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Rocha, Igor
Publications (10 of 16) Show all publications
Rocha, I., Lindh, J., Hong, J., Strömme, M., Mihranyan, A. & Ferraz, N. (2018). Blood Compatibility of Sulfonated Cladophora Nanocellulose Beads. Molecules, 23(3), Article ID 601.
Open this publication in new window or tab >>Blood Compatibility of Sulfonated Cladophora Nanocellulose Beads
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2018 (English)In: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 23, no 3, article id 601Article in journal (Refereed) Published
Abstract [en]

Sulfonated cellulose beads were prepared by oxidation of Cladophora nanocellulose to 2,3-dialdehyde cellulose followed by sulfonation using bisulfite. The physicochemical properties of the sulfonated beads, i.e., high surface area, high degree of oxidation, spherical shape, and the possibility of tailoring the porosity, make them interesting candidates for the development of immunosorbent platforms, including their application in extracorporeal blood treatments. A desired property for materials used in such applications is blood compatibility; therefore in the present work, we investigate the hemocompatibility of the sulfonated cellulose beads using an in vitro whole blood model. Complement system activation (C3a and sC5b-9 levels), coagulation activation (thrombin-antithrombin (TAT) levels) and hemolysis were evaluated after whole blood contact with the sulfonated beads and the results were compared with the values obtained with the unmodified Cladophora nanocellulose. Results showed that neither of the cellulosic materials presented hemolytic activity. A marked decrease in TAT levels was observed after blood contact with the sulfonated beads, compared with Cladophora nanocellulose. However, the chemical modification did not promote an improvement in Cladophora nanocellulose hemocompatibility in terms of complement system activation. Even though the sulfonated beads presented a significant reduction in pro-coagulant activity compared with the unmodified material, further modification strategies need to be investigated to control the complement activation by the cellulosic materials.

Keywords
sulfonated beads; Cladophora nanocellulose; hemocompatibility; coagulation; complement system
National Category
Nano Technology
Identifiers
urn:nbn:se:uu:diva-346209 (URN)10.3390/molecules23030601 (DOI)000428514100092 ()
Funder
Knut and Alice Wallenberg Foundation
Available from: 2018-03-15 Created: 2018-03-15 Last updated: 2019-06-28Bibliographically approved
Rocha, I., Ferraz, N., Mihranyan, A., Strömme, M. & Lindh, J. (2018). Hemocompatibility of porous sulfonated Cladophora cellulose beads towards a blood purification material with anticoagulant properties. Paper presented at 255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, MAR 18-22, 2018, New Orleans, LA, USA. Abstract of Papers of the American Chemical Society, 255
Open this publication in new window or tab >>Hemocompatibility of porous sulfonated Cladophora cellulose beads towards a blood purification material with anticoagulant properties
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2018 (English)In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2018
National Category
Nano Technology
Research subject
Engineering Science with specialization in Nanotechnology and Functional Materials
Identifiers
urn:nbn:se:uu:diva-365865 (URN)000435537703062 ()
Conference
255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, MAR 18-22, 2018, New Orleans, LA, USA
Available from: 2018-11-20 Created: 2018-11-20 Last updated: 2018-11-20Bibliographically approved
Hattori, Y., Abdellah, M., Rocha, I., Pavliuk, M. V., Fernandes, D. L. A. & Sá, J. (2018). Light-induced ultrafast proton-coupled electron transfer responsible for H-2 evolution on silver plasmonics. Materials Today, 21(6), 590-593
Open this publication in new window or tab >>Light-induced ultrafast proton-coupled electron transfer responsible for H-2 evolution on silver plasmonics
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2018 (English)In: Materials Today, ISSN 1369-7021, E-ISSN 1873-4103, Vol. 21, no 6, p. 590-593Article in journal (Refereed) Published
Abstract [en]

