15 results on '"Lisa Gamrad"'
Search Results
2. Tailored protein encapsulation into a DNA host using geometrically organized supramolecular interactions
- Author
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Andreas Sprengel, Pascal Lill, Pierre Stegemann, Kenny Bravo-Rodriguez, Elisa-C. Schöneweiß, Melisa Merdanovic, Daniel Gudnason, Mikayel Aznauryan, Lisa Gamrad, Stephan Barcikowski, Elsa Sanchez-Garcia, Victoria Birkedal, Christos Gatsogiannis, Michael Ehrmann, and Barbara Saccà
- Subjects
Science - Abstract
Current strategies for protein encapsulation in DNA vessels for controlled enzymatic catalysis or therapeutic delivery rely on formation of covalent complexes. Here, the authors design a system that mimics natural reversible non-covalent host–guest interactions between a DNA host and the protein DegP.
- Published
- 2017
- Full Text
- View/download PDF
3. Current state of laser synthesis of metal and alloy nanoparticles as ligand-free reference materials for nano-toxicological assays
- Author
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Christoph Rehbock, Jurij Jakobi, Lisa Gamrad, Selina van der Meer, Daniela Tiedemann, Ulrike Taylor, Wilfried Kues, Detlef Rath, and Stephan Barcikowski
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albumin ,gold-silver ,implant alloy ,laser ablation ,nickel-titanium ,size control ,wear debris ,Technology ,Chemical technology ,TP1-1185 ,Science ,Physics ,QC1-999 - Abstract
Due to the abundance of nanomaterials in medical devices and everyday products, toxicological effects related to nanoparticles released from these materials, e.g., by mechanical wear, are a growing matter of concern. Unfortunately, appropriate nanoparticles required for systematic toxicological evaluation of these materials are still lacking. Here, the ubiquitous presence of surface ligands, remaining from chemical synthesis are a major drawback as these organic residues may cause cross-contaminations in toxicological studies. Nanoparticles synthesized by pulsed laser ablation in liquid are a promising alternative as this synthesis route provides totally ligand-free nanoparticles. The first part of this article reviews recent methods that allow the size control of laser-fabricated nanoparticles, focusing on laser post irradiation, delayed bioconjugation and in situ size quenching by low salinity electrolytes. Subsequent or parallel applications of these methods enable precise tuning of the particle diameters in a regime from 4–400 nm without utilization of any artificial surface ligands. The second paragraph of this article highlights the recent progress concerning the synthesis of composition controlled alloy nanoparticles by laser ablation in liquids. Here, binary and ternary alloy nanoparticles with totally homogeneous elemental distribution could be fabricated and the composition of these particles closely resembled bulk implant material. Finally, the model AuAg was used to systematically evaluate composition related toxicological effects of alloy nanoparticles. Here Ag+ ion release is identified as the most probable mechanism of toxicity when recent toxicological studies with gametes, mammalian cells and bacteria are considered.
- Published
- 2014
- Full Text
- View/download PDF
4. Injection of ligand-free gold and silver nanoparticles into murine embryos does not impact pre-implantation development
- Author
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Ulrike Taylor, Wiebke Garrels, Annette Barchanski, Svea Peterson, Laszlo Sajti, Andrea Lucas-Hahn, Lisa Gamrad, Ulrich Baulain, Sabine Klein, Wilfried A. Kues, Stephan Barcikowski, and Detlef Rath
- Subjects
biomedical application ,confocal microscopy ,gene expression ,protein corona ,toxicity ,Technology ,Chemical technology ,TP1-1185 ,Science ,Physics ,QC1-999 - Abstract
Intended exposure to gold and silver nanoparticles has increased exponentially over the last decade and will continue to rise due to their use in biomedical applications. In particular, reprotoxicological aspects of these particles still need to be addressed so that the potential impacts of this development on human health can be reliably estimated. Therefore, in this study the toxicity of gold and silver nanoparticles on mammalian preimplantation development was assessed by injecting nanoparticles into one blastomere of murine 2 cell-embryos, while the sister blastomere served as an internal control. After treatment, embryos were cultured and embryo development up to the blastocyst stage was assessed. Development rates did not differ between microinjected and control groups (gold nanoparticles: 67.3%, silver nanoparticles: 61.5%, sham: 66.2%, handling control: 79.4%). Real-time PCR analysis of six developmentally important genes (BAX, BCL2L2, TP53, OCT4, NANOG, DNMT3A) did not reveal an influence on gene expression in blastocysts. Contrary to silver nanoparticles, exposure to comparable Ag+-ion concentrations resulted in an immediate arrest of embryo development. In conclusion, the results do not indicate any detrimental effect of colloidal gold or silver nanoparticles on the development of murine embryos.
