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Current Nanoscience

Editor-in-Chief

ISSN (Print): 1573-4137
ISSN (Online): 1875-6786

Research Article

Interference of Gold Nanoparticles with In vitro Endotoxin Detection Assays

Author(s): Melissa A. Vetten* and Mary Gulumian

Volume 16, Issue 2, 2020

Page: [204 - 213] Pages: 10

DOI: 10.2174/1573413715666181212120013

Price: $65

Abstract

Background: Endotoxin-free engineered nanoparticle suspensions are imperative for their successful applications in the field of nanomedicine as well as in the investigations in their toxicity. Gold nanoparticles are known to interfere with various in vitro assays due to their optical properties and potential for surface reactivity. In vitro endotoxin testing assays are known to be susceptible to interference caused by the sample being tested.

Objective: This study aimed to identify a preferred assay for the testing of endotoxin contamination in gold nanoparticle suspensions.

Methods: The interference by gold nanoparticles on three assays namely, the commonly used limulus amebocyte lysate chromogenic assay, the limulus amebocyte lysate gel-clot method, and the less common recombinant Factor C (rFC) assay, was tested.

Results: Possible interference could be observed with all three assays. The interference with the absorbance- based chromogenic assay could not be overcome by dilution; whilst the qualitative nature of the gel-clot assay excluded the possibility of distinguishing between a false positive result due to enhancement of the sensitivity of the assay, and genuine endotoxin contamination. However, interference with the rFC assay was easily overcome through dilution.

Conclusion: The rFC assay is recommended as an option for endotoxin contamination detection in gold nanoparticle suspensions.

Keywords: Endotoxins, Contamination, Gold nanoparticles, in vitro, Interference, LAL assay.

