Surface modification of starch based biomaterials by oxygen plasma or UV-irradiation

Radiation is widely used in biomaterials science for surface modification and sterilization. Herein, we describe the use of plasma and UV-irradiation to improve the biocompatibility of different starch-based blends in terms of cell adhesion and proliferation. Physical and chemical changes, introduced by the used methods, were evaluated by complementary techniques for surface analysis such as scanning electron microscopy, atomic force microscopy, contact angle analysis and X-ray photoelectron spectroscopy. The effect of the changed surface properties on the adhesion of osteoblast-like cells was studied by a direct contact assay. Generally, both treatments resulted in higher number of cells adhered to the modified surfaces. The importance of the improved biocompatibility resulting from the irradiation methods is further supported by the knowledge that both UV and plasma treatments can be used as cost-effective methods for sterilization of biomedical materials and devices.I. P. thanks the FCT for providing her a postdoctoral scholarship (SFRH/BPD/8491/2002). This work was partially supported by FCT, through funds from the POCTI and/or FEDER programs, The European Union funded STREP Project HIPPOCRATES (NNM-3-CT-2003-505758) and the European NoE EXPERTISSUES (NMP3-CT-2004-500283)

Effect of chemo- and/or radiotherapy with regard to cell proliferation and FDG-PET.

© 2003 The Society of Nuclear Medicin

Influence of plasma functionalization of poly(propylene) with acrylic acid on the nucleation of CaCO3

Poly(propylene) surfaces were modified by polymerization of acrylic acid using an RF plasma technique. Whereas a stable and reproducible hydrophilicity is obtained even after short treatment times, the thickness of the deposited layer, and thus the concentration of -COOH functional groups per substrate surface area, increases with plasma exposure time. The modified-poly(propylene) samples were exposed to aqueous solutions supersaturated with respect to CaCO3. Even though the polymer surfaces show a significant affinity for the adsorption of CA(2+) ions, the density of nucleation sites for calcite is reduced in comparison to untreated poly(propylene). This result can be explained by the special conditions in porous ("gelatinous") growth media and high disorder provided by the plasma-polymerized layers