Synthesis of chemically crosslinked pullulan/gelatin-based extracellular matrix-mimetic gels

In order to develop pullulan/gelatin-based gels as potential extracellular matrix-mimetic scaffolds, a "one-step" synthesis method using 1,1'‑carbonyldiimidazole (CDI) as activator in DMSO under mild conditions was reported for the first time. Particularly, in contrast to conventional critical requirement of absolute dryness for CDI, it was interesting to find that the formation of gels could be accomplished in the presence of aqueous solvent within a much shorter time, while obtaining improved mechanical properties as demonstrated by compressive tests. UV-Visible spectroscopy, NMR spectrum, TEM and SEM analysis have been employed to evaluate the underlying reaction mechanisms. This method implied that absolute dryness might not be necessary for using CDI as activator in certain cases. This method also represents a new rapid and efficient approach for synthesizing a great variety of chemically crosslinked polysaccharide/protein-based gels as promising material platform potential for tissue engineering and drug delivery applications.