Graphical Abstract
[1]
Cabuzu, D.; Cirja, A.; Puiu, R.; Grumezescu, A.M. Biomedical applications of gold nanoparticles. Curr. Top. Med. Chem., 2015, 15(16), 1605-1613.
[http://dx.doi.org/10.2174/1568026615666150414144750] [PMID: 25877087]
[2]
Karthikeyan, S.; Hossein, H.; Ameen, K.; Mohsen, H.; Yashwant, P. Targeting nanoparticles as drug delivery systems for cancer treatment. Curr. Nanosci., 2009, 5(2), 135-140.
[http://dx.doi.org/10.2174/157341309788185406]
[3]
Di, W.; Xiao-Dong, Z.; Pei-Xun, L.; Liang-An, Z.; Fei-Yue, F.; Mei-Li, G. Gold nanostructure: Fabrication, surface modification, targeting imaging, and enhanced radiotherapy. Curr. Nanosci., 2011, 7(1), 110-118.
[http://dx.doi.org/10.2174/157341311794480246]
[4]
Kodiha, M.; Wang, Y.M.; Hutter, E.; Maysinger, D.; Stochaj, U. Off to the organelles - killing cancer cells with targeted gold nanoparticles. Theranostics, 2015, 5(4), 357-370.
[http://dx.doi.org/10.7150/thno.10657] [PMID: 25699096]
[5]
Huang, X.; El-Sayed, M.A. Gold nanoparticles: Optical properties and implementations in cancer diagnosis and photothermal therapy. J. Adv. Res., 2010, 1(1), 13-28.
[http://dx.doi.org/10.1016/j.jare.2010.02.002]
[6]
Fratoddi, I.; Venditti, I.; Battocchio, C.; Polzonetti, G.; Cametti, C.; Russo, M.V. Core shell hybrids based on noble metal nanoparticles and conjugated polymers: synthesis and characterization. Nanoscale Res. Lett., 2011, 6(1), 98.
[http://dx.doi.org/10.1186/1556-276X-6-98] [PMID: 21711612]
[7]
Vetten, M.A.; Yah, C.S.; Singh, T.; Gulumian, M. Challenges facing sterilization and depyrogenation of nanoparticles: effects on structural stability and biomedical applications. Nanomedicine (Lond.), 2014, 10(7), 1391-1399.
[http://dx.doi.org/10.1016/j.nano.2014.03.017] [PMID: 24709329]
[8]
Wang, L.; Du, J.; Zhou, Y.; Wang, Y. Safety of nanosuspensions in drug delivery. Nanomedicine (Lond.), 2017, 13(2), 455-469.
[http://dx.doi.org/10.1016/j.nano.2016.08.007] [PMID: 27558350]
[9]
Li, Y.; Boraschi, D. Endotoxin contamination: a key element in the interpretation of nanosafety studies. Nanomedicine (Lond.), 2016, 11(3), 269-287.
[http://dx.doi.org/10.2217/nnm.15.196] [PMID: 26787429]
[10]
Vallhov, H.; Qin, J.; Johansson, S.M.; Ahlborg, N.; Muhammed, M.A.; Scheynius, A.; Gabrielsson, S. The importance of an endotoxin-free environment during the production of nanoparticles used in medical applications. Nano Lett., 2006, 6(8), 1682-1686.
[http://dx.doi.org/10.1021/nl060860z] [PMID: 16895356]
[11]
Inoue, K.; Takano, H.; Yanagisawa, R.; Hirano, S.; Sakurai, M.; Shimada, A.; Yoshikawa, T. Effects of airway exposure to nanoparticles on lung inflammation induced by bacterial endotoxin in mice. Environ. Health Perspect., 2006, 114(9), 1325-1330.
[http://dx.doi.org/10.1289/ehp.8903] [PMID: 16966083]
[12]
Oostingh, G.J.; Casals, E.; Italiani, P.; Colognato, R.; Stritzinger, R.; Ponti, J.; Pfaller, T.; Kohl, Y.; Ooms, D.; Favilli, F.; Leppens, H.; Lucchesi, D.; Rossi, F.; Nelissen, I.; Thielecke, H.; Puntes, V.F.; Duschl, A.; Boraschi, D. Problems and challenges in the development and validation of human cell-based assays to determine nanoparticle-induced immunomodulatory effects. Part. Fibre Toxicol., 2011, 8(1), 8.
[http://dx.doi.org/10.1186/1743-8977-8-8] [PMID: 21306632]
