Design and Synthesis of Photoreactive Polymers for Biomedical Applications - Biomimetics: Advancing Nanobiomaterials and Tissue Engineering - page 264

Protein Protein

engineering

NH 2

NH 2

NH 2

NH 2

Non-oriented

Oriented

NH 2 NH 2 NH 2

Substrate

CONH CONH CONH

All sites are exposed Partial sited are exposed

NH 2 NH 2

NH 2

CONH CONH CONH

Substrate
Photoimmobilization

Conventional immobilization

Figure 11.13 Comparison of immobilization methods. Photoimmobilization
leads to the random orientation of immobilized molecules, whereas other
covalent immobilization methods lead to some orientation because of the
uneven distribution of functional groups on the molecules being immobilized.
For genetically engineered proteins with adhesive peptide sequences on the end
chain, the recognition site is limited to the remaining part of the molecule.

Polyvinyl alcohol derivatives were also prepared by conjugation with
azidophenyl groups [51-54]. A novel photoreactive polymer, polyvi-
nyl alcohol modifi ed with azidophenyl groups, was immobilized using
micropatterning for cell culture and employed for preparing microar-
rays. The polymer is soluble in water and is spin-coated onto glass plates.
Aqueous solutions of proteins were microspotted onto the coated glass
and were fi xed by UV irradiation. Subsequently, cell adhesion on the pho-
toimmobilized protein microarray was investigated. Nonspecifi c adhe-
sion of cells onto the regions not subjected to protein microspotting was
reduced in comparison with the previously prepared microarray chip.
Adhesion of cells depended on the kind of immobilized proteins and the
types of cells. The microarray will be useful for cell diagnosis and for the
selection of biomaterials to regulate cell behavior.

11.3.2 Stimuli-Responsive Polymers

We have also synthesized some photoreactive and stimuli-responsive
polymers (to pH, temperature, ionic strength, photoirradiation, and redox
state) and prepared micropatterned surfaces [55-58]. Among the polymers,