Methods: Polyether-urethane (PEU) was synthesised via two-step solution polymerisation. The functional groups of the polymer (-NH) and the available hydroxyl group of Doxycycline can be bonded through a diisocynate coupling agent. Polyurethane films were first treated with 10 (w/v) % of Methylene bisphenyl diisocyanate (MDI) solution in toluene at 50 C° and then immersed in 5(w/v) % solution of DX in toluene at 80 °C for 2 hours. The chemical structure of the prepared membranes was characterised using ATR-FTIR and Raman spectroscopy. Surface energy and wettability of polymeric membranes were determined by contact angle measurement. Data were compared using one-way analysis of variance and p values ≤ 0.05 were considered statistically significant.
Results: The extent of reaction of MDI with PEU surfaces was measured from FTIR spectra as the ratio of the NCO absorption at 2250 cm-1 and C=C of MDI at 1600 cm-1. Spectroscopy results confirmed the bonding of the DX to the polyurethane surface by disappearance of isocyanate peak at 2250 cm-1 and formation of urethane bands at (C=O) 1721 and (N-H) 3350 cm-1. It was found that the grafting of doxycycline led to surface wettability increase which affects the adhesion of the membrane to the surrounding tissue.
Conclusion: Results suggest that doxycycline was successfully grafted to the polymer surface and it is envisaged that the grafted membranes might enhance GTR efficacy with antibacterial effect and increased hydrophilicity