2 methyl 2 oxazoline

Methyl triflate, 2-methyl-2-oxazoline, methoxycarboxyethyl-2-oxazoline, and piperidine were obtained from Sigma Aldrich. Dialysis membrane with molecular weight cut off [MWCO] 3500 was purchased from Spectra/Pore. The following materials were purchased from Thermo/Fisher: WhatMan Anotop 0.025 μm non-sterile filters, 25 gauge 0.5 inch, long blunt needle (Strategic Applications Inc., Lake Villa, IL, USA), 40% acrylamide 29:1, TEMED, Ammonium persulphate, Malvern Folded Cap Cells, DLS cuvettes (Malvern Pananalytical, Malvern, UK), radioimmunoprecipitation assay buffer, HALT protease and phosphatase inhibitor cocktail, SuperSignal™ West Pico PLUS Chemiluminescent Substrate, iBRIGHT prestained protein ladder, Geneticin™ Selective Antibiotic (G418 Sulfate), Neurobasal Media, B27 supplement, Glutamax 100× acetonitrile, potassium carbonate, diethyl ether, methanol, agarose tablets, and sodium hydroxide. BDNF was obtained from Novoprotein, which later became Bon Opus Biosciences. PSR-PLE was obtained from Peptide Solutions LLC. Colorado calf serum was obtained from the Colorado Serum Company. We obtained Bio-Safe Coomassie Stain and Native Sample buffer for protein gels 4× from Bio-Rad, Hercules, CA, USA.

LDN-57444, 2-methyl-2-oxazoline, and other reagents for synthesizing 2-butyl-2-oxazoline (valeronitrile, cadmium acetate dehydrate and ethanolamine) and polymer (acetonitrile, n-boc-piperazine) were obtained from Sigma-Aldrich Inc (St. Louis, MO, USA).

Deposition of plasma polymers was carried out in a custom-made reactor that has been previously described previously (Chan K. M. et al., 2020 (link)). The plasma was ignited with a 13.56 MHz Radio Frequency generator coupled to a matching network (Coaxial Power System). Substrates, including glass microscope slides, silicon wafers and coverslips, were introduced into the reactor and primed with an air plasma (30 W, 3 min, 0.12 mbar). The reactor was evacuated to a base pressure of 2 × 10⁻² mbar to remove atmospheric oxygen and nitrogen from the chamber. The pressure was monitored with a pirani gauge (APG100, Edwards) and controlled with a needle valve (Chell Instrument, United Kingdom). The precursors, 2-methyl-2-oxazoline and 2-isopropenyl-2-oxazoline (Sigma Aldrich, Australia) were introduced into the reactor at a working pressure of 0.12 mbar at which point the plasma was ignited at 30 W. Deposition was conducted for 30 and 50 s after which the monomer flow was stopped using the needle valve.
For integration into the spiral microfluidic, PPOx coatings were deposited on glass microscope slides (Marienfeld, Germany) through a custom-made aluminum mask to limit the film deposition to the cell capture reservoir area.

2-Bromo-3-(bromomethyl)thiophene, thiophene 2-boronic acid (Merck-Sigma-Aldrich, Darmstadt, Germany)), 2-methyl-2-oxazoline (MeOX), poly(2-methyl-2-oxazoline), hydroxy terminated,(PMeOx, c.a.) M_n = 5000; IPD = 1.3), potassium hydroxide (KOH), sodium bicarbonate (NaHCO₃) and tetrakis(triphenylphosphine)palladium(0) (Pd(PPh₃)₄)(all from Sigma-Aldrich) were used as received. All the solvents were purified and dried by usual methods.