Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Engineered core-shell nanoparticles for biomedical applications
KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
2010 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

The necessity for synthesis of nanoparticles with well controlled size and morphology emerged with the development in recent years of novel advanced applications especially in biomedical related fields. These applications require nanoparticles with more complex architecture such as multifunctional nanoparticles (i.e. core–shell structures) that can carry several components with different embedded functionalities. In this thesis, we developed core–shell nanoparticles (CSNPs) with finely tuned silica shell on iron oxide core as model system for advanced applications in nanomedicine such as MRI, drug delivery and hyperthermia.

The synthesis of monodispersed, and well separated, single iron oxide core–silica (SiO2) shell nanoparticles for biomedical applications is still a challenge. Substantial amount of aggregated and multicore CSNPs are generally the undesired outcome. In this thesis, synthesis of monodispersed, free of necking, single core iron oxide-SiO2 different distinct overall size and tuneable shell thickness was performed using an inverse microemulsion method. The influence of the reaction time, hydrodynamic conditions and precursor concentration on the synthesis process and thickness of the silica layer was investigated and the process was optimised. The residual reactions during the post synthesis processing were inhibited using a combination of pH adjustment and alternating shock freezing with ultracentrifuging.

The second part of the thesis is concerning thorough characterisation of the CSNPs with different shell thickness. The non-aggregated tuneable shell CSNPs maintained the superparamagnetic character of the cores with high magnetisation, showing great potential for their applications in nanomedicine. Magnetic measurements and relaxivity tests were performed and the comparison of the CSNPs with commercial products revealed the fact that relaxation time ratios (r2/r1) obtained are higher than those of the commercially available MRI contrast agents which indicates a better T2 contrast.

In the last part of the thesis the in-vitro toxicity investigation results are reported. For the investigation of cytotoxicity (3- 4, 5-dimethyldiazol-2-yl)-2, 5 diphenyl-tetrazolium bromide (MTT) assay was performed and the secretion of pro-inflammatory cytokines TNF-α and IL-6 was determined using enzyme-linked immunosorbent assay (ELISA). The cells were exposed to a wide range of concentrations of nanoparticles (between 0.5 μg/ml to 100 μg/ml). The cell toxicity results indicated no severe toxic effects on human monocyte-derived macrophages (HMDM) as model system. The internalisation of the nanoparticles by HMDM was monitored using transmission electron microscopy (TEM).

The CSNPs have the capacity of forming stable colloidal dispersions at physiological pH, with desired magnetic properties, low toxicity, and the potential for further functionalisation via surface modification of the silica shell or by adding new components (i.e. quantum dots, therapeutics). These characteristics make them highly promising for drug delivery, medical imaging, hyperthermia, magnetic cell marking and cell separation as well as many other biomedical applications.

 

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology , 2010. , viii, 59 p.
Series
Trita-ICT/MAP AVH, ISSN 1653-7610 ; 2010:02
National Category
Other Materials Engineering
Identifiers
URN: urn:nbn:se:kth:diva-12708ISBN: 978-91-7415-558-4 OAI: oai:DiVA.org:kth-12708DiVA: diva2:318171
Presentation
2010-04-09, Sal C2, Electrum, Isafjordsgatan 22, Kista, 10:30 (English)
Opponent
Supervisors
Note
QC 20100506Available from: 2010-05-06 Created: 2010-05-06 Last updated: 2011-04-15Bibliographically approved
List of papers
1. Optimised Synthetic Route for Tuneable Shell SiO2@Fe3O4 Core-Shell Nanoparticles
Open this publication in new window or tab >>Optimised Synthetic Route for Tuneable Shell SiO2@Fe3O4 Core-Shell Nanoparticles
Show others...
2009 (English)In: Materials Research Society Symposium Proceedings, 2009, Vol. 1140, 209-214 p.Conference paper, Published paper (Other academic)
Abstract [en]

Multifunctional nanoparticles (that have in their structure different components that can perform various functions) are subject of intensive research activities as they find a large variety of applications in numerous biomedical fields from enhancement of image contrast in MRI to different magnetically controllable drug delivery systems. In this study we report on the synthesis of well-separated, monodisperse single coreshell SiO2@Fe3O4 nanoparticles with an overall diameter of ~30 nm. The influence of stirring rate and reaction time on synthesis of tuneable shell thickness core-shell nanoparticles is reported. Particles’ cell toxicity and performance as MRI contrast agents were also studied due to their promising biological applications (as contrast agents, cell labelling and separation, drug delivery systems, etc.) and results are promising in terms of MRI performance as well as having no significant cytotoxicity.

