During the past few years, the production of biodegradable polymeric materials from renewable sources has gained extended attention in both academic and industrial fields. It is a promising approach to solve a number of problems connected with increasing pollution and energy shortage caused by the petroleum consumption. Focusing on this eco-friendly approach, aliphatic polyesters are of great interest due to their wide spectrum of potential applications and sustainability. Among this group segmented block copolymers exhibit a broad range of advantageous features as they can be produced using monomers from biomass feedstock. These copolymers consist of different types of sequences with different properties and distinct transition temperatures, thus being capable of forming hard and soft segments. Hard segments are responsible for the dimensional, thermal and mechanical stability of the polymer while the soft segments are designed to impart the elasticity to the polymer. Herein, biodegradable poly(butylene succinate-co-dilinoleic succinate) (PBS-DLS) copolymers with 70:30 (wt%) ratio of hard to soft segments were successfully synthesized using Candida antarctica lipase B (CAL-B) as a biocatalyst. During two-step synthesis in diphenyl ether, biobased succinate was polymerized with renewable 1,4 – butanediol and dimer linoleic diol to obtain “green” copolyesters as sustainable alternative to petroleum-based materials. Structure-properties relationships were discussed by investigating the number average molecular weight, chemical structure, crystalline behavior and thermal transition temperatures. Moreover, cytotoxicity test using mouse fibroblast cells L929 were performed on extracts of obtained PBS-DLS materials indicating excellent biocompatibility in vitro.
I cannot get it from Figure 4. Thanks a lot
The conclusion that material is not toxic was obtained from the resazurin viability assay. Living cells maintain a reducing environment within their cytoplasm and mitochondria, in which resazurin (blue and non-fluorescent) is reduced by a dehydrogenase to form the red fluorescent dye - resorufin. The amount of resorufin can be monitored by measuring fluorescence which is proportional to the number of living cells. The number of living cells in the presence of extracts from the given materials is compared to the number of cells without the presence of the extract from the tested materials. On this basis, the normalized cell viability was calculated.
Segmented block copolymers exhibit a broad range of advantageous features and they can be produced using monomers from biomass feedstock. These copolymers consist of different types of sequences with different properties and distinct transition temperatures, thus being capable of forming hard and soft segments. Hard segments are designed to impart dimensional, thermal and mechanical stability to the polymer and soft segments are responsible for the elastomeric. With appropriate selection of these building blocks it is possible to obtain biobased materials with a wide range of potential applications such as packaging, fibers, scaffolds and drug delivery systems.
