Interplay Between PEO Tether Length and Ligand Spacing Governs Cell Spreading on RGD-Modified PMMA-g-PEO Comb Copolymers
| Autor: | Anne M. Mayes, Linda G. Griffith, Ikuo Taniguchi, William A. Kuhlman |
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| Rok vydání: | 2007 |
| Předmět: |
Time Factors
Polymers and Plastics Polymers Surface Properties Biocompatible Materials Bioengineering Peptide Ligands Protein Engineering Polyethylene Glycols Biomaterials Focal adhesion chemistry.chemical_compound Polymer chemistry Cell Adhesion Fluorescence Resonance Energy Transfer Materials Chemistry Copolymer Polymethyl Methacrylate Methyl methacrylate Cell adhesion chemistry.chemical_classification Adhesion Polymer Actins Molecular Weight Förster resonance energy transfer Models Chemical chemistry Biophysics Peptides Oligopeptides |
| Zdroj: | Biomacromolecules. 8:3206-3213 |
| ISSN: | 1526-4602 1525-7797 |
| DOI: | 10.1021/bm070237o |
| Popis: | The effects of tether length on cell adhesion to poly(methyl methacrylate)-graft-poly(ethylene oxide), PMMA-g-PEO, comb copolymer films functionalized with the adhesion peptide RGD were investigated. Copolymers having PEO tether lengths of 10 and 22 EO segments were synthesized and coupled with a synthetic peptide that contained both RGD and the synergy sequence PHSRN. Cell spreading assays revealed that the longer polymer tethers increased the rate of spreading and reduced the time required for fibroblasts to form focal adhesions. Fluorescence resonance energy transfer (FRET) measurements indicated a mean separation between integrin-bound peptides of 15.6 +/- 1.4 nm for combs with long (22-mer) tethers, compared with 17.5 +/- 1.3 nm for short (10-mer) tethers, on films of comparable peptide density (approximately 2500 peptides/microm2). The results suggest that the added mobility afforded by the more extensible tethers encouraged the formation of focal adhesions by allowing cells to reorganize tethered peptides on the nanometer length scale. In addition, adhesion peptides were selectively coupled to 10-mer or 22-mer PEO tethers within a bimodal brush to investigate stratification effects on cell adhesion. Peptides bound by short tethers in a bed of long unsubstituted chains resulted in surfaces that resisted, rather than promoted, cell adhesion. By contrast, when long peptide tethers were employed with short unsubstituted chains, cell attachment and spreading were comparable to that found on a monomodal brush of long chains at equivalent peptide density. |
| Databáze: | OpenAIRE |
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