Details
| Original language | English |
|---|---|
| Pages (from-to) | 117-128 |
| Number of pages | 12 |
| Journal | Acta Biomaterialia |
| Volume | 59 |
| Early online date | 21 Jun 2017 |
| Publication status | Published - 1 Sept 2017 |
| Externally published | Yes |
Abstract
Thermoresponsive polymer coatings, optimized for cell adhesion and thermally-triggered cell detachment, allow the fabrication of confluent cell sheets with intact extracellular matrix. However, rational design guidelines for such coatings are rare, since temperature-triggered cell adhesion and detachment from thermoresponsive surfaces are mechanistically not well understood. Herein, we investigated the impact of molecular weight (2, 9, 24 kDa), grafting density (0.04–1.4 chains nm−2), morphology, and roughness of well-characterized thermoresponsive poly(glycidyl ether) brushes on the cell response at 37 and 20 °C. NIH 3T3 mouse fibroblasts served as a model cell line for adhesion, proliferation, and cell sheet detachment. The cell response was correlated with serum protein adsorption from cell culture medium containing 10% fetal bovine serum. Intact cell sheets could be harvested from all the studied poly(glycidyl ether) coated surfaces, irrespective of the molecular weight, provided that the morphology of the coating was homogenous and the surface was fully shielded by the hydrated brush. The degree of chain overlap was estimated by the ratio of twice the polymer's Flory radius in a theta solvent to its interchain distance, which should be located in the strongly overlapping brush regime (2 Rf/l > 1.4). In contrast, dense PNIPAM (2.5 kDa) control monolayers did not induce protein adsorption from cell culture medium at 37 °C and, as a result, did not allow a significant cell adhesion. These structural design parameters of functional poly(glycidyl ether) coatings on gold will contribute to future engineering of these thermoresponsive coatings on more common, cell culture relevant substrates. Statement of Significance Cell sheet engineering as a scaffold-free approach towards tissue engineering resembles a milestone in regenerative medicine. The fabrication of confluent cell sheets maintains the extracellular matrix of cells which serves as the physiological cell scaffold. Thermoresponsive poly(glycidyl ether)s are highly cell-compatible and brushes thereof promote cell adhesion and growth without modification with additional cell adhesive ligands. Thus, a direct correlation of temperature-dependent serum protein adsorption and cell response with surface design parameters such as grafting density and molecular weight became accessible. Hence, surface engineering parameters of well-defined poly(glycidyl ether) monolayers for reproducible cell sheet fabrication have been identified. These design guidelines may also prove beneficial in the development of other brush-like thermoresponsive coatings for cell sheet engineering.
Keywords
- AFM, Brushes, Cell sheet fabrication, Grafting density, Molecular weight, Protein adsorption, Self-assembled monolayer, SPR, Thermoresponsive
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Biotechnology
- Materials Science(all)
- Biomaterials
- Biochemistry, Genetics and Molecular Biology(all)
- Biochemistry
- Engineering(all)
- Biomedical Engineering
- Biochemistry, Genetics and Molecular Biology(all)
- Molecular Biology
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Acta Biomaterialia, Vol. 59, 01.09.2017, p. 117-128.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Thermoresponsive poly(glycidyl ether) brushes on gold
T2 - Surface engineering parameters and their implication for cell sheet fabrication
AU - Heinen, Silke
AU - Cuéllar-Camacho, José Luis
AU - Weinhart, Marie
N1 - Funding information: The authors kindly acknowledge financial support from the German Federal Ministry of Education and Research (BMBF) via the grant FKZ: 13N13523 and from the Freie Universit?t Focus Area NanoScale. S.H. is grateful to the FCI for a Chemiefonds Scholarship. We thank Dr. Anke Hoppensack for proof reading and helpful comments during the preparation of this manuscript. The authors kindly acknowledge financial support from the German Federal Ministry of Education and Research (BMBF) via the grant FKZ: 13N13523 and from the Freie Universität Focus Area NanoScale. S.H. is grateful to the FCI for a Chemiefonds Scholarship. We thank Dr. Anke Hoppensack for proof reading and helpful comments during the preparation of this manuscript.
