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Heße C, Kollenda S, Rotan O, Pastille E, Adamczyk A, Wenzek C, Hansen W, Epple M, Buer J, Westendorf AM, Knuschke T. A Tumor-Peptide–Based Nanoparticle Vaccine Elicits Efficient Tumor Growth Control in Antitumor Immunotherapy. Mol Cancer Ther 2019; 18:1069-1080. [DOI: 10.1158/1535-7163.mct-18-0764] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 12/19/2018] [Accepted: 04/04/2019] [Indexed: 11/16/2022]
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Knuschke T, Rotan O, Bayer W, Kollenda S, Dickow J, Sutter K, Hansen W, Dittmer U, Lang KS, Epple M, Buer J, Westendorf AM. Induction of Type I Interferons by Therapeutic Nanoparticle-Based Vaccination Is Indispensable to Reinforce Cytotoxic CD8 + T Cell Responses During Chronic Retroviral Infection. Front Immunol 2018; 9:614. [PMID: 29740425 PMCID: PMC5924795 DOI: 10.3389/fimmu.2018.00614] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 03/12/2018] [Indexed: 11/29/2022] Open
Abstract
T cell dysfunction and immunosuppression are characteristic for chronic viral infections and contribute to viral persistence. Overcoming these burdens is the goal of new therapeutic strategies to cure chronic infectious diseases. We recently described that therapeutic vaccination of chronic retrovirus infected mice with a calcium phosphate (CaP) nanoparticle (NP)-based vaccine carrier, functionalized with CpG and viral peptides is able to efficiently reactivate the CD8+ T cell response and improve the eradication of virus infected cells. However, the mechanisms underlying this effect were largely unclear. While type I interferons (IFNs I) are considered to drive T cell exhaustion by persistent immune activation during chronic viral infection, we here describe an indispensable role of IFN I induced by therapeutic vaccination to efficiently reinforce cytotoxic CD8+ T cells (CTL) and improve control of chronic retroviral infection. The induction of IFN I is CpG dependent and leads to significant IFN signaling indicated by upregulation of IFN stimulated genes. By vaccinating chronically retrovirus-infected mice lacking the IFN I receptor (IFNAR−/−) or by blocking IFN I signaling in vivo during therapeutic vaccination, we demonstrate that IFN I signaling is necessary to drive full reactivation of CTLs. Surprisingly, we also identified an impaired suppressive capability of regulatory T cells in the presence of IFNα, which implicates an important role for vaccine-induced IFNα in the regulation of the T cell response during chronic retroviral infection. Our data suggest that inducing IFN I signaling in conjunction with the presentation of viral antigens can reactivate immune functions and reduce viral loads in chronic infections. Therefore, we propose CaP NPs as potential therapeutic tool to treat chronic infections.
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Affiliation(s)
- Torben Knuschke
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Olga Rotan
- Institute of Inorganic Chemistry, Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Essen, Germany
| | - Wibke Bayer
- Institute of Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Sebastian Kollenda
- Institute of Inorganic Chemistry, Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Essen, Germany
| | - Julia Dickow
- Institute of Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Kathrin Sutter
- Institute of Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Wiebke Hansen
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Ulf Dittmer
- Institute of Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Karl S Lang
- Institute for Immunology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Matthias Epple
- Institute of Inorganic Chemistry, Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Essen, Germany
| | - Jan Buer
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Astrid M Westendorf
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
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Kopp M, Rotan O, Papadopoulos C, Schulze N, Meyer H, Epple M. Delivery of the autofluorescent protein R-phycoerythrin by calcium phosphate nanoparticles into four different eukaryotic cell lines (HeLa, HEK293T, MG-63, MC3T3): Highly efficient, but leading to endolysosomal proteolysis in HeLa and MC3T3 cells. PLoS One 2017; 12:e0178260. [PMID: 28586345 PMCID: PMC5460861 DOI: 10.1371/journal.pone.0178260] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Accepted: 04/27/2017] [Indexed: 02/07/2023] Open
Abstract
Nanoparticles can be used as carriers to transport biomolecules like proteins and synthetic molecules across the cell membrane because many molecules are not able to cross the cell membrane on their own. The uptake of nanoparticles together with their cargo typically occurs via endocytosis, raising concerns about the possible degradation of the cargo in the endolysosomal system. As the tracking of a dye-labelled protein during cellular uptake and processing is not indicative of the presence of the protein itself but only for the fluorescent label, a label-free tracking was performed with the red-fluorescing model protein R-phycoerythrin (R-PE). Four different eukaryotic cell lines were investigated: HeLa, HEK293T, MG-63, and MC3T3. Alone, the protein was not taken up by any cell line; only with the help of calcium phosphate nanoparticles, an efficient uptake occurred. After the uptake into HeLa cells, the protein was found in early endosomes (shown by the marker EEA1) and lysosomes (shown by the marker Lamp1). There, it was still intact and functional (i.e. properly folded) as its red fluorescence was detected. However, a few hours after the uptake, proteolysis started as indicated by the decreasing red fluorescence intensity in the case of HeLa and MC3T3 cells. 12 h after the uptake, the protein was almost completely degraded in HeLa cells and MC3T3 cells. In HEK293T cells and MG-63 cells, no degradation of the protein was observed. In the presence of Bafilomycin A1, an inhibitor of acidification and protein degradation in lysosomes, the fluorescence of R-PE remained intact over the whole observation period in the four cell lines. These results indicate that despite an efficient nanoparticle-mediated uptake of proteins by cells, a rapid endolysosomal degradation may prevent the desired (e.g. therapeutic) effect of a protein inside a cell.
