AIM: To study the effects of propofol on plasma membrane fluidity in PC12 cells and liposome,and its relevant mechanism. METHODS: Fluorescence depolarization method was used to measure values of fluorescence anisotropy, fluorescence polarization as well as microviscosity in PC12 cells and microviscosity in liposome continuously for 30 min. RESULTS: Propofol induced a significant decrease of fluorescence anisotropy, fluorescence polarization as well as microviscosity in PC12 cells, particularly in the first 5 min. After 5 min, the values of anisotropy were remained lower levels. Although propofol at concentration of 1 mg?L -1 had no effects on microviscosity in liposome, porpofol at concentration of 10 mg?L -1 and 100 mg?L -1 significantly decreased microviscosity in liposome. CONCLUTION: Propofol can significantly increase membrane fluidity in PC12 cells and liposome in a concertration dependent manner, and the anesthetic effect of propofol may be resulted from changes of membrane fluidity and structure of neurocyte.

The porous foams were prepared by the solvent-casting and particulate-leaching technique using poly(DL-lactide) (PDLLA), poly(DL-lactide)/hydroxyapatite (PDLLA/20wt%HA), and poly(DL-lactide)/beta-tricalcium phosphate(PDLLA/20wt% beta-TCP) respectively. Observations by scanning electron microscopy indicated that the HA and beta-TCP were homogeneously dispersed in the polymer matrix, and the pores of the foams are interconnected, resulting in continuous pore structures. The porosity of PDLLA/HA and PDLLA/beta-TCP foams was lower than that of the pure PDLLA foams, but the compression strength was higher than that of the pure PDLLA foams. The results of the degradation in vitro showed that both HA and beta-TCP had significant inhibitory effects on the degradation of PDLLA, especially the HA. It is expected that the composite foams are of use as scaffolds for bone tissue engineering.
Biocompatible Materials ; chemistry ; Bone Substitutes ; chemical synthesis ; chemistry ; Calcium Phosphates ; chemical synthesis ; chemistry ; Durapatite ; chemical synthesis ; chemistry ; Polyesters ; chemical synthesis ; chemistry ; Polymers ; chemistry ; Porosity ; Tissue Engineering