PY - 2017/9/1
Y1 - 2017/9/1
N2 - Thermoresponsive polymer coatings, optimized for cell adhesion and thermally-triggered cell detachment, allow the fabrication of confluent cell sheets with intact extracellular matrix. However, rational design guidelines for such coatings are rare, since temperature-triggered cell adhesion and detachment from thermoresponsive surfaces are mechanistically not well understood. Herein, we investigated the impact of molecular weight (2, 9, 24 kDa), grafting density (0.04–1.4 chains nm−2), morphology, and roughness of well-characterized thermoresponsive poly(glycidyl ether) brushes on the cell response at 37 and 20 °C. NIH 3T3 mouse fibroblasts served as a model cell line for adhesion, proliferation, and cell sheet detachment. The cell response was correlated with serum protein adsorption from cell culture medium containing 10% fetal bovine serum. Intact cell sheets could be harvested from all the studied poly(glycidyl ether) coated surfaces, irrespective of the molecular weight, provided that the morphology of the coating was homogenous and the surface was fully shielded by the hydrated brush. The degree of chain overlap was estimated by the ratio of twice the polymer's Flory radius in a theta solvent to its interchain distance, which should be located in the strongly overlapping brush regime (2 Rf/l > 1.4). In contrast, dense PNIPAM (2.5 kDa) control monolayers did not induce protein adsorption from cell culture medium at 37 °C and, as a result, did not allow a significant cell adhesion. These structural design parameters of functional poly(glycidyl ether) coatings on gold will contribute to future engineering of these thermoresponsive coatings on more common, cell culture relevant substrates. Statement of Significance Cell sheet engineering as a scaffold-free approach towards tissue engineering resembles a milestone in regenerative medicine. The fabrication of confluent cell sheets maintains the extracellular matrix of cells which serves as the physiological cell scaffold. Thermoresponsive poly(glycidyl ether)s are highly cell-compatible and brushes thereof promote cell adhesion and growth without modification with additional cell adhesive ligands. Thus, a direct correlation of temperature-dependent serum protein adsorption and cell response with surface design parameters such as grafting density and molecular weight became accessible. Hence, surface engineering parameters of well-defined poly(glycidyl ether) monolayers for reproducible cell sheet fabrication have been identified. These design guidelines may also prove beneficial in the development of other brush-like thermoresponsive coatings for cell sheet engineering.
AB - Thermoresponsive polymer coatings, optimized for cell adhesion and thermally-triggered cell detachment, allow the fabrication of confluent cell sheets with intact extracellular matrix. However, rational design guidelines for such coatings are rare, since temperature-triggered cell adhesion and detachment from thermoresponsive surfaces are mechanistically not well understood. Herein, we investigated the impact of molecular weight (2, 9, 24 kDa), grafting density (0.04–1.4 chains nm−2), morphology, and roughness of well-characterized thermoresponsive poly(glycidyl ether) brushes on the cell response at 37 and 20 °C. NIH 3T3 mouse fibroblasts served as a model cell line for adhesion, proliferation, and cell sheet detachment. The cell response was correlated with serum protein adsorption from cell culture medium containing 10% fetal bovine serum. Intact cell sheets could be harvested from all the studied poly(glycidyl ether) coated surfaces, irrespective of the molecular weight, provided that the morphology of the coating was homogenous and the surface was fully shielded by the hydrated brush. The degree of chain overlap was estimated by the ratio of twice the polymer's Flory radius in a theta solvent to its interchain distance, which should be located in the strongly overlapping brush regime (2 Rf/l > 1.4). In contrast, dense PNIPAM (2.5 kDa) control monolayers did not induce protein adsorption from cell culture medium at 37 °C and, as a result, did not allow a significant cell adhesion. These structural design parameters of functional poly(glycidyl ether) coatings on gold will contribute to future engineering of these thermoresponsive coatings on more common, cell culture relevant substrates. Statement of Significance Cell sheet engineering as a scaffold-free approach towards tissue engineering resembles a milestone in regenerative medicine. The fabrication of confluent cell sheets maintains the extracellular matrix of cells which serves as the physiological cell scaffold. Thermoresponsive poly(glycidyl ether)s are highly cell-compatible and brushes thereof promote cell adhesion and growth without modification with additional cell adhesive ligands. Thus, a direct correlation of temperature-dependent serum protein adsorption and cell response with surface design parameters such as grafting density and molecular weight became accessible. Hence, surface engineering parameters of well-defined poly(glycidyl ether) monolayers for reproducible cell sheet fabrication have been identified. These design guidelines may also prove beneficial in the development of other brush-like thermoresponsive coatings for cell sheet engineering.
KW - AFM
KW - Brushes
KW - Cell sheet fabrication
KW - Grafting density
KW - Molecular weight
KW - Protein adsorption
KW - Self-assembled monolayer
KW - SPR
KW - Thermoresponsive
UR - http://www.scopus.com/inward/record.url?scp=85021052293&partnerID=8YFLogxK
U2 - 10.1016/j.actbio.2017.06.029
DO - 10.1016/j.actbio.2017.06.029
M3 - Article
C2 - 28647625
AN - SCOPUS:85021052293
VL - 59
SP - 117
EP - 128
JO - Acta Biomaterialia
JF - Acta Biomaterialia
SN - 1742-7061
ER -