title: Enzymatic chain scission kinetics of poly(epsilon-caprolactone) monolayers.
abstract: The hydrolytic and enzymatic degradation behavior of poly(epsilon-caprolactone) (PCL) is investigated using the Langmuir monolayer technique, and an improved data acquisition and data reduction procedure is presented. Hydrolytic and enzymatic monolayer degradation experiments of PCL with various molecular weights by Pseudomonas cepacia lipase have been carried out to analyze the influence of subphase pH, subphase temperature, enzyme concentration, and the packing density of polymer chains on the degradation kinetics. The enzymatic monolayer degradation results in an exponential increase in the number of dissolved degradation fragments with increasing degradation time, which confirms random chain scission to be the dominant scission mechanism. The increase in the enzymatic scission rate constant with decreasing initial average molecular weight of the polymers is assigned to the influence of the area density of polar terminal groups on the substrate-enzyme complex formation.
authors.affiliation: Institute of Physics, University of Potsdam, Am Neuen Palais 10, D-14469 Potsdam, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Kulkarni
authors.forename: J
authors.initials: J
authors.lastname: Reiche
authors.forename: K
authors.initials: K
authors.lastname: Kratz
authors.forename: H
authors.initials: H
authors.lastname: Kamusewitz
authors.forename: I M
authors.initials: IM
authors.lastname: Sokolov
authors.forename: A
authors.initials: A
authors.lastname: Lendlein
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008049:Lipase / Q000737:chemistry / Q000378:metabolism*; D008970:Molecular Weight; D011091:Polyesters / Q000737:chemistry / Q000378:metabolism*; D011549:Pseudomonas / Q000201:enzymology*; D013499:Surface Properties; D013696:Temperature
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; C016240:polycaprolactone; D008049:Lipase