Nanopatterned Protein Films Directed by Ionic Complexation with Water-Soluble Diblock Copolymers
The use of ionic interactions to direct both protein templating and block copolymer self-assembly into nanopatterned films with only aqueous processing conditions is demonstrated using block copolymers containing both thermally responsive and pH responsive blocks. Controlled reversible addition–frag...
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| Format: | Article |
| Language: | en_US |
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American Chemical Society (ACS)
2014
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| Online Access: | http://hdl.handle.net/1721.1/91596 https://orcid.org/0000-0002-7272-7140 https://orcid.org/0000-0001-9264-8610 |
| _version_ | 1826199420283125760 |
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| author | Kim, Bokyung Olsen, Bradley D. Lam, Christopher Nguyen |
| author2 | Massachusetts Institute of Technology. Department of Chemical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Chemical Engineering Kim, Bokyung Olsen, Bradley D. Lam, Christopher Nguyen |
| author_sort | Kim, Bokyung |
| collection | MIT |
| description | The use of ionic interactions to direct both protein templating and block copolymer self-assembly into nanopatterned films with only aqueous processing conditions is demonstrated using block copolymers containing both thermally responsive and pH responsive blocks. Controlled reversible addition–fragmentation chain-transfer (RAFT) polymerization is employed to synthesize poly(N-isopropylacrylamide-b-2-(dimethylamino)ethyl acrylate) (PNIPAM-b-PDMAEA) diblock copolymers. The pH-dependent ionic complexation between the fluorescent protein, mCherry, and the ionic PDMAEA block is established using dynamic light scattering (DLS) and UV–vis spectroscopy. DLS shows that the size of the resulting coacervate micelles depends strongly on pH, while UV–vis spectroscopy shows a correlation between the protein’s absorption maximum and the ionic microenvironment. Zeta potential measurements clearly indicate the ionic nature of the complex-forming interactions. Spin-casting was used to prepare nanostructured films from the protein–block copolymer coacervates. After film formation, the lower critical solution temperature (LCST) of the PNIPAM blocks allows the nanomaterial to be effectively immobilized in aqueous environments at physiological temperatures, enabling potential use as a controlled protein release material or polymer matrix for protein immobilization. At pH 9.2 and 7.8, the release rates are at least 10 times faster than that at pH 6.4 due to weaker interaction between protein and PNIPAM-b-PDMAEA (PND) diblock copolymer. Because of the ionic environment in which protein is confined, the majority of the protein (80%) remains active, independent of pH, even after having been dehydrated in vacuum and confined in the films. |
| first_indexed | 2024-09-23T11:19:37Z |
| format | Article |
| id | mit-1721.1/91596 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T11:19:37Z |
| publishDate | 2014 |
| publisher | American Chemical Society (ACS) |
| record_format | dspace |
| spelling | mit-1721.1/915962022-10-01T02:50:12Z Nanopatterned Protein Films Directed by Ionic Complexation with Water-Soluble Diblock Copolymers Kim, Bokyung Olsen, Bradley D. Lam, Christopher Nguyen Massachusetts Institute of Technology. Department of Chemical Engineering Kim, Bokyung Lam, Christopher Nguyen Olsen, Bradley D. The use of ionic interactions to direct both protein templating and block copolymer self-assembly into nanopatterned films with only aqueous processing conditions is demonstrated using block copolymers containing both thermally responsive and pH responsive blocks. Controlled reversible addition–fragmentation chain-transfer (RAFT) polymerization is employed to synthesize poly(N-isopropylacrylamide-b-2-(dimethylamino)ethyl acrylate) (PNIPAM-b-PDMAEA) diblock copolymers. The pH-dependent ionic complexation between the fluorescent protein, mCherry, and the ionic PDMAEA block is established using dynamic light scattering (DLS) and UV–vis spectroscopy. DLS shows that the size of the resulting coacervate micelles depends strongly on pH, while UV–vis spectroscopy shows a correlation between the protein’s absorption maximum and the ionic microenvironment. Zeta potential measurements clearly indicate the ionic nature of the complex-forming interactions. Spin-casting was used to prepare nanostructured films from the protein–block copolymer coacervates. After film formation, the lower critical solution temperature (LCST) of the PNIPAM blocks allows the nanomaterial to be effectively immobilized in aqueous environments at physiological temperatures, enabling potential use as a controlled protein release material or polymer matrix for protein immobilization. At pH 9.2 and 7.8, the release rates are at least 10 times faster than that at pH 6.4 due to weaker interaction between protein and PNIPAM-b-PDMAEA (PND) diblock copolymer. Because of the ionic environment in which protein is confined, the majority of the protein (80%) remains active, independent of pH, even after having been dehydrated in vacuum and confined in the films. MIT Energy Initiative (Award 015728-066) 2014-11-17T18:22:29Z 2014-11-17T18:22:29Z 2012-05 2012-02 Article http://purl.org/eprint/type/JournalArticle 0024-9297 1520-5835 http://hdl.handle.net/1721.1/91596 Kim, Bokyung, Christopher N. Lam, and Bradley D. Olsen. “Nanopatterned Protein Films Directed by Ionic Complexation with Water-Soluble Diblock Copolymers.” Macromolecules 45, no. 11 (June 12, 2012): 4572–4580. https://orcid.org/0000-0002-7272-7140 https://orcid.org/0000-0001-9264-8610 en_US http://dx.doi.org/10.1021/ma2024914 Macromolecules Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Chemical Society (ACS) PMC |
| spellingShingle | Kim, Bokyung Olsen, Bradley D. Lam, Christopher Nguyen Nanopatterned Protein Films Directed by Ionic Complexation with Water-Soluble Diblock Copolymers |
| title | Nanopatterned Protein Films Directed by Ionic Complexation with Water-Soluble Diblock Copolymers |
| title_full | Nanopatterned Protein Films Directed by Ionic Complexation with Water-Soluble Diblock Copolymers |
| title_fullStr | Nanopatterned Protein Films Directed by Ionic Complexation with Water-Soluble Diblock Copolymers |
| title_full_unstemmed | Nanopatterned Protein Films Directed by Ionic Complexation with Water-Soluble Diblock Copolymers |
| title_short | Nanopatterned Protein Films Directed by Ionic Complexation with Water-Soluble Diblock Copolymers |
| title_sort | nanopatterned protein films directed by ionic complexation with water soluble diblock copolymers |
| url | http://hdl.handle.net/1721.1/91596 https://orcid.org/0000-0002-7272-7140 https://orcid.org/0000-0001-9264-8610 |
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