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Affiliation(s)
- Mathis Kopp
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Essen, Germany
| | - Olga Rotan
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Essen, Germany
| | | | - Nina Schulze
- Imaging Centre Campus Essen (ICCE), University of Duisburg-Essen, Essen, Germany
| | - Hemmo Meyer
- Centre for Medical Biotechnology, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
| | - Matthias Epple
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Essen, Germany
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Rotan O, Severin KN, Pöpsel S, Peetsch A, Merdanovic M, Ehrmann M, Epple M. Uptake of the proteins HTRA1 and HTRA2 by cells mediated by calcium phosphate nanoparticles. Beilstein J Nanotechnol 2017; 8:381-393. [PMID: 28326227 PMCID: PMC5331334 DOI: 10.3762/bjnano.8.40] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 01/22/2017] [Indexed: 06/06/2023]
Abstract
The efficient intracellular delivery of (bio)molecules into living cells remains a challenge in biomedicine. Many biomolecules and synthetic drugs are not able to cross the cell membrane, which is a problem if an intracellular mode of action is desired, for example, with a nuclear receptor. Calcium phosphate nanoparticles can serve as carriers for small and large biomolecules as well as for synthetic compounds. The nanoparticles were prepared and colloidally stabilized with either polyethyleneimine (PEI; cationic nanoparticles) or carboxymethyl cellulose (CMC; anionic nanoparticles) and loaded with defined amounts of the fluorescently labelled proteins HTRA1, HTRA2, and BSA. The nanoparticles were purified by ultracentrifugation and characterized by dynamic light scattering and scanning electron microscopy. Various cell types (HeLa, MG-63, THP-1, and hMSC) were incubated with fluorescently labelled proteins alone or with protein-loaded cationic and anionic nanoparticles. The cellular uptake was followed by light and fluorescence microscopy, confocal laser scanning microscopy (CLSM), and flow cytometry. All proteins were readily transported into the cells by cationic calcium phosphate nanoparticles. Notably, only HTRA1 was able to penetrate the cell membrane of MG-63 cells in dissolved form. However, the application of endocytosis inhibitors revealed that the uptake pathway was different for dissolved HTRA1 and HTRA1-loaded nanoparticles.
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Affiliation(s)
- Olga Rotan
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Universitaetsstr. 5-7, D-45117 Essen, Germany
| | - Katharina N Severin
- Centre for Medical Biotechnology, Faculty of Biology, University of Duisburg-Essen, Universitaetsstr. 5-7, D-45117 Essen, Germany
| | - Simon Pöpsel
- Centre for Medical Biotechnology, Faculty of Biology, University of Duisburg-Essen, Universitaetsstr. 5-7, D-45117 Essen, Germany
| | - Alexander Peetsch
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Universitaetsstr. 5-7, D-45117 Essen, Germany
| | - Melisa Merdanovic
- Centre for Medical Biotechnology, Faculty of Biology, University of Duisburg-Essen, Universitaetsstr. 5-7, D-45117 Essen, Germany
| | - Michael Ehrmann
- Centre for Medical Biotechnology, Faculty of Biology, University of Duisburg-Essen, Universitaetsstr. 5-7, D-45117 Essen, Germany
| | - Matthias Epple
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Universitaetsstr. 5-7, D-45117 Essen, Germany
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Tenkumo T, Vanegas Sáenz JR, Takada Y, Takahashi M, Rotan O, Sokolova V, Epple M, Sasaki K. Gene transfection of human mesenchymal stem cells with a nano-hydroxyapatite-collagen scaffold containing DNA-functionalized calcium phosphate nanoparticles. Genes Cells 2016; 21:682-95. [DOI: 10.1111/gtc.12374] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 04/13/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Taichi Tenkumo
- Liaison Center for Innovative Dentistry; Tohoku University Graduate School of Dentistry; 4-1 Seiryo-machi Aoba-ku Sendai 980-8575 Japan
| | - Juan Ramón Vanegas Sáenz
- Division of Advanced Prosthetic Dentistry; Tohoku University Graduate school of Dentistry; 4-1 Seiryo-machi Aoba-ku Sendai 980-8575 Japan
| | - Yukyo Takada
- Division of Dental Biomaterials; Tohoku University Graduate School of Dentistry; 4-1 Seiryo-machi Aoba-ku Sendai 980-8575 Japan