Light-driven proton-coupled electron transfer (PCET) reactions on nanoplasmonics would bring temporal control of their reactive pathways, in particular, prolong their charge separation state. Using a silver nano-hybrid plasmonic structure, we observed that optical excitation of Ag-localized surface plasmon instigated electron injection into TiO2 conduction band and oxidation of isopropanol alcoholic functionality. Femtosecond transient infrared absorption studies show that electron transfer from Ag to TiO2 occurs in ca. 650 fs, while IPA molecules near the Ag surface undergo an ultrafast bidirectional PCET step within 400 fs. Our work demonstrates that ultrafast PCET reaction plays a determinant role in prolonging charge separation state, providing an innovative strategy for visible-light photocatalysis with plasmonic nanostructures.

Place, publisher, year, edition, pages
ELSEVIER SCI LTD, 2018
National Category
Physical Chemistry Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-362849 (URN)10.1016/j.mattod.2018.05.002 (DOI)000441765700016 ()
Funder
Swedish Research Council, 2015-03764Stiftelsen Olle Engkvist Byggmästare, 2016/367
Available from: 2018-10-15 Created: 2018-10-15 Last updated: 2018-10-18Bibliographically approved
Rocha, I., Hattori, Y., Mirna, D., Mihranyan, A., Strömme, M. & Lindh, J. (2018). Spectroscopic and physicochemical characterization of sulfonated Cladophora cellulose beads. Langmuir, 34(37), 11121-11125
Open this publication in new window or tab >>Spectroscopic and physicochemical characterization of sulfonated Cladophora cellulose beads
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2018 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 34, no 37, p. 11121-11125Article in journal (Refereed) Published
Abstract [en]

The work presents a full physicochemical characterization of sulfonated cellulose beads prepared from Cladophora nanocellulose intended for use in biological systems. 2,3-Dialdehyde cellulose (DAC) beads were sulfonated, and transformation of up to 50% of the aldehyde groups was achieved, resulting in highly charged and porous materials compared to the compact surface of the DAC beads. The porosity could be tailored by adjusting the degree of sulfonation, and a subsequent reduction of the aldehyde groups to hydroxyl groups maintained the bead structure without considerable alteration of the surface properties. The thermal stability of the DAC beads was significantly increased with the sulfonation and reduction reactions. Raman spectroscopy also showed to be a useful technique for the characterization of sulfonated cellulose materials.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Physical Chemistry Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-346211 (URN)10.1021/acs.langmuir.8b01704 (DOI)000445440200035 ()30169040 (PubMedID)
Available from: 2018-03-15 Created: 2018-03-15 Last updated: 2018-10-19Bibliographically approved
Rocha, I., Ferraz, N., Mihranyan, A., Strömme, M. & Lindh, J. (2018). Sulfonated Nanocellulose Beads as Potential Immunosorbents. Cellulose (London), 28(3), 1899-1910
Open this publication in new window or tab >>Sulfonated Nanocellulose Beads as Potential Immunosorbents
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2018 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 28, no 3, p. 1899-1910Article in journal (Refereed) Published
Abstract [en]

Herein 2,3-dialdehyde cellulose beads prepared from Cladophora green algae nanocellulose were sulfonated and characterized by FTIR, conductometric titration, elemental analysis, SEM, ζ-potential, nitrogen adsorption–desorption and laser diffraction, aiming for its application as a potential immunosorbent material. Porous beads were prepared at mild reaction conditions in water and were chemically modified by sulfonation and reduction. The obtained 15 µm sized sulfonated beads were found to be highly charged and to have a high surface area of ~ 100 m2 g−1 and pore sizes between 20 and 60 nm, adequate for usage as immunosorbents. After reduction of remaining aldehyde groups, the beads could be classified as non-cytotoxic in indirect toxicity studies with human dermal fibroblasts as a first screening of their biocompatibility. The observed properties make the sulfonated cellulose beads interesting for further development as matrix material in immunosorbent devices.

