Fluorolink s10

Hydrophobic dot arrays were manufactured by printing fluorine-silane material. The fluorine-silane material (Fluorolink S10®) was purchased from Solvay Solexis. According to the product data sheet, the material composed of perfluoropolyether with ethoxysilane terminal groups that reduce surface energy of applied substrates thereby improving the repellency to water. The material has a high kinematic viscosity of 18,000 cst at 20 °C, which is too high to be suitable for the use of ink. A fluid of SU-8 developer purchased from Microchem was revealed to be a proper diluent for the printable PFP ink. 1.2 mL of PFP was diluted with 2 mL of SU-8 developer. This volume ratio was determined to sustain the printer cartridge as long as possible. A piezoelectric inkjet printer (Dimatix DMP-2831, Fujifilm) was used to deposit the polymer dot arrays. The printer head is composed of an array of 16 nozzles with 21.5 μm opening size. Stable droplets were ejected onto the stainless steel (SS 304) substrate by setting 11.5 μs and 24 V pulse at a frequency of 20 kHz (Fig. S1). The polymer dot size was determined by physical and chemical properties of the polymer inks and substrate, and the smallest one with 75 μm diameter dots was obtained under our current processes. Printing pattern drawing was achieved by software installed in the printer.

Reagents
for peptide synthesis
(Fmoc-protected amino acids, resins, activation, and deprotection
reagents) were purchased from Iris Biotech GmbH (Waldershofer Str.
49–51, 95615); EDC/NHS, PDMS, and CRP (C- Reactive Protein)
were from Sigma-Aldrich. VEGF (Recombinant Human VEGF165) was purchased
from Peprotech. Anti-CRP (Anti-C Reactive Protein antibody (FITC)
(ab19174)) and Anti-VEGF (Anti-Recombinant Human VEGF antibody (FITC))
were from Abcam. TNF-α and Anti-TNF-α (Anti-Tumor Necrosis
Factor-α antibody (FITC)) were from Prospec. Solvents for peptide
synthesis and HPLC analyses were purchased from Sigma-Aldrich; reversed-phase
columns for peptide analysis and the LC–MS system were supplied,
respectively, from Agilent Technologies and Waters (Milan, Italy).
All SPR reagents and chips were purchased from AlfaTest (Rome, Italy).
PMMA substrates used in this study were purchased from the same batch
of the polymer supplier (Good Fellow Cambridge Limited, England);
Fluorolink S10 was from Solvay. Pooled human serum from healthy donors
was supplied by Lonza (Life Technology Ltd., Paisley, UK). All chemicals
were used as received.