TY - CONF A1 - Drescher, Daniela T1 - Raman spectroscopy on nanoparticle-influenced cellular systems T2 - Jubiläumssymposium Licht-Materialien-Modelle "100 Jahre Innovation aus Adlershof" CY - Berlin, Germany DA - 2009-09-07 PY - 2009 AN - OPUS4-20032 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Drescher, Daniela T1 - Combined intracellular SERS and cytotoxicity studies after uptake of silica nanoparticles T2 - FTIR Workshop, Robert-Koch-Institut CY - Berlin, Germany DA - 2009-10-15 PY - 2009 AN - OPUS4-20034 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Orts Gil, Guillermo A1 - Natte, Kishore A1 - Drescher, Daniela A1 - Bresch, Harald A1 - Mantion, Alexandre A1 - Kneipp, J. A1 - Österle, Werner T1 - Characterisation of silica nanoparticles prior to in vitro studies: from primary particles to agglomerates N2 - The size, surface charge and agglomeration state of nanoparticles under physiological conditions are fundamental parameters to be determined prior to their application in toxicological studies. Although silica-based materials are among the most promising candidates for biomedical applications, more systematic studies concerning the characterisation before performing toxicological studies are necessary. This interest is based on the necessity to elucidate the mechanisms affecting its toxicity. We present here TEM, SAXS and SMPS as a combination of methods allowing an accurate determination of single nanoparticle sizes. For the commercial material, Ludox TM50 single particle sizes around 30 nm were found in solution. DLS measurements of single particles are rather affected by polydispersity and particles concentration but this technique is useful to monitor their agglomeration state. Here, the influence of nanoparticle concentration, ionic strength (IS), pH and bath sonication on the agglomeration behaviour of silica particles in solution has been systematically investigated. Moreover, the colloidal stability of silica particles in the presence of BSA has been investigated showing a correlation between silica and protein concentrations and the formation of agglomerates. Finally, the colloidal stability of silica particles in standard cell culture medium has been tested, concluding the necessity of surface modification in order to preserve silica as primary particles in the presence of serum. The results presented here have major implications on toxicity investigations because silica agglomeration will change the probability and uptake mechanisms and thereby may affect toxicity. KW - Silica KW - Toxicology KW - Agglomeration KW - BSA KW - Nanoparticles KW - Characterisation PY - 2011 DO - https://doi.org/10.1007/s11051-010-9910-9 SN - 1388-0764 SN - 1572-896X VL - 13 IS - 4 SP - 1593 EP - 1604 PB - Springer AN - OPUS4-21179 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Drescher, Daniela T1 - Investigation of cytotoxicity of silica nanoparticles using viability tetsts and surface-enhanced Raman spectroscopy T2 - Nanobio International 2010 CY - Zurich, Switzerland DA - 2010-09-24 PY - 2010 AN - OPUS4-22667 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Matschulat, Andrea A1 - Drescher, Daniela A1 - Kneipp, Janina T1 - Surface-enhanced Raman scattering hybrid nanoprobe multiplexing and imaging in biological systems N2 - Surface-enhanced Raman scattering (SERS) labels and probes consisting of gold and silver nanoaggregates and attached reporter molecules can be identified by the Raman signature of the reporter molecule. At the same time, SERS hybrid probes deliver sensitive molecular structural information on their nanoenvironment. Here we demonstrate full exploitation of the multifunctional and multiplexing capabilities inherent to such nanoprobes by applying cluster methods and principal components approaches for discrimination beyond the visual inspection of individual spectra that has been practiced so far. The reported results indicate that fast, multivariate evaluation of whole sets of multiple probes is feasible. Spectra of five different reporters were shown to be separable by hierarchical clustering and by principal components analysis (PCA). In a duplex imaging approach in live cells, hierarchical cluster analysis, K-means clustering, and PCA were used for imaging the positions of different types of SERS probes along with the spectral information from cellular constituents. Parallel to cellular imaging experiments, cytotoxicity of the SERS hybrid probes containing aromatic thiols as reporters is assessed. The reported results suggest multiplexing applications of the nontoxic SERS nanoprobes in high density sensing and imaging in complex biological structures. KW - Surface-enhanced Raman scattering KW - Nanosensor KW - Para-aminobenzenethiol KW - 2-naphthalenethiol KW - 3T3 cells KW - Principal component analysis KW - Hierarchical cluster analysis KW - Cytotoxicity KW - Imaging PY - 2010 DO - https://doi.org/10.1021/nn100280z SN - 1936-0851 VL - 4 IS - 6 SP - 3259 EP - 3269 PB - ACS Publ. CY - Washington, DC, USA AN - OPUS4-23212 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Drescher, Daniela T1 - Investigation of cytotoxicity of silica nanoparticles using viability tests and surface-enhanced Raman spectroscopy T2 - Berliner Chemie Symposium CY - Berlin, Germany DA - 2011-04-07 PY - 2011 AN - OPUS4-23451 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Drescher, Daniela T1 - Biological mulitplex applications of optical nanoprobes in live cells T2 - International Symposium "Molecular Plasmonics" CY - Jena, Germany DA - 2011-05-19 PY - 2011 AN - OPUS4-23452 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Drescher, Daniela A1 - Orts Gil, Guillermo A1 - Laube, G. A1 - Natte, Kishore A1 - Veh, R.W. A1 - Österle, Werner A1 - Kneipp, Janina T1 - Toxicity of amorphous silica nanoparticles on eukaryotic cell model is determined by particle agglomeration and serum protein adsorption effects N2 - Cell cultures form the basis of most biological assays conducted to assess the cytotoxicity of nanomaterials. Since the molecular environment of nanoparticles exerts influence on their physicochemical properties, it can have an impact on nanotoxicity. Here, toxicity of silica nanoparticles upon delivery by fluid-phase uptake is studied in a 3T3 fibroblast cell line. Based on XTT viability assay, cytotoxicity is shown to be a function of (1) particle concentration and (2) of fetal calf serum (FCS) content in the cell culture medium. Application of dynamic light scattering shows that both parameters affect particle agglomeration. The DLS Experiments verify the stability of the nanoparticles in culture medium without FCS over a wide range of particle concentrations. The related toxicity can be mainly accounted for by single silica nanoparticles and small agglomerates. In contrast, agglomeration of silica nanoparticles in all FCS-containing media is observed, resulting in a decrease of the associated toxicity. This result has implications for the evaluation of the cytotoxic potential of silica nanoparticles and possibly also other nanomaterials in standard cell culture. KW - Agglomeration KW - Cytotoxicity KW - Fibroblast cells KW - Serum proteins KW - Silica nanoparticles PY - 2011 DO - https://doi.org/10.1007/s00216-011-4893-7 SN - 1618-2642 SN - 1618-2650 VL - 400 IS - 5 SP - 1367 EP - 1373 PB - Springer CY - Berlin AN - OPUS4-23678 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Drescher, Daniela T1 - Biological multiplex applications of optical nanoprobes in live cells T2 - Tag der Chemie CY - Berlin, Germany DA - 2011-07-13 PY - 2011 AN - OPUS4-24184 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Drescher, Daniela T1 - Biological multiplex applications of optical nanoprobes in live cells T2 - Tag der Chemie CY - Berlin, Germany DA - 2011-07-13 PY - 2011 AN - OPUS4-24185 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Drescher, Daniela T1 - Combining SERS and viablility tests for the investigation of nanotoxicity T2 - ESCBM - 14th European Conference on the Spectroscopy of Biological Molecules CY - Coimbra, Portugal DA - 2011-08-29 PY - 2011 AN - OPUS4-24186 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -