Characteristics and Cell Growth Behavior of Gelatin/Polyvinyl Alcohol Porous Scaffolds

Gelatin/polyvinyl alcohol (PVA) (g/P) porous scaffolds with a glutaraldehyde/g ratio of 3 were synthesized by freeze/thaw and lyophilization to evaluate the effect of the g/P ratio (10/0 to 7/3) on the mechanical properties and cell growth behavior of the scaffolds. Fourier transform infrared spectroscopy results showed that the g/P scaffolds exhibited good crosslinking between gelatin and gelatin (imine), PVA and PVA (acetal group), and gelatin and PVA (imine). The pore size decreased gradually from 170±63 μm, to 140±60 μm, 129±64 μm, and 74 ±23 μm by varying the g/P ratio from 10/0, to 9/1, 8/2, and 7/3, respectively. As the g/P ratio was changed from 10/0 to 7/3, the compressive strength and swelling rate increased gradually from 150± 17 kPa to 290 ±28 kPa and 1268± 11% to 1640 ±35%, respectively. Among the scaffolds, 7/3 g/P scaffolds with tailored properties are suitable for wound healing.

Dinuclear lanthanide–lithium complexes based on fluorinated β-diketonate with acetal group: magnetism and effect of crystal packing on mechanoluminescence

A convenient and straightforward synthesis of a novel type of Ln–Li β-diketonates with a discrete molecular structure is presented.

Two New Phytoecdysteroids from the Needles of Taxus canadensis

Two new phytoecdysteroids with a 20,22-acetal group were identified for the first time from the needles of the Canadian yew, Taxus canadensis. Their structures were characterized as ponasterone A 20,22-p-hydroxybenzylidene acetal (1) and ponasterone A 20,22-acetonide (2) on the basis of 1D, 2D NMR evidence and high-resolution FABMS analysis