Papers by Keyword: Elastin-Like Polymer

Abstract: Genetic engineering was used to produce an elastin-like polymer (ELP) with precise amino acid composition, sequence and length, resulting in the absolute control of MW and stereochemistry. A synthetic monomer DNA sequence encoding for (VPAVG)20, was used to build a library of concatemer genes with precise control on sequence and size. The higher molecular weight polymer with 220 repeats of VPAVG was biologically produced in Escherichia coli and purified by hot and cold centrifugation cycles, based on the reversible inverse temperature transition property of ELPs. The use of low cost carbon sources like lactose and glycerol for bacteria cells culture media was explored using Central Composite Design approach allowing optimization of fermentation conditions. Due to its self-assembling behaviour near 33 °C stable spherical microparticles with a size ~ 1µm were obtained, redissolving when a strong undercooling is achieved. The polymer produced showed hysteresis behaviour with thermal absorbing/releasing components depending on the salt concentration of the polymer solution.

Abstract: An elastin-like polymer (ELP) was designed by genetic engineering techniques to mimic the extracellular matrix (ECM). The precise control of the polymer sequence offered many advantages that allowed the definition of distinct and specific domains. The cell attachment domain present in the sequence enhances the cell adhesion. Hexamethylene diisocyanate, a lysine-targeted crosslinker, was used to crosslink the purified polymer. The produced matrices presented an adequate mechanical performance and the morphological analysis by scanning electron microscopy show a homogeneous porous structure, ranging from nanometers to few micrometres. The biological tests will be assessed in future work. These results show the big potential of the ELPs in biomedical applications, especially in the development of systems for tissue engineering and drug release.