Flexible Bio-Scaffold Analysis Using Mercury Porosimetry

Flexible Bio-Scaffold Analysis Using Mercury Porosimetry

Recent work performed by scientists at Quantachrome UK Ltd, and a leading medical research institute in London has revealed that the two techniques can also provide valuable information, both quantitative and qualitative about the pore structure of a new generation of flexible bio scaffolds being investigated as candidates for arterial replacement. Key attributes of these flexible bio scaffolds are that they must be elastic, as this contributes to the mechanism of pumping blood around the body, and they must be porous to allow growth of endothelial cells inside the artery, and diffusion into the vessel wall.

Mercury intrusion was carried out using Quantachrome PoreMaster 33GT. Three samples were tested to investigate whether minor differences in pore sizes could be detected. The samples are POSS modified polyurethane with different percentages of sodium bicarbonate. The NaHCO3 acts as a porogen which is leached out in water leaving behind the porous structured membrane. The three samples were tested to see the effect of different concentrations of NaHCO3 on the porosity. SEM analysis had previously been performed which showed a very open pore structure and a broad pore size range, but due to the shape and highly porous nature of the material neither the pore size, nor the pore volume could be determined from the images.

The analysis was a blind test, with the operator unaware of the composition of the three samples. A good correlation was shown between the concentration of NaHCO3, and both the pore volume and modal pore size. MIP was able to quantify both the increase in pore volume and the change in pore size which results from increasing concentrations of NaHCO3.