All materials were used as received unless otherwise stated. Tetrahydrofuran (anhydrous, ≥99.9%, inhibitor-free), chloroform (anhydrous, contains amylenes as stabilizer, ≥99%), and calcium hydride (reagent grade, 95%) were purchased from Sigma-Aldrich (St. Louis, MO). Phenylacetaldehyde (98%, stabilized), lithium di-isopropylamide mono(tetrahydrofuran) (1.5 M solution in cyclohexane, AcroSeal™), iodotrimethylsilane (95–97%), n-butyllithium (2.5 M solution in hexanes, AcroSeal™), hexanes and methylene chloride were purchased from Fisher Scientific (Houston, TX). Sodium thiosulfate pentahydrate (Proteomics grade, 99%) was purchased from Amresco, LLC (Solon, OH). 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) was purchased from Oakwood Products, Inc. (Estill, SC). Sodium sulfate anhydrous (ACS grade) and methanol (ACS grade), hydrochloric acid (36.5–38%, ACS Grade) were purchased from VWR International (Radnor, PA).
Dry toluene (HPLC Grade, 99.7%, Alfa Aesar) for polymerization was purified and dried on an Inert Pure Solv system (MD Solvent Purification system, model PS-MD-3) and degassed using three cycles of the freeze-vacuum-thaw. ε-Caprolactone (ε-CL, 99%, ACROS Organics™) was dried over calcium hydride under nitrogen overnight and distilled under reduced pressure. Magnesium 2,6-di-tert-butyl-4-methylphenoxide catalyst [Mg(BHT)2(THF)2]39 , 4-dibenzocyclooctynol (DIBO)28 initiator and DIBO-end functionalized poly(ε-caprolactone) were synthesized using methods described previously13 (link). Resins for peptide synthesis (Novabiochem®) were purchased from EMD Millipore (Billerica, MA). Fmoc-amino acids were purchased from Aapptec (Louisville, KY).
Square (22 × 22 mm) and round (8 mm) Fisherbrand™ borosilicate cover glasses (#1.5) were washed with methanol / toluene / methanol, dried with nitrogen, and cleaned with UV light (355 nm) for 3 min prior to use. After nanofibers were collected on the glass coverslips, the nanofiber mats were glued to the edges of a glass slide by a silicone sealant and dried under vacuum overnight.
Dry toluene (HPLC Grade, 99.7%, Alfa Aesar) for polymerization was purified and dried on an Inert Pure Solv system (MD Solvent Purification system, model PS-MD-3) and degassed using three cycles of the freeze-vacuum-thaw. ε-Caprolactone (ε-CL, 99%, ACROS Organics™) was dried over calcium hydride under nitrogen overnight and distilled under reduced pressure. Magnesium 2,6-di-tert-butyl-4-methylphenoxide catalyst [Mg(BHT)2(THF)2]39 , 4-dibenzocyclooctynol (DIBO)28 initiator and DIBO-end functionalized poly(ε-caprolactone) were synthesized using methods described previously13 (link). Resins for peptide synthesis (Novabiochem®) were purchased from EMD Millipore (Billerica, MA). Fmoc-amino acids were purchased from Aapptec (Louisville, KY).
Square (22 × 22 mm) and round (8 mm) Fisherbrand™ borosilicate cover glasses (#1.5) were washed with methanol / toluene / methanol, dried with nitrogen, and cleaned with UV light (355 nm) for 3 min prior to use. After nanofibers were collected on the glass coverslips, the nanofiber mats were glued to the edges of a glass slide by a silicone sealant and dried under vacuum overnight.