[13]
Jones, C.F.; Grainger, D.W. In vitro assessments of nanomaterial toxicity. Adv. Drug Deliv. Rev., 2009, 61(6), 438-456.
[http://dx.doi.org/10.1016/j.addr.2009.03.005] [PMID: 19383522]
[14]
Li, Y.; Fujita, M.; Boraschi, D. Endotoxin contamination in nanomaterials leads to the misinterpretation of immunosafety results. Front. Immunol., 2017, 8, 472.
[http://dx.doi.org/10.3389/fimmu.2017.00472] [PMID: 28533772]
[15]
Magalhães, P.O.; Lopes, A.M.; Mazzola, P.G.; Rangel-Yagui, C.; Penna, T.C.; Pessoa, A., Jr Methods of endotoxin removal from biological preparations: a review. J. Pharm. Pharm. Sci., 2007, 10(3), 388-404.
[PMID: 17727802]
[16]
Gorbet, M.B.; Sefton, M.V. Endotoxin: the uninvited guest. Biomaterials, 2005, 26(34), 6811-6817.
[http://dx.doi.org/10.1016/j.biomaterials.2005.04.063] [PMID: 16019062]
[17]
Bayston, K.F.; Cohen, J. Bacterial endotoxin and current concepts in the diagnosis and treatment of endotoxaemia. J. Med. Microbiol., 1990, 31(2), 73-83.
[http://dx.doi.org/10.1099/00222615-31-2-73] [PMID: 2406448]
[18]
Iwanaga, S. Biochemical principle of Limulus test for detecting bacterial endotoxins. Proc. Jpn. Acad., Ser. B, Phys. Biol. Sci., 2007, 83(4), 110-119.
[http://dx.doi.org/10.2183/pjab.83.110] [PMID: 24019589]
[19]
Iwanaga, S.; Miyata, T.; Tokunaga, F.; Muta, T. Molecular mechanism of hemolymph clotting system in Limulus. Thromb. Res., 1992, 68(1), 1-32.
[http://dx.doi.org/10.1016/0049-3848(92)90124-S] [PMID: 1448796]
[20]
Iwanaga, S. The molecular basis of innate immunity in the horseshoe crab. Curr. Opin. Immunol., 2002, 14(1), 87-95.
[http://dx.doi.org/10.1016/S0952-7915(01)00302-8] [PMID: 11790537]
[21]
Muta, T.; Iwanaga, S. The role of hemolymph coagulation in innate immunity. Curr. Opin. Immunol., 1996, 8(1), 41-47.
[http://dx.doi.org/10.1016/S0952-7915(96)80103-8] [PMID: 8729445]
[22]
Novitsky, T.J. Biomedical Applications of Limulus Amebocyte Lysate. In Tanacredi, J.T.; Botton, M.L.; Smith, D. (eds.)Biology and Conservation of Horseshoe Crabs; Springer, 2009, pp. 315-329.
[http://dx.doi.org/10.1007/978-0-387-89959-6_20]
[23]
Blechová, R.; Pivodová, D. Limulus Amoebocyte Lysate (LAL) Test - An alternative method for detection of bacterial endotoxins. Acta Vet. Brno, 2001, 70, 291-296.
[http://dx.doi.org/10.2754/avb200170030291]
[24]
Lindsay, G.K.; Roslansky, P.F.; Novitsky, T.J. Single-step, chromogenic Limulus amebocyte lysate assay for endotoxin. J. Clin. Microbiol., 1989, 27(5), 947-951.
[http://dx.doi.org/10.1128/JCM.27.5.947-951.1989] [PMID: 2745704]
[25]
Nachum, R.; Berzofsky, R.N. Chromogenic Limulus amoebocyte lysate assay for rapid detection of gram-negative bacteriuria. J. Clin. Microbiol., 1985, 21(5), 759-763.
[http://dx.doi.org/10.1128/JCM.21.5.759-763.1985] [PMID: 3998106]
[26]
Svensson, A.; Hahn-Hägerdal, B. Comparison of a gelation and a chromogenic Limulus (LAL) assay for the detection of gram-negative bacteria, and the application of the latter assay to milk. J. Dairy Res., 1987, 54(2), 267-273.
[http://dx.doi.org/10.1017/S0022029900025401] [PMID: 3597923]
[27]
Crist, R.M.; Grossman, J.H.; Patri, A.K.; Stern, S.T.; Dobrovolskaia, M.A.; Adiseshaiah, P.P.; Clogston, J.D.; McNeil, S.E. Common pitfalls in nanotechnology: lessons learned from NCI’s Nanotechnology Characterization Laboratory. Integr. Biol., 2013, 5(1), 66-73.