- Published
- 2014
- Full Text
- View/download PDF
5. Impact of diesel exhaust exposure on urinary 1-hydroxypyrene in underground salt and potash workers
- Author
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Swaantje Casjens, Savo Neumann, Katrin Rühle, Lisa Gamrad-Streubel, Lisa-Marie Haase, Katharina K. Rudolph, Thomas Birk, Jörg Giesen, Volker Neumann, Dirk Pallapies, Jürgen Bünger, Heiko U. Käfferlein, Thomas Behrens, Thomas Brüning, and Dirk Taeger
- Subjects
Public Health, Environmental and Occupational Health - Published
- 2023
6. Underground salt and potash workers exposed to nitrogen oxides and diesel exhaust: assessment of specific effect biomarkers
- Author
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Lisa Gamrad-Streubel, Lisa-Marie Haase, Katharina K. Rudolph, Katrin Rühle, Annette M. Bachand, Lori Crawford, Kenneth A. Mundt, Jürgen Bünger, Dirk Pallapies, Dirk Taeger, Swaantje Casjens, Anja Molkenthin, Savo Neumann, Jörg Giesen, Volker Neumann, Thomas Brüning, and Thomas Birk
- Subjects
Cross-Sectional Studies ,Occupational Exposure ,Nitrogen Dioxide ,Public Health, Environmental and Occupational Health ,Humans ,Nitrogen Oxides ,Air Pollutants, Occupational ,Biomarkers ,Vehicle Emissions ,Environmental Monitoring - Abstract
Purpose Occupational exposure limits (OEL) for nitrogen oxides (NO, NO2) and diesel exhaust (EC-DPM) were reassessed by the German authorities in 2016/2017. We performed a clinical cross-sectional study among salt and potash underground workers exposed to these substances at relatively high levels to examine possible indicators of acute effects on workers’ health. Methods We measured post- versus pre-shift differences in cardiovascular, inflammatory, immune, and respiratory effect biomarkers and assessed their associations with personal exposures measured during the same shift. We also compared post- versus pre-shift differences in biomarker levels between exposure groups defined based on work site and job type. Results None of the above-ground workers exceeded the OEL for NO2 and only 5% exceeded the OEL for EC-DPM exposure. Among underground workers, 33% of miners and 7% underground maintenance workers exceeded the OEL for NO2; the OEL for EC-DPM was exceeded by 56% of miners and 17% of maintenance workers. Some effect biomarkers (thrombocytes, neutrophils, MPO, TNF-α, IgE, FeNO) showed statistically significant differences between pre- versus post-shift measurements; however, there were no consistent associations between pre- and post-shift differences and exposure group or personal exposure measurements during the shift. Conclusions We did not find evidence of associations between workplace exposure to NO, NO2 or EC-DPM and clinically relevant indicators of acute cardiovascular, inflammatory and immune, or respiratory effects among salt and potash underground workers in Germany.
- Published
- 2022
7. Laser-based in situ embedding of metal nanoparticles into bioextruded alginate hydrogel tubes enhances human endothelial cell adhesion
- Author
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Lisa Gamrad, Marius Köpf, Christoph Rehbock, Bernd Sures, Nina Million, Horst Fischer, Daniela F. Duarte Campos, Andreas Blaeser, Milen Nachev, and Stephan Barcikowski
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Nanocomposite ,Materials science ,Chemie ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,Adhesion ,Physik (inkl. Astronomie) ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Endothelial stem cell ,Tissue engineering ,Self-healing hydrogels ,Biophysics ,General Materials Science ,Electrical and Electronic Engineering ,0210 nano-technology ,Cell adhesion ,Biofabrication - Abstract
Alginate is a widely used hydrogel in tissue engineering owing to its simple and non-cytotoxic gelation process, ease of use, and abundance. However, unlike hydrogels derived from mammalian sources such as collagen, alginate does not contain cell adhesion ligands. Here, we present a novel laser ablation technique for the in situ embedding of gold and iron nanoparticles into hydrogels. We hypothesized that integration of metal nanoparticles in alginate could serve as an alternative material because of its chemical biofunctionalization ability (coupling of RGD ligands) to favor cell adhesion. Cytocompatibility and biofunctionality of the gels were assessed by cell culture experiments using fibroblasts and endothelial cells. Nanoparticles with an average particle size of 3 nm (gold) and 6 nm (iron) were generated and stably maintained in alginate for up to 6 months. Using an extrusion system, several centimeter-long alginate tubes with an outer diameter of approximately 3 mm and a wall thickness of approximately 150 μm were manufactured. Confocal microscopy revealed homogeneously distributed nanoparticle agglomerates over the entire tube volume. Endothelial cells seeded on iron-loaded gels showed significantly higher viability and an increased degree of spreading, and the number of attached cells was also elevated in comparison to the control and gold-loaded alginates. We conclude that laser-based in situ integration of iron nanoparticles (⩽0.01 wt.%) in alginate is a straightforward method to generate composite materials that favor the adhesion of endothelial cells. In addition, we show that nanoparticle integration does not impair the alginate’s gelation and 3D biofabrication properties.
- Published
- 2016
8. Bioconjugated Gold Nanoparticles Penetrate Into Spermatozoa Depending on Plasma Membrane Status
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Detlef Rath, Stephan Barcikowski, Lisa Gamrad, Csaba László Sajti, Ulrike Taylor, Annette Barchanski, and Wilfried A. Kues
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Male ,Cell Membrane Permeability ,Surface Properties ,media_common.quotation_subject ,Acrosome reaction ,Chemie ,Oligonucleotides ,Biomedical Engineering ,Metal Nanoparticles ,Pharmaceutical Science ,Medicine (miscellaneous) ,Bioengineering ,Peptide ,Nanoconjugates ,Biology ,Transfection ,Bivalent (genetics) ,Diffusion ,Cell membrane ,Materials Testing ,medicine ,Animals ,General Materials Science ,Particle Size ,Internalization ,Cells, Cultured ,media_common ,chemistry.chemical_classification ,Oligonucleotide ,Cell Membrane ,Spermatozoa ,Molecular biology ,Membrane ,medicine.anatomical_structure ,chemistry ,Colloidal gold ,Biophysics ,Cattle ,Gold - Abstract
Spermatozoa are not only essential for animal reproduction they also represent important tools for the manipulation of animal genetics. For instance, the genetic labeling and analysis of spermatozoa could provide a prospective complementation of pre-fertilization diagnosis and could help to prevent the inheritance of defective alleles during artificial insemination or to select beneficial traits in livestock. Spermatozoa feature extremely specialized membrane organization and restricted transport mechanisms making the labeling of genetically interesting DNA-sequences, e.g., with gold nanoparticles, a particular challenge. Here, we present a systematic study on the size-related internalization of ligand-free, monovalent and bivalent polydisperse gold nanoparticles, depending on spermatozoa membrane status. While monovalent conjugates were coupled solely to either negatively-charged oligonucleotides or positively-charged cell-penetrating peptides, bivalent conjugates were functionalized with both molecules simultaneously. The results clearly indicate that the cell membrane of acrosome-intact, bovine spermatozoa was neither permeable to ligand-free or oligonucleotide-conjugated nanoparticles, nor responsive to the mechanisms of cell-penetrating peptides. Interestingly, after acrosome reaction, which comprises major changes in sperm membrane composition, fluidity and charge, high numbers of monovalent and bivalent nanoparticles were found in the postequatorial segment, depicting a close and complex correlation between particle internalization and membrane organization. Additionally, depending on the applied peptide and for nanoparticle sizes < 10 nm even a successive nuclear penetration was observed, making the bivalent conjugates promising for future genetic delivery and sorting issues.
