Characterization of biodegradable polymers irradiated with swift heavy ions

N.G. SALGUERO; M. F. DEL GROSSO; H. DURÁN; P.J. PERUZZO; J.I. AMALVY; C. ARBEITMAN; G. GARCÍA BERMÚDEZ

Itapema

Conferencia; 20th International Conference on Ion Beam Analysis; 2011

There is an increasing interest in developing new methods to induce controlled cell adhesion onto polymeric materials, in view of their application as biomaterials.The critical step in all these methods involves the modification of the polymer surfaces because the interaction between the cells and polymers depends on the surface properties. These modifications should not affect the degradation and biocompatibility of biomaterials.The surface modifications induced by swift heavy ions (SHI) might be a good choice. They are very different to those induce by classical low ionizing particles, due to their high electronic stopping power, and produce interesting modifications in a few microns of depth as we can find in recent works [1,2] and theirs references.Two biodegradable polymers as: Polyhydroxybutyrate (PHB) and Poly-L-Lactide Acid (PLLA) were irradiated at a tandem accelerator TANDAR CNEA-Argentina using Carbon and Sulfur beams with different energies and fluences. Pristine and irradiated samples were degradated by immersion in a phosphate buffer with pH = 7.4 and characterized. Polymers characterization was carried out using an Environmental Scanning Electron Microscope (ESEM), Differential Scanning Calorimeter (DSC), Thermo Gravimetric Analysis (TGA), Infrared Spectroscopy with Fourier Transform (FTIR-ATR), Goniometer for Contact Angle Determination (CA) and X-ray Photoelectron Spectroscopy (XPS).The analysis after irradiation showed a decrease in the contact angle measurements and changes in carbonyl groups signal at FTIR-ATR spectra (some pick area grows with irradiation). In the degradated samples there were not differences between irradiated and pristine polymers. Degradated polymers showed an increase in crystallinity that was in agreement with the results reported in the bibliography [3].