[http://dx.doi.org/10.1039/c2ib20117h] [PMID: 22772974]
[28]
Oishi, H.; Fusamoto, M.; Hatayama, Y.; Tsuchiya, M.; Takaoka, A.; Sakata, Y. An automated analysis system of Limulus Amebocyte Lysate (LAL)-endotoxin reaction kinetics using turbidimetric kinetic assay. Chem. Pharm. Bull. (Tokyo), 1988, 36(8), 3012-3019.
[http://dx.doi.org/10.1248/cpb.36.3012] [PMID: 3240508]
[29]
Morita, T.; Tanaka, S.; Nakamura, T.; Iwanaga, S. A new (1→3)‐β‐D‐glucan‐mediated coagulation pathway found in limulus amebocytes. FEBS Lett., 1981, 129(2), 318-321.
[http://dx.doi.org/10.1016/0014-5793(81)80192-5] [PMID: 6790304]
[30]
Wright, W.F.; Overman, S.B.; Ribes, J.A. (1–3)-β-D-Glucan assay: A review of its laboratory and clinical application. Lab. Med., 2011, 42(11), 679-685.
[http://dx.doi.org/10.1309/LM8BW8QNV7NZBROG]
[31]
Kędzierska, A.; Kochan, P.; Pietrzyk, A.; Kędzierska, J. Current status of fungal cell wall components in the immunodiagnostics of invasive fungal infections in humans: galactomannan, mannan and (1→3)-β-D-glucan antigens. Eur. J. Clin. Microbiol. Infect. Dis., 2007, 26(11), 755-766.
[http://dx.doi.org/10.1007/s10096-007-0373-6] [PMID: 17671803]
[32]
Anderson, J.; Eller, M.; Finkelman, M.; Birx, D.; Schlesinger-Frankel, S.; Marovich, M. False positive endotoxin results in a DC product caused by (1→3)-β-D-glucans acquired from a sterilizing cellulose filter. Cytotherapy, 2002, 4(6), 557-559.
[http://dx.doi.org/10.1080/146532402761624728] [PMID: 12568992]
[33]
Ding, J.L.; Ho, B. A new era in pyrogen testing. Trends Biotechnol., 2001, 19(8), 277-281.
[http://dx.doi.org/10.1016/S0167-7799(01)01694-8] [PMID: 11451451]
[34]
Abate, W.; Sattar, A.A.; Liu, J.; Conway, M.E.; Jackson, S.K. Evaluation of recombinant factor C assay for the detection of divergent lipopolysaccharide structural species and comparison with Limulus amebocyte lysate-based assays and a human monocyte activity assay. J. Med. Microbiol., 2017, 66(7), 888-897.
[http://dx.doi.org/10.1099/jmm.0.000510] [PMID: 28693666]
[35]
Das, A.P.; Kumar, P.S.; Swain, S. Recent advances in biosensor based endotoxin detection. Biosens. Bioelectron., 2014, 51, 62-75.
[http://dx.doi.org/10.1016/j.bios.2013.07.020] [PMID: 23934306]
[36]
Obayashi, T.; Tamura, H.; Tanaka, S.; Ohki, M.; Takahashi, S.; Arai, M.; Masuda, M.; Kawai, T. A new chromogenic endotoxin-specific assay using recombined limulus coagulation enzymes and its clinical applications. Clin. Chim. Acta, 1985, 149(1), 55-65.
[http://dx.doi.org/10.1016/0009-8981(85)90273-6] [PMID: 3896576]
[37]
Saito, R.; Cranmer, B.K.; Tessari, J.D.; Larsson, L.; Mehaffy, J.M.; Keefe, T.J.; Reynolds, S.J. Recombinant factor C (rFC) assay and gas chromatography/mass spectrometry (GC/MS) analysis of endotoxin variability in four agricultural dusts. Ann. Occup. Hyg., 2009, 53(7), 713-722.
[PMID: 19638393]
[38]
Thorne, P.S.; Perry, S.S.; Saito, R.; O’Shaughnessy, P.T.; Mehaffy, J.; Metwali, N.; Keefe, T.; Donham, K.J.; Reynolds, S.J. Evaluation of the Limulus amebocyte lysate and recombinant factor C assays for assessment of airborne endotoxin. Appl. Environ. Microbiol., 2010, 76(15), 4988-4995.
