title: Biocatalyzed approach for the surface functionalization of poly(L-lactic acid) films using hydrolytic enzymes.
abstract: Poly(lactic acid) as a biodegradable thermoplastic polyester has received increasing attention. This renewable polyester has found applications in a wide range of products such as food packaging, textiles and biomedical devices. Its major drawbacks are poor toughness, slow degradation rate and lack of reactive side-chain groups. An enzymatic process for the grafting of carboxylic acids onto the surface of poly(L-lactic acid) (PLLA) films was developed using Candida antarctica lipase B as a catalyst. Enzymatic hydrolysis of the PLLA film using Humicola insolens cutinase in order to increase the number of hydroxyl and carboxylic groups on the outer polymer chains for grafting was also assessed and showed a change of water contact angle from 74.6 to 33.1° while the roughness and waviness were an order of magnitude higher in comparison to the blank. Surface functionalization was demonstrated using two different techniques, (14) C-radiochemical analysis and X-ray photoelectron spectroscopy (XPS) using (14) C-butyric acid sodium salt and 4,4,4-trifluorobutyric acid as model molecules, respectively. XPS analysis showed that 4,4,4-trifluorobutyric acid was enzymatically coupled based on an increase of the fluor content from 0.19 to 0.40%. The presented (14) C-radiochemical analyses are consistent with the XPS data indicating the potential of enzymatic functionalization in different reaction conditions.
authors.affiliation: University of Natural Resources and Life Sciences, Institute for Environmental Biotechnology, Tulln, Austria.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pellis
authors.affiliation: Austrian Centre of Industrial Biotechnology GmbH, Tulln, Austria. enrique.herreroacero@acib.at.
authors.forename: Enrique Herrero
authors.initials: EH
authors.lastname: Acero
authors.affiliation: Graz University of Technology, Institute of Organic Chemistry, Graz, Austria.
authors.forename: Hansjoerg
authors.initials: H
authors.lastname: Weber
authors.affiliation: University of Natural Resources and Life Sciences, Institute of Wood Technology and Renewable Resources, Tulln, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Obersriebnig
authors.affiliation: Graz University of Technology, Institute of Organic Chemistry, Graz, Austria.
authors.forename: Rolf
authors.initials: R
authors.lastname: Breinbauer
authors.affiliation: Vienna University of Technology, Institute of Chemical Engineering, Vienna, Austria.
authors.forename: Ewald
authors.initials: E
authors.lastname: Srebotnik
authors.affiliation: University of Natural Resources and Life Sciences, Institute for Environmental Biotechnology, Tulln, Austria.|Austrian Centre of Industrial Biotechnology GmbH, Tulln, Austria.
authors.forename: Georg M
authors.initials: GM
authors.lastname: Guebitz
mesh_terms: D001709:Biotechnology / Q000379:methods*; D002250:Carbon Radioisotopes / Q000032:analysis / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism*; D019344:Lactic Acid / Q000737:chemistry* / Q000378:metabolism*; D008049:Lipase / Q000378:metabolism*; D056951:Photoelectron Spectroscopy; D011091:Polyesters; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism*; D013499:Surface Properties
chemical_list: D002250:Carbon Radioisotopes; D005656:Fungal Proteins; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D008049:Lipase; C431349:lipase B, Candida antarctica
keywords: 14C-radiochemical analysis; Candida antarctica lipase B; Enzymatic polymer functionalization; Surface functionalization