- Published
- 2015
9. Tailored protein encapsulation into a DNA host using geometrically organized supramolecular interactions
- Author
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Michael Ehrmann, Daniel Gudnason, Lisa Gamrad, Elisa-Charlott Schöneweiß, Stephan Barcikowski, Melisa Merdanovic, Kenny Bravo-Rodriguez, Barbara Saccà, Pascal Lill, Andreas Sprengel, Victoria Birkedal, Christos Gatsogiannis, Elsa Sanchez-Garcia, Pierre Stegemann, and Mikayel Aznauryan
- Subjects
Models, Molecular ,0301 basic medicine ,Polymers ,Science ,Forschungszentren » Zentrum für Medizinische Biotechnologie (ZMB) ,Supramolecular chemistry ,Chemie ,General Physics and Astronomy ,Nanotechnology ,Chemistry Techniques, Synthetic ,macromolecular substances ,Ligands ,010402 general chemistry ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,chemistry.chemical_compound ,Forschungszentren » Center for Nanointegration Duisburg-Essen (CENIDE) ,Molecular recognition ,ddc:570 ,Molecule ,Protein Interaction Domains and Motifs ,A-DNA ,Binding site ,Heat-Shock Proteins ,Binding Sites ,Multidisciplinary ,Molecular Structure ,Serine Endopeptidases ,Intermolecular force ,DNA ,General Chemistry ,Molecular Imaging ,0104 chemical sciences ,030104 developmental biology ,chemistry ,Molecular Probes ,Periplasmic Proteins ,Genetic Engineering ,Molecular probe ,Biologie - Abstract
The self-organizational properties of DNA have been used to realize synthetic hosts for protein encapsulation. However, current strategies of DNA–protein conjugation still limit true emulation of natural host–guest systems, whose formation relies on non-covalent bonds between geometrically matching interfaces. Here we report one of the largest DNA–protein complexes of semisynthetic origin held in place exclusively by spatially defined supramolecular interactions. Our approach is based on the decoration of the inner surface of a DNA origami hollow structure with multiple ligands converging to their corresponding binding sites on the protein surface with programmable symmetry and range-of-action. Our results demonstrate specific host–guest recognition in a 1:1 stoichiometry and selectivity for the guest whose size guarantees sufficient molecular diffusion preserving short intermolecular distances. DNA nanocontainers can be thus rationally designed to trap single guest molecules in their native form, mimicking natural strategies of molecular recognition and anticipating a new method of protein caging., Current strategies for protein encapsulation in DNA vessels for controlled enzymatic catalysis or therapeutic delivery rely on formation of covalent complexes. Here, the authors design a system that mimics natural reversible non-covalent host–guest interactions between a DNA host and the protein DegP.
- Published
- 2017
10. Charge Balancing of Model Gold-Nanoparticle-Peptide Conjugates Controlled by the Peptide’s Net Charge and the Ligand to Nanoparticle Ratio
- Author
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Christoph Rehbock, Stephan Barcikowski, Lisa Gamrad, Alexander Heisterkamp, B. Tumursukh, and Judith Krawinkel
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chemistry.chemical_classification ,Bioconjugation ,Biomolecule ,Chemie ,Nanoparticle ,Nanotechnology ,Peptide ,Conjugated system ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,General Energy ,Isoelectric point ,chemistry ,Covalent bond ,Colloidal gold ,Biophysics ,Physical and Theoretical Chemistry - Abstract
Gold nanoparticles (AuNPs) covalently bound to biomolecules, termed bioconjugates,1 are highly relevant for biological applications like drug targeting or bioimaging. Here, the net charge of the bioconjugate is one key parameter affecting biocompatibility and cell membrane interaction. However, when negatively charged AuNPs are conjugated to positively charged biomolecules, resulting charge compensation compromises the stability of the conjugates. In this work, laser-generated negatively charged AuNPs exhibiting a bare surface were used as a model and separately conjugated to cell penetrating peptides (CPPs) carrying different positive net charges. Occurring charge compensation leads to two regimes where stable bioconjugates are obtained on both sides of the bioconjugate’s isoelectric point. These regimes can be controlled by the peptide’s net charge. Generally, increasing the peptide’s net charges yields stable positively charged bioconjugates with decreased surface coverages. To demonstrate the compatib...
