Surface modification of PCL electrospun nano fibers via NaOH Materials Needed: NaOH stock solution PCL nano fibers Distilled water Deionized water 6 well culture plate 50 mL polyethylene tube Method:  Prepare a stock solution of 50mL of 5M NaOH solution by diluting 10 g NaOH with 50 mL distilled water in a 50 mL tube. Dilute solutions of 1M and 0.5M can be made as needed by performing appropriate calculations  (NaOH is highly corrosive and should be handled carefully. Any contact with skin should be thoroughly washed with water for 10‐15 minutes. Gloves should be worn when handling NaOH solution)  Label wells 1 and 4 with 3 hours, wells 3 and 6 with 1 hour and leave wells 2 and 5 empty. Label wells 1 and 3 with 0.5M and wells 4 and 6 with 1M.  Prepare 4 PCL fibers of approximately 1.5 cm in length and place one in each of the 4 wells labeled.  Add approximately 2 mL of NaOH solution to the fibers and shake the culture plate to allow solution to spread onto the surface. Allow the reaction to occur for three hour.  Remove the NaOH solution and wash the fibers with deionized water three times. Soak overnight in deionized water to remove any NaOH residue.  Remove the deionized water and put the culture plate in the refrigerator to use for future analysis the next day RGD Immobilization: Materials Needed: RGD peptide solution 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide solution MES buffer NHS solution The method stated is for treatment of 2 fibers. 
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Prepare 0.5M MES buffer solution at pH of 5.5. Prepare stock solutions of NHS and RGD peptide if obtained in powder form. Prepare 5 mL solution containing 0.5M MES, 0.143 mg/mL NHS and 0.904 mg/mL of EDC Prepare another 5 mL solution containing 0.5M MES and 0.33 µg/mL of RGD peptide solution Soak the NaOH treated fibers in 2.5 mL of 0.5M MES buffer each for one hour at room temperature Aspirate the solution and add 2.5 mL of MES + NHS+EDC solution prepared to each fiber and treat for 1 hour at room temperature Aspirate the solution and add 2.5 mL of MES + RGD solution to each fiber and allow the reaction to occur for 3 hours at room temperature. Aspirate the solution and prepare the modified fibers for appropriate use. Sterilize for cell seeding, drying for FTIR or contact angle measurement and sending them off campus for XPS