Our colleague Amanda Barnes, now at the University of York, has recently published a paper demonstrating the incorporation of poly(NIPAM) into collagen hydrogels. The paper has just been accepted at Biomacromolecules.
There is a lack of hydrogel materials whose properties can be tuned at the point of use. Biological hydrogels such as collagen, gelate at physiological temperature, however they are not always ideal as scaffolds due to their low mechanical strength. Their mechanics can be improved through cross linking and chemical modification, but these methods still require further synthesis. We have demonstrated that by combining collagen with a thermoresponsive polymer, poly(N-isopropylacrylamide) (PNIPAM), the mechanical properties can be improved while maintaining cytocompatibility. Furthermore, different concentrations of this polymer, led to a range of hydrogels with shear moduli ranging from 105 Pa down to less than 102 Pa, similar to the soft tissues in the body. In addition to variable mechanical properties, the hydrogel blends have a range of micron scale structures and porosities, which caused adipose-derived stromal cells (ADSCs) to adopt different morphologies when encapsulated within, and may therefore be able to direct cell fate.
The full paper can be found at Biomacromolecules.