- Published
- 2014
11. Size control of laser-fabricated surfactant-free gold nanoparticles with highly diluted electrolytes and their subsequent bioconjugation
- Author
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Lisa Gamrad, Vivian Merk, Christoph Rehbock, René Streubel, and Stephan Barcikowski
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Dispersity ,Chemie ,Metal Nanoparticles ,General Physics and Astronomy ,Ionic bonding ,Nanoparticle ,Nanotechnology ,Electrolyte ,Electrolytes ,Surface-Active Agents ,Drug Stability ,Animals ,Particle Size ,Physical and Theoretical Chemistry ,Quenching (fluorescence) ,Bioconjugation ,Chemistry ,Lasers ,Osmolar Concentration ,Serum Albumin, Bovine ,Chemical engineering ,Colloidal gold ,Cattle ,Gold ,Particle size - Abstract
Size control of laser-fabricated surfactant-free gold nanoparticles is a challenging endeavor. In this work, we show that size control can be achieved by adding ions with low salinity during synthesis. In addition, this approach offers the opportunity to fundamentally study ion interactions with bare nanoparticle surfaces and can help to elucidate the nanoparticle formation mechanism. The studies were carried out in a flow-through reactor and in the presence of NaCl, NaBr and sodium phosphate buffer at minimal ionic strengths. A significant size quenching effect at ionic strengths from 1-50 μM was found, which allowed surfactant-free nanoparticle size control with average diameters of 6-30 nm. This effect went along with low polydispersity and minimal aggregation tendencies and was confirmed by UV-vis spectroscopy, TEM, SEM and analytical disk centrifugation. Our findings indicate that size quenching originates from an anionic electrostatic stabilization depending on the nanoparticle surface area, which may be caused by specific ion adsorption. By subsequent delayed bioconjugation in liquid-flow using bovine serum albumin as a stabilizing agent, nano-bioconjugates with good stability in cell culture media were obtained, which are applicable in toxicology and cell biology.
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- 2013
12. Injection of ligand-free gold and silver nanoparticles into murine embryos does not impact pre-implantation development
- Author
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Svea Peterson, Wiebke Garrels, Annette Barchanski, Ulrich Baulain, Lisa Gamrad, Detlef Rath, Andrea Lucas-Hahn, Sabine Klein, Laszlo Sajti, Ulrike Taylor, Wilfried A. Kues, and Stephan Barcikowski
- Subjects
Dewey Decimal Classification::500 | Naturwissenschaften::540 | Chemie ,Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau ,General Physics and Astronomy ,Protein Corona ,confocal microscopy ,lcsh:Chemical technology ,Embryo development ,lcsh:Technology ,Full Research Paper ,Silver nanoparticle ,Nanotechnology ,Gold Nanoparticles ,lcsh:TP1-1185 ,General Materials Science ,lcsh:Science ,Ion concentrations ,Mammals ,Embryo ,lcsh:QC1-999 ,Polymerase chain reaction ,Biomedical applications ,Nanoscience ,medicine.anatomical_structure ,Colloidal gold ,Protein corona ,Toxicity ,embryonic structures ,ddc:540 ,ddc:620 ,Silver nanoparticles ,Medical applications ,Silver ,Chemie ,Biology ,Andrology ,protein corona ,medicine ,Protein coronas ,Blastocyst ,Electrical and Electronic Engineering ,Gold and silver nanoparticles ,lcsh:T ,Embryogenesis ,Biomedical application ,toxicity ,Blastomere ,Confocal microscopy ,gene expression ,Nanoparticles ,biomedical application ,lcsh:Q ,Gene expression ,Gold ,lcsh:Physics ,Internal controls - Abstract
Intended exposure to gold and silver nanoparticles has increased exponentially over the last decade and will continue to rise due to their use in biomedical applications. In particular, reprotoxicological aspects of these particles still need to be addressed so that the potential impacts of this development on human health can be reliably estimated. Therefore, in this study the toxicity of gold and silver nanoparticles on mammalian preimplantation development was assessed by injecting nanoparticles into one blastomere of murine 2 cell-embryos, while the sister blastomere served as an internal control. After treatment, embryos were cultured and embryo development up to the blastocyst stage was assessed. Development rates did not differ between microinjected and control groups (gold nanoparticles: 67.3%, silver nanoparticles: 61.5%, sham: 66.2%, handling control: 79.4%). Real-time PCR analysis of six developmentally important genes (BAX, BCL2L2, TP53, OCT4, NANOG, DNMT3A) did not reveal an influence on gene expression in blastocysts. Contrary to silver nanoparticles, exposure to comparable Ag+-ion concentrations resulted in an immediate arrest of embryo development. In conclusion, the results do not indicate any detrimental effect of colloidal gold or silver nanoparticles on the development of murine embryos.
