Both cold nitrogen radiofrequency plasma and gamma irradiation have been applied to activate and functionalize the polylactic acid (PLA) surface and the subsequent lactoferrin immobilization. Modified films were comparatively characterized with respect to the procedure of activation and also with unmodified sample by water contact angle measurements, mass loss, X-ray photoelectron spectroscopy (XPS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM), and chemiluminescence measurements. All modified samples exhibit enhanced surface properties mainly those concerning biocompatibility, antimicrobial, and antioxidant properties, and furthermore, they are biodegradable and environmentally friendly. Lactoferrin deposited layer by covalent coupling using carbodiimide chemistry showed a good stability. It was found that the lactoferrin-modified PLA materials present significantly increased oxidative stability. Gamma-irradiated samples and lactoferrin-functionalized samples show higher antioxidant, antimicrobial, and cell proliferation activity than plasma-activated and lactoferrin-functionalized ones. The multifunctional materials thus obtained could find application as biomaterials or as bioactive packaging films.

A novel quaternized polysulfone with N-dimethyloctylammonium groups was investigated with respect to its surface properties, hydrophobicity, interactions with blood, and morphology. The history of the films formed from N,N-dimethylformamide/methanol and N,Ndimethylformamide/water solutions and the compositions of the solvent/nonsolvent mixtures influenced the surface morphology. Thus, atomic force microscopy investigations of the films showed pores and nodules of different sizes and intensities, which depended on the content of methanol or water in the solvent mixtures. Hydrophilicity modification, evidenced by the apolar components and the electron-acceptor and electron-donor parameters of the polar components of the surface tension parameters, was correlated with atomic force microscopy data. Surface wettability trends were analyzed on the basis of the free energy of hydration between the prepared films and water and the work of adhesion. The adhesion of red blood cells to the modified polysulfone showed the influence of the hydrophobic properties.

No abstract

The paper describes some properties of new quaternized polysulfones obtained by quaternization of chloromethylated polysulfone with different tertiary amines - N,N-dimethylethylamine and N,N-dimethyloctylamine. Hydrophilic/hydrophobic properties, morphological aspects and compatibility with red blood cells and platelets are affected by the alkyl radicals and by history of the formed films. The results obtained are useful in biomedical applications, including evaluation of bacterial adhesion to the surfaces, or utilization of modified polysulfones as semipermeable membranes

The article describes some properties of cellulose acetates (CAs) with different substitution degrees. The hydrophilic/hydrophobic properties, morphological aspects, and interface properties with red blood cells and platelets are affected by the substitution degree, synthesis conditions, history of the formed films from solutions in acetone/water nonsolvent/nonsolvent mixtures, and low pressure plasma treatment. The results obtained are useful in biomedical applications, including evaluation of bacterial adhesion onto surfaces, or utilization of CA for semipermeable membranes.