Keywords
Periodate oxidation Dialdehyde cellulose, Surface group density, Sulfonated beads, Cytotoxicity
National Category
Nano Technology
Identifiers
urn:nbn:se:uu:diva-346207 (URN)10.1007/s10570-018-1661-2 (DOI)000427379200027 ()
Funder
Knut and Alice Wallenberg Foundation
Available from: 2018-03-15 Created: 2018-03-15 Last updated: 2018-05-18Bibliographically approved
Pavliuk, M. V., Fernandes, A. B., Abdellah, M., Fernandes, D. L. A., Machado, C. ., Rocha, I., . . . Sá, J. (2017). Nano-hybrid plasmonic photocatalyst for hydrogen production at 20% efficiency. Scientific Reports, 7, Article ID 8670.
Open this publication in new window or tab >>Nano-hybrid plasmonic photocatalyst for hydrogen production at 20% efficiency
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2017 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 8670Article in journal (Refereed) Published
Abstract [en]

The efficient conversion of light energy into chemical energy is key for sustainable human development. Several photocatalytic systems based on photovoltaic electrolysis have been used to produce hydrogen via water reduction. However, in such devices, light harvesting and proton reduction are carried separately, showing quantum efficiency of about 10–12%. Here, we report a nano-hybrid photocatalytic assembly that enables concomitant reductive hydrogen production and pollutant oxidation with solar-to-fuel efficiencies up to 20%. The modular architecture of this plasmonic material allows the fine-tuning of its photocatalytic properties by simple manipulation of a reduced number of basic components.

National Category
Nano Technology
Research subject
Engineering Science with specialization in Nanotechnology and Functional Materials; Engineering Science with specialization in Nanotechnology and Functional Materials
Identifiers
urn:nbn:se:uu:diva-328630 (URN)10.1038/s41598-017-09261-7 (DOI)000407864400051 ()
Funder
The Swedish Foundation for International Cooperation in Research and Higher Education (STINT), IB2015-6474
Available from: 2017-08-28 Created: 2017-08-28 Last updated: 2018-12-17Bibliographically approved
Rocha, I., Ferraz, N., Mihranyan, A., Strömme, M. & Lindh, J. (2016). Chemical modifications of Cladophorananocellulose to provide a non-toxicmaterial with anticoagulant properties. In: : . Paper presented at 10th World Biomaterials Congress. Montreal, Canada
Open this publication in new window or tab >>Chemical modifications of Cladophorananocellulose to provide a non-toxicmaterial with anticoagulant properties
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2016 (English)Conference paper, Poster (with or without abstract) (Refereed)
Place, publisher, year, edition, pages
Montreal, Canada: , 2016
National Category
Nano Technology
Identifiers
urn:nbn:se:uu:diva-296229 (URN)
Conference
10th World Biomaterials Congress
Available from: 2016-06-14 Created: 2016-06-14 Last updated: 2016-11-30
Rocha, I., Ferraz, N., Mihranyan, A., Strömme, M. & Lindh, J. (2016). Tailoring the structure of Cladophora nanocellulose towards a dialysis porous material with anti-coagulant properties. In: : . Paper presented at Gordon Research Conference on Structural Nanomaterials. Hong Kong, China
Open this publication in new window or tab >>Tailoring the structure of Cladophora nanocellulose towards a dialysis porous material with anti-coagulant properties
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2016 (English)Conference paper, Poster (with or without abstract) (Refereed)
Place, publisher, year, edition, pages
Hong Kong, China: , 2016
National Category
Nano Technology
Identifiers
urn:nbn:se:uu:diva-300110 (URN)
Conference
Gordon Research Conference on Structural Nanomaterials
Available from: 2016-08-02 Created: 2016-08-02 Last updated: 2016-11-30Bibliographically approved
Hua, K., Rocha, I., Zhang, P., Gustafsson, S., Ning, Y., Strømme, M., . . . Ferraz, N. (2016). Transition from bioinert to bioactive material by tailoring the biological cell response to carboxylated nanocellulose. Biomacromolecules, 17(3), 1224-1233
Open this publication in new window or tab >>Transition from bioinert to bioactive material by tailoring the biological cell response to carboxylated nanocellulose
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2016 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 17, no 3, p. 1224-1233Article in journal (Refereed) Published
Abstract [en]

