Fabrication of porous 3-D structure from poly(l-lactide)-based nano-composite foams. Effect of foam structure on enzymatic degradation

Polylactide/Clay Nano-Biocomposites

“…At the same time, a small increase in c appears due to the preferential enzymatic degradation in the restricted amorphous region, leaving a crystalline residue. This is in agreement with the characteristics of enzymatic degradation of bulk PLA [58,62,63], i.e., a sample weight loss without molecular weight decrease.…”

“…For both bulk and neat PLA, the degradation rate slightly decreases with increasing initial c in the range of 0-30 % and abruptly decreases beyond 30 %. The dispersed MMT layers have almost no effect on the acceleration of the degradation rate with the nano-composite bulk and in the foam state This observation suggests that the linear degradation rate of the foams is affected by the initial value of , c as well as PLA nano-composite (and neat PLA) degradation [58]. The enzymatic hydrolysis of PLLA matrix proceeds preferentially at disordered amorphous region on the sample surface rather than on the restricted amorphous domains, which are located between the crystalline lamellae in the spherulites [62].…”

“…The biodegraded nano-composite foam provide a porous 3-D scaffold and the pore size is determined by controlling the degradation time using proteinase-K as an effective degrading catalyst [57,58]. The enzymatic degradation of PLLA in the presence of proteinase-K, which is extracted from protease in a fungus called Tritirachium album in 1974 [59].…”

“…The nanocelluar takes up large amount of water compared with that of microcellular, which leads to the swelling of the foam, and thus facilitate the enzymatic degradation of matrix PLA as compared with the bulk sample. The content of absorbed water greatly determines the enzymatic degradability [58]. Figure 4.27 shows the surface and the cross-section morphologies of the microcellular with , c = 16.9 % (Fig.…”

Advances in Biomimetic and Nanostructured Biohybrid Materials

“…PLA-clay nanocomposite foams that have different cell density (nanocellular and microcellular) are more susceptible to enzymatic degradation by the action of proteinase-K than both the bulk nanocomposite and the neat PLA. [124] Organically modified layered titanates are employed simultaneously as nanofillers and as photocatalysts to increase the mechanical properties of PLA and to accelerate the bionanocomposite degradation under the action of sunlight. [121] The addition of nanofiller particles to the biopolymer matrix also gives rise to 'tortuous' pathways that make gas diffusion through the bionanohybrid films difficult.…”