RESUMO
In this study, we modified the surface of bioresorbable electrospun poly-(l-lactic) acid (PLLA) scaffolds by reactive magnetron sputtering of a titanium target under a nitrogen atmosphere. We examined the influence of the plasma treatment time on the structure and properties of electrospun PLLA scaffolds using SEM, XRF, FTIR, XRD, optical goniometry, and mechanical testing. It was observed that the coating formed did not change physicomechanical properties of electrospun PLLA scaffolds and simultaneously, increased their hydrophilicity. No adverse tissue reaction up to 3 months after subcutaneous implantation of the modified scaffolds was detected in in-vivo rat model. The rate of scaffold replacement by the recipient tissue in-vivo was observed to depend on the plasma treatment time.
Assuntos
Materiais Biocompatíveis/farmacologia , Poliésteres/farmacologia , Próteses e Implantes , Gordura Subcutânea/cirurgia , Alicerces Teciduais , Animais , Materiais Biocompatíveis/química , Técnicas Eletroquímicas , Interações Hidrofóbicas e Hidrofílicas , Masculino , Nitrogênio/química , Gases em Plasma/farmacologia , Poliésteres/química , Ratos , Ratos Wistar , Propriedades de Superfície/efeitos dos fármacos , Engenharia TecidualRESUMO
The toxic effect of Al2O3, SiÐ2 and ZrÐ2 nanoparticles on red blood cells of Wistar rats was studied in vitro using the atomic force microscopy and the fluorescence analysis. Transformation of discocytes into echinocytes and spherocytes caused by the metal oxide nanoparticles was revealed. It was shown that only extremely high concentration of the nanoparticles (2mg/ml) allows correct estimating of their effect on the cell morphology. Besides, it was found out that the microviscosity changes of red blood cell membranes treated with nanoparticles began long before morphological modifications of the cells. On the contrary, the negatively charged ZrO2 and SiO2 nanoparticles did not affect ghost microviscosity up to concentrations of 1µg/ml and 0.1mg/ml, correspondingly. In its turn, the positively charged Al2O3 nanoparticles induced structural changes in the lipid bilayer of the red blood cells already at a concentration of 0.05µg/ml. A decrease in microviscosity of the erythrocyte ghosts treated with Al2O3 and SiO2 nanoparticles was shown. It was detected that the interaction of ZrO2 nanoparticles with the cells led to an increase in the membrane microviscosity and cracking of swollen erythrocytes.