[http://dx.doi.org/10.1128/AEM.00527-10] [PMID: 20525858]
[39]
Poole, J.A.; Dooley, G.P.; Saito, R.; Burrell, A.M.; Bailey, K.L.; Romberger, D.J.; Mehaffy, J.; Reynolds, S.J. Muramic acid, endotoxin, 3-hydroxy fatty acids, and ergosterol content explain monocyte and epithelial cell inflammatory responses to agricultural dusts. J. Toxicol. Environ. Health A, 2010, 73(10), 684-700.
[http://dx.doi.org/10.1080/15287390903578539] [PMID: 20391112]
[40]
Burch, J.B.; Svendsen, E.; Siegel, P.D.; Wagner, S.E.; von Essen, S.; Keefe, T.; Mehaffy, J.; Martinez, A.S.; Bradford, M.; Baker, L.; Cranmer, B.; Saito, R.; Tessari, J.; Linda, P.; Andersen, C.; Christensen, O.; Koehncke, N.; Reynolds, S.J. Endotoxin exposure and inflammation markers among agricultural workers in Colorado and Nebraska. J. Toxicol. Environ. Health A, 2010, 73(1), 5-22.
[http://dx.doi.org/10.1080/15287390903248604] [PMID: 19953416]
[41]
Alwis, K.U.; Milton, D.K. Recombinant factor C assay for measuring endotoxin in house dust: comparison with LAL, and (1→3)-β-D-glucans. Am. J. Ind. Med., 2006, 49(4), 296-300.
[http://dx.doi.org/10.1002/ajim.20264] [PMID: 16550568]
[42]
Matsui, E.C.; Hansel, N.N.; Aloe, C.; Schiltz, A.M.; Peng, R.D.; Rabinovitch, N.; Ong, M.J.; Williams, D.L.; Breysse, P.N.; Diette, G.B.; Liu, A.H. Indoor pollutant exposures modify the effect of airborne endotoxin on asthma in urban children. Am. J. Respir. Crit. Care Med., 2013, 188(10), 1210-1215.
[http://dx.doi.org/10.1164/rccm.201305-0889OC] [PMID: 24066676]
[43]
Ownby, D.R.; Peterson, E.L.; Williams, L.K.; Zoratti, E.M.; Wegienka, G.R.; Woodcroft, K.J.; Joseph, C.L.; Johnson, C.C. Variation of dust endotoxin concentrations by location and time within homes of young children. Pediatr. Allergy Immunol., 2010, 21(3), 533-540.
[http://dx.doi.org/10.1111/j.1399-3038.2009.00918.x] [PMID: 20088861]
[44]
Kroll, A.; Pillukat, M.H.; Hahn, D.; Schnekenburger, J. Interference of engineered nanoparticles with in vitro toxicity assays. Arch. Toxicol., 2012, 86(7), 1123-1136.
[http://dx.doi.org/10.1007/s00204-012-0837-z] [PMID: 22407301]
[45]
Smulders, S.; Kaiser, J-P.; Zuin, S.; Van Landuyt, K.L.; Golanski, L.; Vanoirbeek, J.; Wick, P.; Hoet, P.H. Contamination of nanoparticles by endotoxin: evaluation of different test methods. Part. Fibre Toxicol., 2012, 9(1), 41.
[http://dx.doi.org/10.1186/1743-8977-9-41] [PMID: 23140310]
[46]
Dobrovolskaia, M.A.; Neun, B.W.; Clogston, J.D.; Ding, H.; Ljubimova, J.; McNeil, S.E. Ambiguities in applying traditional Limulus amebocyte lysate tests to quantify endotoxin in nanoparticle formulations. Nanomedicine (Lond.), 2010, 5(4), 555-562.
[http://dx.doi.org/10.2217/nnm.10.29] [PMID: 20528451]
[47]
Dobrovolskaia, M.A.; Germolec, D.R.; Weaver, J.L. Evaluation of nanoparticle immunotoxicity. Nat. Nanotechnol., 2009, 4(7), 411-414.
[http://dx.doi.org/10.1038/nnano.2009.175] [PMID: 19581891]
[48]
Neun, B.W.; Dobrovolskaia, M.A. Detection and quantitative evaluation of endotoxin contamination in nanoparticle formulations by LAL-based assays. Methods Mol. Biol., 2011, 697, 121-130.
[http://dx.doi.org/10.1007/978-1-60327-198-1_12] [PMID: 21116960]
[49]
Kucki, M.; Cavelius, C.; Kraegeloh, A. Interference of silica nanoparticles with the traditional Limulus amebocyte lysate gel clot assay. Innate Immun., 2014, 20(3), 327-336.
