Biomaterials for MEMS

276 Color Inserts

Figure 10.5 Fibronectin formation (green) and actin filament formation (red) in epithelial

mHepR1 cells cultured on the biomaterial PHB (below) compared to control cultures

(above). Note that in control cultures the actin filaments are structured in fibrils showing

colocalization with fibronectin (arrow head) in contrast to PHB cultured cells, where the

organization of actin filaments is more irregular and the colocalization of fibronectin with

actin is lost (arrow head) (CLSM images taken with LSM 410, Carl Zeiss Jena). With

permission from.

33

Figure 10.9 FT-IR images of rabbit osteochondral defect at 6 weeks post-repair with TP

508 protein. The defect repair cartilage has lower collagen content (amide I area) compared

to the adjacent articular cartilage, but also has regions with PG content (PG sugar ring C-O

absorbance (985–1140 cm

−1

) of a similar magnitude to that in the native cartilage. There is

some orientation present in the repair cartilage, as evidenced by the layer of fibrils parallel

to the surface. For the orientation data, the boundaries on the color bar indicate the three

collagen fibril orientation categories with respect to the articular surface, corresponding to

amide I/amide II peak area ratios>2.7 (parallel fibrils), between 2.7 and 1.7 (random fibrils),

and <1.7 (perpendicular fibrils), respectively. With permission from.

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Color Inserts 277

Photodetector

CLSM

MPE

Pinhole

Dichroic

Mirror

Sample

Objective

Figure 10.10 Comparison of a conventional confocal microscope (CLSM) with a multi-

photon excitation (MPE) microscope.

Figure 10.11 Overlay of optical sections showing elastic fibers (green) and collagen (red)

of two TE valve leaflets, cultured under different conditions within the bioreactor system.

The differences between the tissue states were only explicitly verifiable by the use of the

MPE images. (A) TE heart valve, exposed to defined physical signals with a fixed frequency

(1 Hz) and pressure conditions (3 l/min and 60/40 mm Hg), show normal extracellular

matrix structures (bar: 20 μm). (C) Corresponding macroscopic appearance of the TE

valves. (B) TE leaflet, exposed to supra-physiologic (>200 mm Hg) pressures, revealing an

impaired matrix formation and a high amount of cell detritus (yellow). (D) Corresponding

macroscopic pictures. With permission from.

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