| | - Masatoshi Takahashi
- Division of Dental Biomaterials; Tohoku University Graduate School of Dentistry; 4-1 Seiryo-machi Aoba-ku Sendai 980-8575 Japan
| | - Olga Rotan
- Institute of Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE); University of Duisburg-Essen; Universitätsstraße 5-7 Essen D-45117 Germany
| | - Viktoriya Sokolova
- Institute of Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE); University of Duisburg-Essen; Universitätsstraße 5-7 Essen D-45117 Germany
| | - Matthias Epple
- Institute of Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE); University of Duisburg-Essen; Universitätsstraße 5-7 Essen D-45117 Germany
| | - Keiichi Sasaki
- Liaison Center for Innovative Dentistry; Tohoku University Graduate School of Dentistry; 4-1 Seiryo-machi Aoba-ku Sendai 980-8575 Japan
- Division of Advanced Prosthetic Dentistry; Tohoku University Graduate school of Dentistry; 4-1 Seiryo-machi Aoba-ku Sendai 980-8575 Japan
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Knuschke T, Rotan O, Bayer W, Sokolova V, Hansen W, Sparwasser T, Dittmer U, Epple M, Buer J, Westendorf AM. Combination of nanoparticle-based therapeutic vaccination and transient ablation of regulatory T cells enhances anti-viral immunity during chronic retroviral infection. Retrovirology 2016; 13:24. [PMID: 27076190 PMCID: PMC4831142 DOI: 10.1186/s12977-016-0258-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 03/28/2016] [Indexed: 02/05/2023] Open
Abstract
Background Regulatory T cells (Tregs) have been shown to limit anti-viral immunity during chronic retroviral infection and to restrict vaccine-induced T cell responses. The objective of the study was to assess whether a combinational therapy of nanoparticle-based therapeutic vaccination and concomitant transient ablation of Tregs augments anti-viral immunity and improves virus control in chronically retrovirus-infected mice. Therefore, chronically Friend retrovirus (FV)-infected mice were immunized with calcium phosphate (CaP) nanoparticles functionalized with TLR9 ligand CpG and CD8+ or CD4+ T cell epitope peptides (GagL85–93 or Env gp70123–141) of FV. In addition, Tregs were ablated during the immunization process. Reactivation of CD4+ and CD8+ effector T cells was analysed and the viral loads were determined. Results Therapeutic vaccination of chronically FV-infected mice with functionalized CaP nanoparticles transiently reactivated cytotoxic CD8+ T cells and significantly reduced the viral loads. Transient ablation of Tregs during nanoparticle-based therapeutic vaccination strongly enhanced anti-viral immunity and further decreased viral burden. Conclusion Our data illustrate a crucial role for CD4+ Foxp3+ Tregs in the suppression of anti-viral T cell responses during therapeutic vaccination against chronic retroviral infection. Thus, the combination of transient Treg ablation and therapeutic nanoparticle-based vaccination confers robust and sustained anti-viral immunity. Electronic supplementary material The online version of this article (doi:10.1186/s12977-016-0258-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Torben Knuschke
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, 45122, Essen, Germany
| | - Olga Rotan
- Institute of Inorganic Chemistry and Center for Nanointegration (CeNIDE), University of Duisburg-Essen, 45141, Essen, Germany
| | - Wibke Bayer
- Institute of Virology, University Hospital Essen, University of Duisburg-Essen, 45122, Essen, Germany
| | - Viktoriya Sokolova
- Institute of Inorganic Chemistry and Center for Nanointegration (CeNIDE), University of Duisburg-Essen, 45141, Essen, Germany
| | - Wiebke Hansen
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, 45122, Essen, Germany
| | - Tim Sparwasser
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Medicine, 30625, Hannover, Germany
| | - Ulf Dittmer
- Institute of Virology, University Hospital Essen, University of Duisburg-Essen, 45122, Essen, Germany
| | - Matthias Epple
- Institute of Inorganic Chemistry and Center for Nanointegration (CeNIDE), University of Duisburg-Essen, 45141, Essen, Germany
| | - Jan Buer
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, 45122, Essen, Germany
| | - Astrid M Westendorf
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, 45122, Essen, Germany.
