| 초록 |
It has attracted a great deal of attention as a biocompatiable, biodegradable, and bioresorbable biomaterial. l-lactic acid is recycled by conversion to glycogen in the liver, while d-lactic acid is most probably excreated through the kidneys unchanged. In biomedical applications, mostly l-poly(lactide) (l-PLA) and dl-poly(lactide) have been studied. With high mechanical strength and toughness, semi-crystalline l-PLA has been used in orthopaedic devices. Since Ikeda et al.found stereocomplexation between enantiomeric (l-PLAand d-PLA, numerous studies have been performed for the crystallization, physical properties, crystal structure of the stereocomplex. In stereocomplexation crystallities formed as a result of stereocomplexation , equimolar l- and d-lactide unit sequences are packed side by side while l- and d- unit sequences can also crystallize separately. In this study, we have investigated in vitro the alkaline hydrolysis of enantiomeric mixtures from l-PLA and d-PLA at the air/water interface. It was founded that the hydrolysis rate of stereocomplexed-mixture monolayers from l-PLA and d-PLA was much lower than those of their homopolymers. The retardation of hydrolysis is mainly due to strong interaction between l- and d-lactide unit sequences, which prevents the penetration of water into the bulk. |
