RESUMO
Chitosan/poly(DL-lactide-co-glycolide) (Ch/DL PLG) composite scaffolds were fabricated by freeze-drying lyophilization, and were evaluated and compared for use as a bone regeneration scaffold through measurements of the compression mechanical properties of the porous scaffolds. Also, In vitro cell culture of Sprague-Dawley rat's osteoblasts were used to evaluate the phenotype expression of cells in the scaffolds, characterizing the cellular adhesion, proliferation and alkaline phosphatase activity. The gene expression of osteocalcin, sialoprotein, alkaline phosphatase, Type I collagen and TGFß1 were confirmed in the samples; moreover, it was confirmed, the mineralization by IR spectra and EDS analysis. Our results thus show that Ch/DL PLG scaffolds are suitable for biological applications.
Assuntos
Quitosana/química , Teste de Materiais/métodos , Poliglactina 910/química , Engenharia Tecidual/métodos , Fosfatase Alcalina/biossíntese , Fosfatase Alcalina/metabolismo , Animais , Adesão Celular , Proliferação de Células , Colágeno Tipo I/metabolismo , Liofilização , Masculino , Osteoblastos/metabolismo , Osteocalcina/biossíntese , Fenótipo , Ratos , Ratos Sprague-Dawley , Sialoglicoproteínas/biossíntese , Fator de Crescimento Transformador beta1/metabolismoRESUMO
In this work, the effect of the addition of noble metals on the order-order disorder process of the L12 structure corresponding to the intermetallic Ni3Al is analyzed. Stoichiometric, nonstoichiometric, and quasi-binary compositions doped with noble metals such as Ag, Au, Pd, and Pt (1 at%) were analyzed. It was observed that depending on the composition, there is a modification in the activation energies calculated from the two time constants that characterize the disorder process. The statistic of atomic jumps was typified based on the configuration of the window to be crossed and, with this, it was identified that the origin of the negative activation energy of the long disorder process is due to an increase in the corresponding energy of the AlAl-Ni jump through unnatural windows.