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Neuhaus B, Tosun B, Rotan O, Frede A, Westendorf AM, Epple M. Nanoparticles as transfection agents: a comprehensive study with ten different cell lines. RSC Adv 2016. [DOI: 10.1039/c5ra25333k] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The performance of transfection agents to deliver nucleic acids into cells strongly depends on the cell type.
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Affiliation(s)
- Bernhard Neuhaus
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE)
- University of Duisburg-Essen
- 45117 Essen
- Germany
| | - Benjamin Tosun
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE)
- University of Duisburg-Essen
- 45117 Essen
- Germany
| | - Olga Rotan
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE)
- University of Duisburg-Essen
- 45117 Essen
- Germany
| | - Annika Frede
- Institute of Medical Microbiology
- University Hospital Essen
- University of Duisburg-Essen
- Essen
- Germany
| | - Astrid M. Westendorf
- Institute of Medical Microbiology
- University Hospital Essen
- University of Duisburg-Essen
- Essen
- Germany
| | - Matthias Epple
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE)
- University of Duisburg-Essen
- 45117 Essen
- Germany
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Range S, Hagmeyer D, Rotan O, Sokolova V, Verheyen J, Siebers B, Epple M. A continuous method to prepare poorly crystalline silver-doped calcium phosphate ceramics with antibacterial properties. RSC Adv 2015. [DOI: 10.1039/c5ra00401b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Silver-doped calcium phosphate ceramics were prepared in discontinuous and continuous processes with different amounts of incorporated silver (up to 1.8 wt% silver).
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Affiliation(s)
- S. Range
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE)
- University of Duisburg-Essen
- 45117 Essen
- Germany
| | - D. Hagmeyer
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE)
- University of Duisburg-Essen
- 45117 Essen
- Germany
| | - O. Rotan
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE)
- University of Duisburg-Essen
- 45117 Essen
- Germany
| | - V. Sokolova
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE)
- University of Duisburg-Essen
- 45117 Essen
- Germany
| | - J. Verheyen
- Biofilm Centre Molecular Enzyme Technology and Biochemistry
- University of Duisburg-Essen
- 45117 Essen
- Germany
| | - B. Siebers
- Biofilm Centre Molecular Enzyme Technology and Biochemistry
- University of Duisburg-Essen
- 45117 Essen
- Germany
| | - M. Epple
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE)
- University of Duisburg-Essen
- 45117 Essen
- Germany
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Knuschke T, Bayer W, Rotan O, Sokolova V, Wadwa M, Kirschning CJ, Hansen W, Dittmer U, Epple M, Buer J, Westendorf AM. Prophylactic and therapeutic vaccination with a nanoparticle-based peptide vaccine induces efficient protective immunity during acute and chronic retroviral infection. Nanomedicine: Nanotechnology, Biology and Medicine 2014; 10:1787-98. [DOI: 10.1016/j.nano.2014.06.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 06/13/2014] [Indexed: 01/31/2023]
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Ruesing J, Rotan O, Gross-Heitfeld C, Mayer C, Epple M. Nanocapsules of a cationic polyelectrolyte and nucleic acid for efficient cellular uptake and gene transfer. J Mater Chem B 2014; 2:4625-4630. [DOI: 10.1039/c4tb00392f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Knuschke T, Sokolova V, Rotan O, Wadwa M, Tenbusch M, Hansen W, Staeheli P, Epple M, Buer J, Westendorf AM. Immunization with Biodegradable Nanoparticles Efficiently Induces Cellular Immunity and Protects against Influenza Virus Infection. J I 2013; 190:6221-9. [DOI: 10.4049/jimmunol.1202654] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Sokolova V, Ludwig AK, Hornung S, Rotan O, Horn PA, Epple M, Giebel B. Characterisation of exosomes derived from human cells by nanoparticle tracking analysis and scanning electron microscopy. Colloids Surf B Biointerfaces 2011; 87:146-50. [PMID: 21640565 DOI: 10.1016/j.colsurfb.2011.05.013] [Citation(s) in RCA: 559] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 05/02/2011] [Accepted: 05/05/2011] [Indexed: 12/20/2022]
Abstract
Exosomes from three different cell types (HEK 293T, ECFC, MSC) were characterised by scanning electron microscopy (SEM), dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA). The diameter was around 110 nm for the three cell types. The stability of exosomes was examined during storage at -20°C, 4°C, and 37°C. The size of the exosomes decreased at 4°C and 37°C, indicating a structural change or degradation. Multiple freezing to -20°C and thawing did not affect the exosome size. Multiple ultracentrifugation also did not change the exosome size.
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Affiliation(s)
- Viktoriya Sokolova
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany
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