Porous elastic composite scaffolds based on enzymatically synthesized poly(glycerol adipate) and bioglass: the effect of L-lysine diisocyanate content on crosslinking degree and mechanical properties

In this research, poly(glycerol adipate) prepolymer (pPGA) was synthetized using enzymatic polymerization of divinyl adipate (DVA) and glycerol in reaction carried out in the presence of Candida Antarctica enzyme. The pPGA was then solved in 1,4-dioxane and mixed with L-lysine diisocyanate (LDI), bioglass, pourged into mold with sodium chloride, cured and freeze-dried. LDI has a dual function in the system: it is a cross-linking agent and also a bioactive agent that is chemically bound to the scaffold. Three types of porous composite scaffolds having 20 wt.% of bioglass and different cross-linking degree (25, 50 and 100 mol% of LDI) were investigated. The scaffolds were characterized by means of porosity, density, SEM. All tested materials were subjected to a quasi - static compression test. Each material was compressed 10 times. It was shown that the materials exhibited a return to their original shape even with a large compression strain of 90%. An imaging study of the scaffolds before and after compression was conducted using computed tomography (CT). The CT study showed that the resulting materials were not significantly mechanically damaged in the multi - compression process.