was assessed by bidirectional transport and efflux experiments using the MRP1 substrate, 5(6)-carboxyfluorescein [CF; formed intracellularly from 5(6)-carboxyfluorescein-diacetate (CFDA)] in AT1-like and NCI-H441 cell monolayers. Furthermore, the effect of CSE as well as several bronchodilators and inhaled corticosteroids on MRP1 abundance and CF efflux was investigated. MRP1 protein abundance increased upon differentiation from AT2 to AT1-like phenotype, however, ABCC1 gene levels remained unchanged. MRP1 abundance in NCI-H441 cells were comparable to those found in AT1-like cells. The transporter was detected primarily in basolateral membranes of both cell types which was consistent with net basolateral efflux of CF. Likewise, bidirectional transport studies showed net apical-to-basolateral transport of CF which was sensitive to the MRP1 inhibitor MK-571. Budesonide, beclomethasone dipropionate, salbutamol sulfate, and CSE decreased CF efflux in a concentration-dependent manner. Interestingly, CSE increased MRP1 abundance, whereas budesonide, beclomethasone dipropionate, salbutamol sulfate did not have such effect. CSE and inhaled drugs can reduce MRP1 activity in vitro, which implies the transporter being a potential drug target in the treatment of chronic obstructive pulmonary disease (COPD). Moreover, MRP1 expression level, localization and activity were comparable in human AT1-like and NCI-H441 cells. Therefore, the cell line can be a useful alternative in vitro model to study MRP1 in distal lung epithelium.
    • Tobramycin Liquid Crystal Nanoparticles Eradicate Cystic Fibrosis-Related Pseudomonas aeruginosa Biofilms.

      Thorn, Chelsea R; Carvalho-Wodarz, Cristiane de Souza; Horstmann, Justus C; Lehr, Claus-Michael; Prestidge, Clive A; Thomas, Nicky; HIPS, Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany. (Wiley-VCH, 2021-05-12)
      Pseudomonas aeruginosa biofilms cause persistent and chronic infections, most known clinically in cystic fibrosis (CF). Tobramycin (TOB) is a standard anti-pseudomonal antibiotic; however, in biofilm infections, its efficacy severely decreases due to limited permeability across the biofilm matrix. Herewith, a biomimetic, nanostructured, lipid liquid crystal nanoparticle-(LCNP)-formulation is discovered to significantly enhance the efficacy of TOB and eradicate P. aeruginosa biofilm infections. Using an advanced, biologically-relevant co-culture model of human CF bronchial epithelial cells infected with P. aeruginosa biofilms at an air-liquid interface, nebulized TOB-LCNPs completely eradicated 1 × 109 CFU mL-1 of P. aeruginosa after two doses, a 100-fold improvement over the unformulated antibiotic. The enhanced activity of TOB is not observed with a liposomal formulation of TOB or with ciprofloxacin, an antibiotic that readily penetrates biofilms. It is demonstrated that the unique nanostructure of the LCNPs drives the enhanced penetration of TOB across the biofilm barrier, but not through the healthy lung epithelium barrier, significantly increasing the available antibiotic concentration at the site of infection. The LCNPs are an innovative strategy to improve the performance of TOB as a directed pulmonary therapy, enabling the administration of lower doses, reducing the toxicity, and amplifying the anti-biofilm activity of the anti-pseudomonal antibiotic.
    • Tofacitinib Loaded Squalenyl Nanoparticles for Targeted Follicular Delivery in Inflammatory Skin Diseases.

      Christmann, Rebekka; Ho, Duy-Khiet; Wilzopolski, Jenny; Lee, Sangeun; Koch, Marcus; Loretz, Brigitta; Vogt, Thomas; Bäumer, Wolfgang; Schaefer, Ulrich F; Lehr, Claus-Michael; et al. (MDPI, 2020-11-24)
      Tofacitinib (TFB), a Janus kinase inhibitor, has shown excellent success off-label in treating various dermatological diseases, especially alopecia areata (AA). However, TFB's safe and targeted delivery into hair follicles (HFs) is highly desirable due to its systemic adverse effects. Nanoparticles (NPs) can enhance targeted follicular drug delivery and minimize interfollicular permeation and thereby reduce systemic drug exposure. In this study, we report a facile method to assemble the stable and uniform 240 nm TFB loaded squalenyl derivative (SqD) nanoparticles (TFB SqD NPs) in aqueous solution, which allowed an excellent loading capacity (LC) of 20%. The SqD NPs showed an enhanced TFB delivery into HFs compared to the aqueous formulations of plain drug in an ex vivo pig ear model. Furthermore, the therapeutic efficacy of the TFB SqD NPs was studied in a mouse model of allergic dermatitis by ear swelling reduction and compared to TFB dissolved in a non-aqueous mixture of acetone and DMSO (7:1 v/v). Whereas such formulation would not be acceptable for use in the clinic, the TFB SqD NPs dispersed in water illustrated a better reduction in inflammatory effects than plain TFB's aqueous formulation, implying both encouraging good in vivo efficacy and safety. These findings support the potential of TFB SqD NPs for developing a long-term topical therapy of AA.