- Published
- 2014
13. Current state of laser synthesis of metal and alloy nanoparticles as ligand-free reference materials for nano-toxicological assays
- Author
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Stephan Barcikowski, Detlef Rath, Jurij Jakobi, Daniela Tiedemann, Lisa Gamrad, Ulrike Taylor, Wilfried A. Kues, Christoph Rehbock, and Selina Beatrice van der Meer
- Subjects
Materials science ,Alloy ,Chemie ,General Physics and Astronomy ,Nanoparticle ,Nanotechnology ,Review ,engineering.material ,lcsh:Chemical technology ,lcsh:Technology ,size control ,wear debris ,Nanomaterials ,Nano ,implant alloy ,lcsh:TP1-1185 ,General Materials Science ,Electrical and Electronic Engineering ,lcsh:Science ,albumin ,Quenching ,Bioconjugation ,Laser ablation ,nickel-titanium ,lcsh:T ,gold-silver ,lcsh:QC1-999 ,Nanoscience ,laser ablation ,engineering ,Particle ,lcsh:Q ,lcsh:Physics - Abstract
Due to the abundance of nanomaterials in medical devices and everyday products, toxicological effects related to nanoparticles released from these materials, e.g., by mechanical wear, are a growing matter of concern. Unfortunately, appropriate nanoparticles required for systematic toxicological evaluation of these materials are still lacking. Here, the ubiquitous presence of surface ligands, remaining from chemical synthesis are a major drawback as these organic residues may cause cross-contaminations in toxicological studies. Nanoparticles synthesized by pulsed laser ablation in liquid are a promising alternative as this synthesis route provides totally ligand-free nanoparticles. The first part of this article reviews recent methods that allow the size control of laser-fabricated nanoparticles, focusing on laser post irradiation, delayed bioconjugation and in situ size quenching by low salinity electrolytes. Subsequent or parallel applications of these methods enable precise tuning of the particle diameters in a regime from 4–400 nm without utilization of any artificial surface ligands. The second paragraph of this article highlights the recent progress concerning the synthesis of composition controlled alloy nanoparticles by laser ablation in liquids. Here, binary and ternary alloy nanoparticles with totally homogeneous elemental distribution could be fabricated and the composition of these particles closely resembled bulk implant material. Finally, the model AuAg was used to systematically evaluate composition related toxicological effects of alloy nanoparticles. Here Ag+ ion release is identified as the most probable mechanism of toxicity when recent toxicological studies with gametes, mammalian cells and bacteria are considered.
- Published
- 2014
14. Gold nanoparticles interfere with sperm functionality by membrane adsorption without penetration
- Author
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Detlef Rath, Wilfried A. Kues, Svea Petersen, Lisa Gamrad, Ulrike Taylor, Annette Barchanski, Ulrich Baulain, Stephan Barcikowski, and Laszlo Sajti
- Subjects
Male ,endocrine system ,Materials science ,Biomedical Engineering ,Chemie ,Metal Nanoparticles ,Nanoparticle ,Nanotechnology ,Toxicology ,Cell membrane ,medicine ,Animals ,reproductive and urinary physiology ,Sperm motility ,urogenital system ,Cell Membrane ,Penetration (firestop) ,Spermatozoa ,Sperm ,Membrane ,medicine.anatomical_structure ,Colloidal gold ,Biophysics ,Surface modification ,Cattle ,Adsorption ,Gold - Abstract
To examine gold nanoparticle reprotoxicity, bovine spermatozoa were challenged with ligand-free or oligonucleotide-conjugated gold nanoparticles synthesized purely without any surfactants by laser ablation. Sperm motility declined at nanoparticle mass dose of 10 µg/ml (corresponding to ∼14 000 nanoparticles per sperm cell) regardless of surface modification. Sperm morphology and viability remained unimpaired at all concentrations. Transmission electron microscopy showed an modification dependant attachment of nanoparticles to the cell membrane of spermatozoa, but provided no evidence for nanoparticle entrance into sperm cells. A molecular examination revealed a reduction of free thiol residues on the cell membrane after nanoparticle exposure, which could explain the decrease in sperm motility. Sperm fertilising ability decreased after exposure to 10 µg/ml of ligand-free nanoparticles indicating that agglomerated ligand-free nanoparticles interfere with membrane properties necessary for fertilisation. In conclusion, nanoparticles may impair key sperm functions solely by interacting with the sperm surface membrane.