[http://dx.doi.org/10.1177/1753425913492833] [PMID: 23884096]
[50]
Kroll, A.; Pillukat, M.H.; Hahn, D.; Schnekenburger, J. Current in vitro methods in nanoparticle risk assessment: limitations and challenges. Eur. J. Pharm. Biopharm., 2009, 72(2), 370-377.
[http://dx.doi.org/10.1016/j.ejpb.2008.08.009] [PMID: 18775492]
[51]
Almutary, A.; Sanderson, B.J.S. Up to date in-vitro Artefacts in the detection of nanoparticles toxicity: Short Review. J. Ecol. Toxicol., 2017, 1(1), 2.
[52]
FDA, Guidance for Industry: Pyrogen and Endotoxin Testing - Questions and Answers. Administration, U. S. D. o. H. a. H. S. F. a. D., Ed. 2012.
[53]
McCullough, K.Z.; Weidner-Loeven, C. Variability in the LAL test: comparison of three kinetic methods for the testing of pharmaceutical products. J. Parenter. Sci. Technol., 1992, 46(3), 69-72.
[PMID: 1522443]
[54]
Ong, K.J.; MacCormack, T.J.; Clark, R.J.; Ede, J.D.; Ortega, V.A.; Felix, L.C.; Dang, M.K.; Ma, G.; Fenniri, H.; Veinot, J.G.; Goss, G.G. Widespread nanoparticle-assay interference: implications for nanotoxicity testing. PLoS One, 2014, 9(3), e90650
[http://dx.doi.org/10.1371/journal.pone.0090650] [PMID: 24618833]
[55]
Alkilany, A.M.; Murphy, C.J. Toxicity and cellular uptake of gold nanoparticles: what we have learned so far? J. Nanopart. Res., 2010, 12(7), 2313-2333.
[http://dx.doi.org/10.1007/s11051-010-9911-8] [PMID: 21170131]
[56]
Stone, V.; Johnston, H.; Schins, R.P. Development of in vitro systems for nanotoxicology: methodological considerations. Crit. Rev. Toxicol., 2009, 39(7), 613-626.
[http://dx.doi.org/10.1080/10408440903120975] [PMID: 19650720]
[57]
Vetten, M.A.; Tlotleng, N.; Tanner Rascher, D.; Skepu, A.; Keter, F.K.; Boodhia, K.; Koekemoer, L.A.; Andraos, C.; Tshikhudo, R.; Gulumian, M. Label-free in vitro toxicity and uptake assessment of citrate stabilised gold nanoparticles in three cell lines. Part. Fibre Toxicol., 2013, 10, 50.
[http://dx.doi.org/10.1186/1743-8977-10-50] [PMID: 24103467]
[58]
Li, Y.; Italiani, P.; Casals, E.; Tran, N.; Puntes, V.F.; Boraschi, D. Optimising the use of commercial LAL assays for the analysis of endotoxin contamination in metal colloids and metal oxide nanoparticles. Nanotoxicology, 2015, 9(4), 462-473.
[http://dx.doi.org/10.3109/17435390.2014.948090] [PMID: 25119419]
[59]
Frens, G. Controlled nucleation for the regulation of the particle size in monodisperse gold suspensions. Nat. Phys. Sci (Lond.), 1973, 241, 20-22.
[http://dx.doi.org/10.1038/physci241020a0]
[60]
Turkevich, J.; Stevenson, P.C.; Hillier, J. A study of the nucleation and growth processes in the synthesis of colloidal gold. Discuss. Faraday Soc., 1951, 11, 55-75.
[http://dx.doi.org/10.1039/df9511100055]
[61]
Li, C.; Li, D.; Wan, G.; Xu, J.; Hou, W. Facile synthesis of concentrated gold nanoparticles with low size-distribution in water: temperature and pH controls. Nanoscale Res. Lett., 2011, 6(1), 440.
[http://dx.doi.org/10.1186/1556-276X-6-440] [PMID: 21733153]
[62]
Zabetakis, K.; Ghann, W.E.; Kumar, S.; Daniel, M-C. Effect of high gold salt concentrations on the size and polydispersity of gold nanoparticles prepared by an extended Turkevich-Frens method. Gold Bull., 2012, 45, 203-211.
