1. Cell-Material interaction
BAECs on PET fibres
Cell nuclei stained in blue with DAPI
Actin filaments stained in red with rhodamin-phalloidin

2. Where is research going: tissue engineering
How communicating with cells?

3. Promoting endothelialization

4. Fibronectin RGD (cell adhesion) Two configurations in human body:
Soluble globular conformation in blood plasma
Fibrillar insoluble conformation in ECM
Functions:
Cell adhesion, migration, and survival.
RGD (cell adhesion)

5. Surface functionalization
PTFE (chemically inert)
Surface amino groups
NH3 or N2/H2 Plasma
Linking arms
grafting with
amino moieties
Goal: FN immobilization
FN immobilization

6. Peptide conjugation strategy
NH2
Piranha
Activation
(CH2)3
Si(OEt)3
Aminosilylation NH S
H2N
SDGRGG-(PEG3-TAMRA)K-G
FITC-LYLMSIASLETPVSSAKPIK
S-SMPB grafting
SMPB crosslinker
Peptides immobilization
RGD-TAMRA
BMP-2-FITC
Cysteine
H2N

7. XPS characterization Relative surface concentration Semi-quantitative
F KLL
F1s
31,3%
SMPB
O1s
8,2%
C1s
54,6%
N1s
5,9%
F KLL
F1s
38,6%
Glutaric
anhydride
O1s
7,2%
C1s
48,6%
Relative surface concentration
Semi-quantitative
N1s
5,6%
F KLL
F1s
31,8%
Plasma
N1s
13,8%
C1s
51,0%
O1s
3,4%
F1s
65,8%
F KLL
Virgin PTFE
C1s
34,2%
1200
1000
800
600
400
200
Binding Energy (eV)

8. Why patterning? Bar scale = 2.5 µm Cell culture In vivo
In vivo, fibrillogenesis leads to the cell-mediated reorganization of fibronectin into clustered fibrils of µm-scale length...
JE Schwarzbauer and DW DeSimone, Cold Spring Harb Perspect Biol 2011; 3: a005041

9. Why patterning? Bar scale = 1 µm
...with repeating units spaced by ~71 nm
T Pompe, L Renner, and C Werner, Biophys. J., 2005; 88:

10. Cell geometry and differentiation
R Peng, X Yao, and J Ding, Biomaterials, 2011; 32:

11. Cell geometry and differentiation: single cell (mesenchymal stem cells)
R Peng, X Yao, and J Ding, Biomaterials, 2011; 32:

12. Cell geometry and differentiation: single cell
R Peng, X Yao, and J Ding, Biomaterials, 2011; 32:

13. Cell geometry and differentiation: single cell
R Peng, X Yao, and J Ding, Biomaterials, 2011; 32:

14. Promoting the differentiation of mesenchymal stem cells: strategy
Glass material
ECM-derived peptides
Human bone marrow MSCs
Bio-inertness
Smoothness
Low cost
High osteogenic potential
Reproducible results
Crosstalk
Adhesive RGD
Osteoinductive BMP-2
Mimicking native
ECM features