 

Series
Materials Research Society Symposium Proceedings, ISSN 0272-9172
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:kth:diva-12700 (URN)000273377400032 ()
Note
QC 20100506Available from: 2010-05-06 Created: 2010-05-06 Last updated: 2011-04-15Bibliographically approved
2. High quality and tuneable silica shell-magnetic core nanoparticles
Open this publication in new window or tab >>High quality and tuneable silica shell-magnetic core nanoparticles
Show others...
2010 (English)In: Journal of nanoparticle research, ISSN 1388-0764, E-ISSN 1572-896X, Vol. 12, no 4, 1137-1147 p.Article in journal (Refereed) Published
Abstract [en]

Obtaining small (<50 nm), monodispersed, well-separated, single iron oxide core-silica SiO2) shell nanoparticles for biomedical applications is still a challenge. Preferably, they are synthesized by inverse microemulsion method. However, substantial amount of aggregated and multicore core- shell nanoparticles is the undesired outcome of the method. In this study, we report on the production of less than 50 nm overall size, monodispersed, free of necking, single core iron oxide-SiO2 shell nanoparticles with tuneable shell thickness by a carefully optimized inverse microemulsion method. The high degree of control over the process is achieved by understanding the mechanism of core-shell nanoparticles formation. By varying the reaction time and recursor concentration, the thickness of silica layer an the core nanoparticles can be finely adjusted from to 13 nm. Residual reactions during the workup were inhibited by a combination of pH control with hock freezing and ultracentrifuging. These highquality tuneable core-shell nanocomposite particles exhibit superparamagnetic character and sufficiently high magnetization with great potential for biomedical applications (e.g. MRI, cell separation and magnetically driven drug delivery systems) either as-prepared or by additional surface modification for improved biocompatibility.

Keyword
Core-shell, Inverse microemulsion, Nanomedicine, Nanoparticle, Non-aggregated, Silica, Superparamagnetism
National Category
Social Sciences Interdisciplinary
Identifiers
urn:nbn:se:kth:diva-12703 (URN)10.1007/s11051-009-9661-7 (DOI)000276883600007 ()2-s2.0-77955086109 (Scopus ID)
Funder
EU, FP7, Seventh Framework ProgrammeKnut and Alice Wallenberg Foundation, UAW2004.0224
Note
QC 20110415Available from: 2010-05-06 Created: 2010-05-06 Last updated: 2017-12-12Bibliographically approved
3. Biocompatibility of tuneable silica shell-magnetic core nanoparticles evaluated in vitro using primary human monocute-derived macrophages
Open this publication in new window or tab >>Biocompatibility of tuneable silica shell-magnetic core nanoparticles evaluated in vitro using primary human monocute-derived macrophages
Show others...
(English)Manuscript (preprint) (Other (popular science, discussion, etc.))
Keyword
superparamagnetic nanoparticles, core-shell, biocompatibility, macrophages, cytokines, silica
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:kth:diva-12704 (URN)
Note
QC 20100506Available from: 2010-05-06 Created: 2010-05-06 Last updated: 2011-04-15Bibliographically approved

Open Access in DiVA

fulltext(4061 kB)1677 downloads
File information
File name FULLTEXT02.pdfFile size 4061 kBChecksum SHA-512
8efc7cb6b8c556bccc4612068f598ffd3f65ed9d1b7d579cb7ce617877973f30cdb4eac387841f918d19f7da207566a4d74aeceb6f3c84917921dbc165e7c44e
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Vogt, Carmen Mihaela
By organisation
Functional Materials, FNM
Other Materials Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 1677 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 600 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf