Regular paper Biocatalytic synthesis of δ-gluconolactone and ε-caprolactone copolymers*

• Main Authors: Anamaria Todea, Valentin Badea, Lajos Nagy, Sándor Kéki, Carmen G. Boeriu, Francisc Péter
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Key words; ε-caprolactone; d-gluconolactone; lipases; biopolymers; Antarc*; Antarctica
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.456.4195; http://www.actabp.pl/pdf/Preprint/2013_646.pdf

The biodegradability and biocompatibility properties of ε-caprolactone homopolymers place it as a valuable raw material, particularly for controlled drug delivery and tis-sue engineering applications. However, the usefulness of such materials is limited by their low hydrophilicity and slow biodegradation rate. In order to improve polycapro-lactone properties and functionalities, copolymerization of ε-caprolactone with δ-gluconolactone was investigat-ed. Since enzymatic reactions involving sugars are usu-ally hindered by the low solubility of these compounds in common organic solvents, finding the best reaction medium was a major objective of this research. The op-timal copolymerization conditions were set up by using different organic media (solvent and solvents mixtures), as well as solvent free systems that are able to dissolve (completely or partially) sugars, and are nontoxic for en-zymes. Native and immobilized lipases by different im-mobilization techniques from Candida antarctica B and Thermomyces lanuginosus have been used as biocata-lyst at 80°C. Although the main copolymer amount was synthesized in DMSO:t-BuOH (20:80) medium, the high-est polymerization degrees, up to 16 for the copolymer product, were achieved in solventless conditions. The products, cyclic and linear polyesters, have been char-acterized by FT-IR and MALDI-TOF MS analysis. The re-action product analysis revealed the formation of cyclic products that could be the major impediment of further increase of the chain length.