Enhanced hydration stability of Bombyx mori silk fibroin/PEG 600 composite scaffolds for tissue engineering

Silk fibroin scaffolds obtained via regeneration by Ajisawa's reagent (CaCl2/H2O/EtOH, mole ratio 1:8:2) and freeze-drying followed by steam sterilization resulted unstable when incubated in physiological medium over 1-month period since the oxygen diffusivity and mechanical resistance to compression significantly decreased. Blending of regenerated silk fibroin with PEG 600 lead to a novel scaffold with an improved water stability. Multi-parameter characterization has revealed that scaffolds made by composite material were stable in physiological media over at least 1month of incubation. Interestingly, the presence of PEG has a notable impact on wettability and protein adsorption. This increase in hydrophilicity could be beneficial for initial cell adhesion and survival as well as for the adsorptive loading of growth factors.