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Enzymatic Degradation of Poly( L ‐lactide) and Poly( ε ‐caprolactone) Electrospun Fibers
Author(s) -
Zeng Jing,
Chen Xuesi,
Liang Qizhi,
Xu Xiuling,
Jing Xiabin
Publication year - 2004
Publication title -
macromolecular bioscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.924
H-Index - 105
eISSN - 1616-5195
pISSN - 1616-5187
DOI - 10.1002/mabi.200400092
Subject(s) - crystallinity , lipase , cationic polymerization , caprolactone , pulmonary surfactant , polymer chemistry , electrospinning , chemistry , differential scanning calorimetry , enzymatic hydrolysis , hydrolysis , degradation (telecommunications) , chemical engineering , polymer , materials science , organic chemistry , enzyme , copolymer , biochemistry , telecommunications , physics , computer science , thermodynamics , engineering , crystallography
Summary: Poly( L ‐lactide) (PLLA) and poly( ε ‐caprolactone) (PCL) ultrafine fibers were prepared by electrospinning. The influence of cationic and anionic surfactants on their enzymatic degradation behavior was investigated by measuring weight loss, molecular weight, crystallinity, and melting temperature of the fibers as a function of degradation time. Under the catalysis of proteinase K, the PLLA fibers containing the anionic surfactant sodium docecyl sulfate (SDS) exhibited a faster degradation rate than those containing cationic surfactant triethylbenzylammonium chloride (TEBAC), indicating that surface electric charge on the fibers is a critical factor for an enzymatic degradation. Similarly, TEBAC‐containing PCL fibers exhibited a 47% weight loss within 8.5 h whereas SDS‐containing PCL fibers showed little degradation in the presence of lipase PS. By analyzing the charge status of proteinase K and lipase PS under the experimental conditions, the importance of the surface charges of the fibers and their interactions with the charges on the enzymes were revealed. Consequently, a “two‐step” degradation mechanism was proposed: (1) the enzyme approaches the fiber surface; (2) the enzyme initiates hydrolysis of the polymer. By means of differential scanning calorimetry and wide‐angle X‐ray diffraction, the crystallinity and orientation changes in the PLLA and PCL fibers during the enzymatic degradation were investigated, respectively.SEM photographs of PCL‐TEBAC fiber samples before and after enzymatic degradation (2.75 h) at 37 °C.