This work is focused on preparation and characterization of the carbon nanostructures created by flash evaporation and subsequent thermal stress of the poly-L-lactic acid. Modified substrates were analyzed by different methods. The elemental composition and the structure of modified poly-L-lactic acid were studied by X-ray Photoelectron Spectroscopy. Surface morphology and roughness was determined using Atomic Force Microscopy. Changes in the surface wettability were determined from the contact angle by goniometry. Possibility of using modified poly-L-lactic acid as the substrate for the bone tissue engineering (cultivation of human osteoblast-like MG 63 cells and human osteoblast Saos-2 cells) or vascular tissue engineering (cultivation of rat vascular smooth muscle cells) was tested by in vitro method. Fluorescence microscopy was used for determination of the number of the adhered and proliferated cells and their morphology.
It was found that the thermal annealing of the deposited PLLA induced the significant changes in the surface morphology and roughness. The new lamellar structure with different-choice parameters was created. The parameters of this structure are strongly dependent on the condition of the deposition. From the cytocompatibility test it is evident that the cells positively react on the presence of the carbon surface. In the case of substrate with carbon layer without thermal stress, cells adhered and proliferated randomly, without arrangement. The cells cultivated on the samples with carbon layer and subsequently thermal stressed exhibited their preferred orientation according to the newly-created nanostructures.
This work was supported by the GACR under project P108/12/G108.