BECAS
VALDÉS Daniela Paola
congresos y reuniones científicas
Título:
In situ formation and thermographical analysis of nanoparticle chain-like arrangements in polyacrylamide phantom during hyperthermia experiments
Autor/es:
DANIELA P. VALDÉS; TEOBALDO E. TORRES; ANA C. MALDONADO; MARCELA S. NADAL; EMILIO DE BIASI; ROBERTO D. ZYSLER; GERARDO F. GOYA; ENIO LIMA JR.
Lugar:
Svetlogorsk
Reunión:
Conferencia; IV International Baltic Conference on Magnetism 2021 - IBCM 2021; 2021
Resumen:
The formation and control of magneticnanoparticle (MNP) arrangements during the hyperthermia experiment (HE) forviscosities similar to those of the intracellular environment is relevant forthe enhancement of the specific power absorption [1]. A gel with adjustableviscosity such as polyacrylamide gel may work as a phantom to emulateintracellular viscosity [2].In this work,γ-Fe2O3 MNPs with 25 nm diameter(σ = 7 nm) were prepared through the thermal decomposition method with asubsequent annealing. We determined the saturation magnetization (MS= 68 emu g−1 at room temperature), the mean blocking temperature (<TB>∼ 10 K) and the effective anisotropyconstant (K ∼ 1 ×104 erg cm−3).The hydrophobic character of the as-synthesized nanoparticles was changed tohydrophilic by a post-synthesis glucose coating. Two typesof 4% polyacrylamide gel phantoms with dispersed MNPs were prepared: one conventionallyjellified (dispersed MNPs) and another one jellified during the HE with an ac field with amplitude H0 =200 Oe and frequency f = 630 kHz, each one at MNP concentrations of 0.1 and 0.5% wt. Images were taken with a cryo-focused electron and ion beam (Cryo-FIB-SEM)microscope, where the formation of chains-like structures was confirmed forgels exposed to the ac field (see Figure 1). Power absorption experiments were performedunder ac magnetic fields with amplitude H0 = 550 Oe and frequency f= 400 kHz. The temperature evolution was monitored through a thermographic cameraand spatio-temporal profiles were obtained from the videos. Qualitative andquantitative differences were observed between the gel phantoms.To conclude, we obtained considerabletemperature increments for MNPs dispersed in cytosol-viscosity emulating mediumand confirmed the formation of chain-like arrangements for samples jellified insitu in the HE, which is of great importance to optimize the application incells. [1]D.P. Valdés, Phys. Rev. Applied 14, 014023 (2020)[2] T. Yano, Biosci. Biotechnol. Biochem. 57, 528 (1993)@font-face{font-family:"Cambria Math";panose-1:2 4 5 3 5 4 6 3 2 4;mso-font-charset:0;mso-generic-font-family:roman;mso-font-pitch:variable;mso-font-signature:-536870145 1107305727 0 0 415 0;}@font-face{font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;mso-font-charset:0;mso-generic-font-family:swiss;mso-font-pitch:variable;mso-font-signature:-469750017 -1073732485 9 0 511 0;}@font-face{font-family:Times;panose-1:0 0 5 0 0 0 0 2 0 0;mso-font-alt:&#65021;&#65021;&#65021;&#65021;&#65021;&#65021;&#65021;&#65021;&#285;&#1932;;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:-536870145 1342185562 0 0 415 0;}p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-qformat:yes;mso-style-parent:"";margin:0cm;mso-pagination:widow-orphan;font-size:12.0pt;font-family:"Times New Roman",serif;mso-fareast-font-family:"Times New Roman";}p.MsoHeader, li.MsoHeader, div.MsoHeader{mso-style-unhide:no;mso-style-link:"Header Char";margin:0cm;mso-pagination:widow-orphan;mso-hyphenate:none;tab-stops:center 207.65pt right 415.3pt;font-size:12.0pt;font-family:"Times New Roman",serif;mso-fareast-font-family:"Times New Roman";mso-ansi-language:SK;mso-fareast-language:ZH-CN;}p.MsoFooter, li.MsoFooter, div.MsoFooter{mso-style-unhide:no;mso-style-link:"Footer Char";margin:0cm;mso-pagination:widow-orphan;mso-hyphenate:none;tab-stops:center 207.65pt right 415.3pt;font-size:12.0pt;font-family:"Times New Roman",serif;mso-fareast-font-family:"Times New Roman";mso-ansi-language:SK;mso-fareast-language:ZH-CN;}p.MsoCaption, li.MsoCaption, div.MsoCaption{mso-style-priority:35;mso-style-qformat:yes;mso-style-next:Normal;margin-top:0cm;margin-right:0cm;margin-bottom:10.0pt;margin-left:0cm;mso-pagination:widow-orphan;font-size:9.0pt;font-family:"Calibri",sans-serif;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;color:#1F497D;mso-themecolor:text2;mso-ansi-language:RU;font-style:italic;}p{mso-style-priority:99;mso-margin-top-alt:auto;margin-right:0cm;mso-margin-bottom-alt:auto;margin-left:0cm;mso-pagination:widow-orphan;font-size:12.0pt;font-family:"Times New Roman",serif;mso-fareast-font-family:"Times New Roman";}span.HeaderChar{mso-style-name:"Header Char";mso-style-unhide:no;mso-style-locked:yes;mso-style-link:Header;mso-ansi-font-size:12.0pt;mso-bidi-font-size:12.0pt;font-family:"Times New Roman",serif;mso-ascii-font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman";mso-bidi-font-family:"Times New Roman";mso-ansi-language:SK;mso-fareast-language:ZH-CN;}span.FooterChar{mso-style-name:"Footer Char";mso-style-unhide:no;mso-style-locked:yes;mso-style-link:Footer;mso-ansi-font-size:12.0pt;mso-bidi-font-size:12.0pt;font-family:"Times New Roman",serif;mso-ascii-font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman";mso-bidi-font-family:"Times New Roman";mso-ansi-language:SK;mso-fareast-language:ZH-CN;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-size:11.0pt;mso-ansi-font-size:11.0pt;mso-bidi-font-size:11.0pt;font-family:"Calibri",sans-serif;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;mso-ansi-language:RU;}.MsoPapDefault{mso-style-type:export-only;margin-bottom:10.0pt;line-height:115%;}div.WordSection1{page:WordSection1;}