简介: |
This contribution will discuss the use of polymer brushes prepared via surface-initiated atom transfer radical polymerization (SI-ATRP) as platforms for the fabrication of protein function microarrays, bioactive surface coatings and microstructured inorganic thin films.
Polymer brushes prepared via SI-ATRP of poly(ethylene glycol)methacylate (PEGMA) provide a thin polymer layer, which is not only resistant towards the non-specific adsorption of proteins, but which also contains hydroxyl groups that can be used to covalently immobilize proteins or small peptide ligands.1 Functionalization of these brushes with benzylguanine allows the covalent, chemoselective immobilization of O6-alkylguanine-DNA-alkyltransferase (AGT) fusion proteins, which were successfully used to detect protein-protein interactions.2 Amongst others, the AGT-mediated immobilization offers the following advantages: (i) immobilization occurs exclusively via the AGT fusion and leaves the protein of interest accessible for interactions with other molecules, (ii) functionalization is chemoselective and can be carried out directly from crude cell lysates without the need for purification steps.
In the second example, it will be shown that modification of polyPEGMA brushes with short RGD-based cell adhesion peptides provides surface coatings, which are able to induce integrin-specific adhesion of human umbilical vein endothelial cells (HUVECs) and which may be of interest as coatings to promote endothelialization of blood contacting biomaterials.3
In the last part of the presentation, a novel approach for the fabrication of microstructured calcite thin films will be presented.4,5 The process uses photolithographically patterned poly(methacrylic acid) (PMAA) brushes grown via SI-ATRP as ionotropic matrices to produce crystalline calcite films that are an exact 3D replica of the PMAA brush. The proposed strategy combines three key elements: (i) the use of photolithographic techniques to prepare microstructured PMAA brushes; (ii) the ability of the PMAA brushes to stabilize amorphous calcium carbonate (ACC) and (iii) the possibility to convert the metastable ACC phase into a polycrystalline calcite film via a thermal treatment. While the lateral dimensions of the microstructured calcite film are defined by the lithographic techniques that are used to prepare the micropatterned PMAA brush, the thickness of the films can be adjusted via the thickness of the PMAA brush, which can be controlled due to the “living” nature of the SI-ATRP procedure.
1) S. Tugulu, A. Arnold, I. Sielaff, K. Johnsson, H.-A. Klok, Protein functionalized polymer brushes, Biomacromolecules 2005, 6, 1602 – 1607.
2) I. Sielaff, A. Arnold, G. Godin, S. Tugulu, H.-A. Klok, K. Johnsson, Protein function microarrays based on self-immobilizing and self-labeling fusion proteins, ChemBioChem 2006, 7, 194 – 202.
3) S. Tugulu, P. Silacci, N. Stergiopulos, H.-A. Klok, RGD-functionalized polymer brushes as substrates for the integrin specific adhesion of human umbilical vein endothelial cells, Biomaterials 2007, 28, 2536 – 2546.
4) S. Tugulu, M. Harms, M. Fricke, D. Volkmer, H.-A. Klok, Polymer brushes as ionotropic matrices for the directed fabrication of microstructured calcite thin films, Angew. Chem. 2006, 118, 7619 – 7623; Angew. Chem. Int. Ed. 2006, 45, 7458 – 7461.
5) S. Tugulu, R. Barbey, M. Harms, M. Fricke, D. Volkmer, A. Rossi, H.-A. Klok, Synthesis of poly(methacrylic acid) brushes via surface-initiated atom transfer radical polymerization of sodium methacrylate and their use as substrates for the mineralization of calcium carbonate, Macromolecules 2007, 40, 168 – 177. |
