Figure 3.

(A) Biocompatibility results of incremental improvements in biocompatibility during post-processing for FormLabs Clear V4: Clear Resin alone showed the lowest survival rate, while washing with isopropyl alcohol (IPA) resulted in the greatest increase of survival. Surprisingly, thermal treatment after IPA washing reduced the biocompatibility slightly even though the result was above the accepted values for HL1 cells. The combination of IPA, UV, and autoclave resulted in the greatest collective viability. (B) Coating encapsulation of FormLabs’ High Temp Resin to improve biocompatibility: All samples were washed with IPA, exposed to UV for 6 min, and subsequently autoclaved. SU-8 and polystyrene had a rather small impact on the biocompatibility. Medco/PET and gold resulted in slightly better biocompatibility, and encapsulation in PDMS provided the best results and was subsequently used. (C) Biocompatibility of the different resins before and after PDMS coating encapsulation. (D) Biocompatibility results of the different resins where the chips were only coated with fibronectin/gelatin solution as opposed to the entire culture well. Error bars here are standard error, and p < 0.01 for each of the four graphs.