Surface modification of curcumin-loaded ethylene vinyl acetate polymer films by dielectric barrier discharge plasma: synthesis, characterization and anti-cancer drug delivery applications

Abstract Plasma treatment is one of the emerging ways used for the surface modification of polymer films, cotton, fabrics and nanoparticles etc. Recently, Dielectric Barrier Discharge (DBD) plasma has gained importance in the biomedical applications as it can be operated at atmospheric pressure and room temperature. In the present research work, the effects of DBD plasma on the Poly (ethylene-co-vinyl acetate) (EVA) polymer is subjected to surface modification by argon and helium plasma for drug delivery applications to attain higher drug release profiles is investigated. According to the results, there is a remarkable increase in the surface hydrophilicity and roughness of the treated films which is observed and confirmed by water contact angle and AFM respectively. The least contact angle value has been obtained from 15 min plasma treatment at 30 kV. This shows the importance of plasma treatment time and plasma voltages in the surface wettability of a polymer films. There is a decrease in contact angle values for the increase in plasma voltages and treatment time. The untreated EVA polymer has an avearage surface roughness (Ra) of 9.59 nm while the argon and helium plasma treated polymer film a shows an increase in surface roughness of 48.36 nm and 55.54 nm respectively. Surface roughness increases due to the increase in polar bonds on the material surface and thus results in the decrease in water contact angle. The more aggressive the plasma treatment, the rougher the surface and thus contributes to the increase in wettability. The FT-IR and SEM analysis confirms the chemical state and surface morphology of the polymer film. The reactive species in both argon and helium plasma are identified using OES spectral analysis. The in-vitro drug release studies showed that after both the argon and helium plasma treatment, there is a significant increase in drug release profiles with increase in treatment time. Helium plasma showed a slightly higher drug release rate due to the increase in hydrophilic nature than argon plasma treatment. The results indicated that a higher drug release has been achieved using DBD plasma treatment. This reveals that surface modification of DBD plasma on EVA polymer provides a highly advanced and efficient method for faster drug delivery systems.