- Published
- 2013
15. Optical and electron microscopy study of laser-based intracellular molecule delivery using peptide-conjugated photodispersible gold nanoparticle agglomerates
- Author
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Judith Krawinkel, Undine Richter, Alexander Heisterkamp, Christoph Rehbock, Maria Leilani Torres-Mapa, Martin Westermann, Lisa Gamrad, and Stephan Barcikowski
- Subjects
Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie ,Light ,Molecular biology ,Metal Nanoparticles ,Nanoparticle ,Medicine (miscellaneous) ,Pharmaceutical Science ,High resolution transmission electron microscopy ,animal cell ,02 engineering and technology ,Cell-penetrating peptide ,01 natural sciences ,Applied Microbiology and Biotechnology ,Laser-based ,Cell membrane ,chemistry.chemical_compound ,Laser-based release ,Gold Nanoparticles ,Cell proliferation ,cellular distribution ,Laser ablation ,Agglomeration ,drug cytotoxicity ,021001 nanoscience & nanotechnology ,Endocytosis ,medicine.anatomical_structure ,Intracellular molecule delivery ,membrane damage ,Colloidal gold ,cytoplasm ,microscopy ,Molecular Medicine ,0210 nano-technology ,Medical applications ,Intracellular ,conjugation ,Cell Survival ,Cells ,Chemie ,Biomedical Engineering ,Metal nanoparticles ,Nanotechnology ,Bioengineering ,Endosomes ,010402 general chemistry ,Article ,Dogs ,Microscopy, Electron, Transmission ,Fiber optic sensors ,ddc:570 ,Cell Line, Tumor ,transmission electron microscopy ,Electron microscopy ,medicine ,endocytosis ,Animals ,Gold nanoparticles ,controlled study ,ddc:610 ,endosome ,cell viability ,Cell Proliferation ,Fluorescent Dyes ,nonhuman ,Lasers ,Research ,Cell Membrane ,Biological Transport ,Cell-penetrating peptides ,Molecules ,calcein ,laser ,0104 chemical sciences ,Calcein ,cell penetrating peptide ,chemistry ,Particle agglomerates ,Biophysics ,Nanoparticles ,Irradiation ,Gold ,Dewey Decimal Classification::600 | Technik::610 | Medizin, Gesundheit ,Pulsed lasers ,Cytology ,Peptides ,gold nanoparticle - Abstract
Background Cell-penetrating peptides (CPPs) can act as carriers for therapeutic molecules such as drugs and genetic constructs for medical applications. The triggered release of the molecule into the cytoplasm can be crucial to its effective delivery. Hence, we implemented and characterized laser interaction with defined gold nanoparticle agglomerates conjugated to CPPs which enables efficient endosomal rupture and intracellular release of molecules transported. Results Gold nanoparticles generated by pulsed laser ablation in liquid were conjugated with CPPs forming agglomerates and the intracellular release of molecules was triggered via pulsed laser irradiation (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\lambda$$\end{document}λ = 532 nm, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\tau _{pulse}$$\end{document}τpulse = 1 ns). The CPPs enhance the uptake of the agglomerates along with the cargo which can be co-incubated with the agglomerates. The interaction of incident laser light with gold nanoparticle agglomerates leads to heat deposition and field enhancement in the vicinity of the particles. This highly precise effect deagglomerates the nanoparticles and disrupts the enclosing endosomal membrane. Transmission electron microscopy images confirmed this rupture for radiant exposures of 25 mJ/cm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{2}$$\end{document}2 and above. Successful intracellular release was shown using the fluorescent dye calcein. For a radiant exposure of 35 mJ/cm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{2}$$\end{document}2 we found calcein delivery in 81 % of the treated cells while maintaining a high percentage of cell viability. Furthermore, cell proliferation and metabolic activity were not reduced 72 h after the treatment. Conclusion CPPs trigger the uptake of the gold nanoparticle agglomerates via endocytosis and co-resident molecules in the endosomes are released by applying laser irradiation, preventing their intraendosomal degradation. Due to the highly localized effect, the cell membrane integrity is not affected. Therefore, this technique can be an efficient tool for spatially and temporally confined intracellular release. The utilization of specifically designed photodispersible gold nanoparticle agglomerates (65 nm) can open novel avenues in imaging and molecule delivery. Due to the induced deagglomeration the primary, small particles (~5 nm) are more likely to be removed from the body. Electronic supplementary material The online version of this article (doi:10.1186/s12951-015-0155-8) contains supplementary material, which is available to authorized users.
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