This work presents an insight into the relationship between cell response and physicochemical properties of Cladophora cellulose (CC) by investigating the effect of CC functional group density on the response of model cell lines. CC was carboxylated by electrochemical TEMPO-mediated oxidation. By varying the amount of charge passed through the electrolysis setup, CC materials with different degrees of oxidation were obtained. The effect of carboxyl group density on the material’s physicochemical properties was investigated together with the response of human dermal fibroblasts (hDF) and human osteoblastic cells (Saos-2) to the carboxylated CC films. The introduction of carboxyl groups resulted in CC films with decreased specific surface area and smaller total pore volume compared with the unmodified CC (u-CC). While u-CC films presented a porous network of randomly oriented fibers, a compact and aligned fiber pattern was depicted for the carboxylated-CC films. The decrease in surface area and total pore volume, and the orientation and aggregation of the fibers tended to augment parallel to the increase in the carboxyl group density. hDF and Saos-2 cells presented poor cell adhesion and spreading on u-CC, which gradually increased for the carboxylated CC as the degree of oxidation increased. It was found that a threshold value in carboxyl group density needs be reached to obtain a carboxylated-CC film with cytocompatibility comparable to commercial tissue culture material. Hence, this study demonstrates that a normally bioinert nanomaterial can be rendered bioactive by carefully tuning the density of charged groups on the material surface, a finding that not only may contribute to the fundamental understanding of biointerface phenomena, but also to the development of bioinert/bioactive materials.

National Category
Nano Technology
Research subject
Engineering Science with specialization in Nanotechnology and Functional Materials
Identifiers
urn:nbn:se:uu:diva-267300 (URN)10.1021/acs.biomac.6b00053 (DOI)000372391800056 ()
Funder
Swedish Research Council FormasStiftelsen Olle Engkvist Byggmästare
Available from: 2015-11-19 Created: 2015-11-19 Last updated: 2018-03-15Bibliographically approved
Rocha, I., Ferraz, N., Mihranyan, A., Strömme, M. & Lindh, J. (2015). Chemical modification of Cladophora nanocellulose to provide a non-toxic material with anticoagulant properties. In: : . Paper presented at 4th International Polysaccharide Conference (EPNOE 2015), Warsaw, Poland,19-22 October 2015.
Open this publication in new window or tab >>Chemical modification of Cladophora nanocellulose to provide a non-toxic material with anticoagulant properties
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2015 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Blood purification is a common procedure for treating patients with kidney failure in which an extracorporeal device filled with a porous material containing antibodies can retain toxins from the blood. In order to avoid activation and coagulation, heparin is administrated to patients; however this sulfonated polysaccharide may cause many side effects such as intense bleeding and osteoporosis. In this project nanocellulose from Cladophora green algae was used for the development of a porous material with anticoagulant properties. A periodate oxidation followed by an amine cross-linking and subsequent reduction produced dialdehyde cellulose beads ranging from 10-100 mm in diameter with improved mechanical properties and high stability in alkaline media. This material was then sulfonated to acquire anticoagulant properties and characterized by FTIR, z-potential, condutometric titration, elemental analysis and BET surface area showing that its porosity varies with the degree of sulfonation. After extensive washing, toxicology experiments were performed with a THP-1 monocyte cell line in order to examine if the material was non-toxic and could be suitable as a matrix in blood purification.

National Category
Nano Technology
Identifiers
urn:nbn:se:uu:diva-266842 (URN)
Conference
4th International Polysaccharide Conference (EPNOE 2015), Warsaw, Poland,19-22 October 2015
Available from: 2015-11-12 Created: 2015-11-12 Last updated: 2016-11-30Bibliographically approved
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