Journal of Applied Research in Chemical-Polymer Engineering

Abstract Research subject: Contact lens-based drug delivery is expected to be more efficient due to sustained release of drug and increased residence time in the tear film. In particular, hydrogel has been applied in contact lenses due to impressive function such as biocompatibility, wettability and optical transparency. Nevertheless, hydrogel lenses suffer from low oxygen permeability. To reduce the shortage of oxygen supply, the silicone-based polymers were used to improve the oxygen permeability. Vitamin E as a diffusion barrier could be introduced into silicone hydrogel contact lenses to extend drug release due to its lipophilic barrier.
Research approach: In this research, poly(3-(methacryloyloxy)propyltris(trimethyl-siloxy) silane-co-2-hydroxyethyl methacrylate) (poly(TRIS-co-HEMA)) copolymers were synthesized in order to evaluate the potential of these copolymers to be used as contact lens materials. The obtained copolymers were characterized using Fourier transform infrared spectroscopy, transmittance analysis, contact angle measurement and water content. The vitamin E was incorporated into copolymer films and the effect of vitamin E loading on extended drug delivery for diclofenac sodium were examined.
Main results: The equilibrium water content (EWC) of the synthesized poly(TRIS-co-HEMA) copolymers were proportional to the hydrophilic PHEMA content. The maximum value of surface hydrophilicity was 56.4°, corresponding to an equilibrium water content of 39%. Poly(TRIS-co-HEMA) films exhibited high transparency in the visible light wave range. Incorporation of vitamin E did not have significant impact on the wettability, EWC and transparency of the copolymer films. The results showed that with vitamin E loading in the copolymer film, the diclofenac release time could be increased to 90 h, which was a 3 fold increase compared to the diclofenac release duration by copolymer film without vitamin E loading. The vitamin E loaded poly(TRIS1-co-HEMA8) copolymer films could be very useful vehicles for extended drug delivery of diclofenac.

Abstract Hemodialysis is a process of purifying the blood of a person whose kidneys are not working normally. Polyethersulfone membrane has the most application in blood purification because of its unique features, but its hydrophobic nature results in poor biocompatibility. When PES-based membranes are contacted with blood, proteins tend to adsorb onto the polymer surface, and this protein layer causes any adverse effects such as the coagulation of blood cells and platelet adhesion. The biocompatibility of pristine PES membrane can be improved by different modification methods. The aim of this research is to improve polyethersulfone (PES) membrane hydrophilicity and antifouling properties by adding pluronic F-127, poly(ethylene oxide)−poly(propylene oxide)−poly(ethylene oxide) (PEO-PPO-PEO) block copolymer, to the dope solution. In this regard, PPO hydrophobic molecules are bound to PES chains due to hydrophobic–hydrophobic interactions, and membrane hydrophilicity would be improved because of hydrophilic PEO segments. To investigate the effect of adding pluronic F-127 on membrane performance, water contact angle, mechanical properties and filtration tests were carried out. Membranes morphology were characterized by SEM microscopy. Results showed that the addition of pluronic F-127 to the polymeric solution caused permeate flux increase up to 554 L/m²h due to membrane pore size growth and contact angle decrease. Moreover, addition of pluronic F-127 caused a decrease in the tensile strength of the PES/Pluronic F-127 membranes. PES/Pluronic F-127 membranes have improved fouling resistance compared to the pristine membrane.