In vitro studies of PEG thin films with different molecular weights deposited by MAPLE

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2012-10, Vol.109 (1), p.223-232
• Main Authors: Paun, Irina Alexandra, Ion, Valentin, Luculescu, Catalin-Romeo, Dinescu, Maria, Canulescu, Stela, Schou, Jørgen
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Laser deposition; Machines; Manufacturing; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Nanotechnology; Optical and Electronic Materials; Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Physics; Physics and Astronomy; Processes; Surfaces and Interfaces; Thin Films
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-012-7038-8

In this work, polyethylene glycol (PEG) films were produced by Matrix Assisted Pulsed Laser Evaporation (MAPLE). The possibility to tailor the properties of the films by means of polymer molecular weight was explored. The films of PEG of average molecular weights 400 Da, 1450 Da, and 10000 Da (PEG 400 , PEG 1450 , and PEG 10000 ) were investigated in vitro, in media similar with those inside the body (phosphate buffer saline PBS with pH 7.4 and blood). The mass of the polymer did not change during this treatment, but the polymer molecular weight was found to strongly influence the films properties and their behavior in vitro. Thus, immersion in PBS induced swelling of the PEG films, which was more pronounced for PEG polymers of higher molecular weight. Prior to immersion in PBS, the PEG films of higher molecular weight were more hydrophilic, the water contact angles decreasing from ∼66 grd for PEG 400 to ∼41 grd for PEG 1450 and to ∼15 grd for PEG 10000 . The same trend was observed during immersion of the PEG films in PBS. Before immersion in PBS, the refractive index of the films increased from ∼1.43 for PEG 400 to ∼1.48 for PEG 1450 and to ∼1.68 for PEG 10000 . During immersion in PBS the refractive index decreased gradually, but remained higher for the PEG molecules of higher mass. Finally, blood compatibility tests showed that the PEG films of higher molecular weight were most compatible with blood.