. Author manuscript; available in PMC: 2011 Jul 28.

Published in final edited form as: Langmuir. 2007 Jan 23;23(8):4103–4107. doi: 10.1021/la0630559

Table 1. Biocompatibility of photolithographic processing steps.

Patterns of adsorbed collagen (500 μg/ml) were exposed to various photolithographic factors and evaluated on whether the ability to mediate hepatocyte attachment was preserved. These results demonstrate that photolithographic patterning can be performed on collagen-patterned substrates, using a tetramethylammonium hydroxide developer and restricting photoresist bake temperatures to below 100 ºC.

Photolithographic Process Element	Collagen bioactivity retained?
Photoresist Solvent: propylene glycol methyl ether acetate Binder: novalac resin Photoactive compound: diazonapthoquinone	Yes
Photoresist exposure 300 nm, 10 mW/cm², 35 s	Yes
Developer (Microposit MF-319) Tetramethylammonium hydroxide (TMAH), 2 min	Yes
Developer (Microposit 354) Sodium hydroxide, 2 min	No
Photoresist + ultraviolet exposure + TMAH	Yes
50 ºC 10 min on hotplate	Yes
100 ºC 10 min on hotplate	Yes
200 ºC 10 min on hotplate	No
Photoresist removal Acetone, 2 min	Yes