[http://dx.doi.org/10.1007/s13404-012-0069-2]
[63]
Link, S.; El-Sayed, M.A. Size and temperature dependence of the plasmon absorption of colloidal gold nanoparticles. J. Phys. Chem. B, 1999, 103(21), 4212-4217.
[http://dx.doi.org/10.1021/jp984796o]
[64]
Jain, P.K.; Lee, K.S.; El-Sayed, I.H.; El-Sayed, M.A. Calculated absorption and scattering properties of gold nanoparticles of different size, shape, and composition: applications in biological imaging and biomedicine. J. Phys. Chem. B, 2006, 110(14), 7238-7248.
[http://dx.doi.org/10.1021/jp057170o] [PMID: 16599493]
[65]
Fraga, S.; Faria, H.; Soares, M.E.; Duarte, J.A.; Soares, L.; Pereira, E.; Costa-Pereira, C.; Teixeira, J.P.; de Lourdes Bastos, M.; Carmo, H. Influence of the surface coating on the cytotoxicity, genotoxicity and uptake of gold nanoparticles in human HepG2 cells. J. Appl. Toxicol., 2013, 33(10), 1111-1119.
[http://dx.doi.org/10.1002/jat.2865] [PMID: 23529830]
[66]
Brewer, S.H.; Glomm, W.R.; Johnson, M.C.; Knag, M.K.; Franzen, S. Probing BSA binding to citrate-coated gold nanoparticles and surfaces. Langmuir, 2005, 21(20), 9303-9307.
[http://dx.doi.org/10.1021/la050588t] [PMID: 16171365]
[67]
Schlinkert, P.; Casals, E.; Boyles, M.; Tischler, U.; Hornig, E.; Tran, N.; Zhao, J.; Himly, M.; Riediker, M.; Oostingh, G.J.; Puntes, V.; Duschl, A. The oxidative potential of differently charged silver and gold nanoparticles on three human lung epithelial cell types. J. Nanobiotechnology, 2015, 13, 1.
[http://dx.doi.org/10.1186/s12951-014-0062-4] [PMID: 25592092]
[68]
Uboldi, C.; Bonacchi, D.; Lorenzi, G.; Hermanns, M.I.; Pohl, C.; Baldi, G.; Unger, R.E.; Kirkpatrick, C.J. Gold nanoparticles induce cytotoxicity in the alveolar type-II cell lines A549 and NCIH441. Part. Fibre Toxicol., 2009, 6, 18.
[http://dx.doi.org/10.1186/1743-8977-6-18] [PMID: 19545423]
[69]
Abdelhalim, M.A.K.; Mady, M.M.; Ghannam, M.M. Physical properties of different gold nanoparticles: Ultraviolet-Visible and fluorescence measurements. J. Nanomed. Nanotechnol., 2012, 3, 133.
[http://dx.doi.org/10.4172/2157-7439.1000133]
[70]
Dobrovolskaia, M.A. Pre-clinical immunotoxicity studies of nanotechnology- formulated drugs: Challenges, considerations and strategy. J. Control. Release, 2015, 220(Pt B), 71-583.
[http://dx.doi.org/10.1016/j.jconrel.2015.08.056] [PMID: 26348388]
[71]
Dawson, M.E. Maximum valid dilution and minimum valid concentration. LAL Update, 1995, 13(3), 1-6.
[72]
Dawson, E. Interference with the LAL test and how to address it. Available from: http://www.acciusa.com/pdfs/newsletter/LAL%20Update%20Vol%2022_No3%20rev%20001.pdf (Accessed on: 29 January 2018)
[73]
Dick, H.B.; Augustin, A.J.; Pakula, T.; Pfeiffer, N. Endotoxins in ophthalmic viscosurgical devices. Eur. J. Ophthalmol., 2003, 13(2), 176-184.
[http://dx.doi.org/10.1177/112067210301300209] [PMID: 12696637]
[74]
Ryan, J. Endotoxins and cell culture; Corning Life Sciences Technical Bulletin, 2004, pp. 1-8.
[75]
Wager, K.; Chui, T.; Adem, S. Effect of pH on the stability of gold nanoparticles and their application for melamine detection in infant formula. J. Appl. Chem., 2014, 7(8), 5.
[http://dx.doi.org/10.9790/5736-07821520]

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