A simple and reproducible approach to characterize protein stability using rheology.

As the utility of proteins in medical diagnosis and therapy becomes more fully realized, interest in characterizing proteins' stability continues to increase. This paper reports the merits of rheology as an approach to characterizing the stability of a model protein, immunoglobulin (IgG). A controlled-strain rotational rheometer equipped with parallel plates geometry was used to measure changes in the viscosity of an IgG buffer solution during a programmed temperature ramp.

Comprehensive characterization of the effect of tissue storage conditions on tissue-adhesive interaction.

In the evaluation of tissue adhesives, freshly harvested tissues are the most relevant to clinical application; however, it is difficult to obtain and test experimental samples immediately following surgery. The aim of the present investigation is to elucidate the effect of storage conditions on the ability of preserved tissue samples to mimic freshly harvested tissue. Porcine small intestine was used as a model tissue for the experiments.

Thermal stability and melt rheology of poly(p-dioxanone).

Melt viscosities of poly(p-dioxanone) (PPDO) samples having different molecular weights were studied using a controlled-strain rotational rheometer under a nitrogen atmosphere. First, PPDO's thermal stability was evaluated by recording changes in its viscosity with time. The result, that samples' viscosities decreased with time when heated, demonstrated that PPDO is thermally unstable: its degradation activation energy, obtained by using a modified MacCallum equation, was a relatively low 71.