PLLA와 PEG의 공중합에 의한 가소화 효과와 플라즈마처리에 의한 미생물합성 폴리에스테르의 효소분해성

Abstract

Biodegradable polymers have had practical medical applications as dissolvable sutures and matrices for drug delivery, but high-volume consumable plastics continue to be dominated by petroleum-based materials. Two factors have recently made biodegradable polymers economically attractive. These are (i) rising costs of petroleum production resulting from the depletion of the most easily accessible reserves and (ii) environmental and economic concerns associated with waste disposal. However, a desired property of biodegradable polymer sometimes cannot be obtained by itself. In this study, we were forced to improve this mechanical properties by modifications. In order to have processibility, various poly(ethylene glycol)-polylactide (PEG-PLA) block copolymers were synthesized and blended with PLLA because of softness of PEG. The results showed that mechanical properties of blends can be changed by adding a block copolymer. Since the enzymatic degradation of microbial poly(hydroxylalkanoate)s (PHAs), such as poly[(R)-3-hydroxybutyrate] and poly[(R)-3-hydroxybutyrate-co-3-hydroxyvalerate] initially occurs by a surface erosion process, their degradation behaviors can be controlled by the change of surface property. In order to control the rate of enzymatic degradation, plasma modification technique was applied the surfa to changece property of microbial PHAs. The surface hydrophobic and hydrophilic properties of PHA films were introduced by CF3H and O2 plasma exposures, respectively. The enzymatic degradation was carried out at 37 C in 0.1 M potassium phosphate buffer (pH 7.4) in the presence of an extracellular PHB depolymerase purified from Alcaligenes facalis T1. The results showed that the significant retardation of initial enzymatic erosion of CF3H plasma-treated PHAs was observed due to the hydrophobicity and the enzyme inactivity of the fluorinated surface layers while the erosion rate of O2 plasma-treated PHAs was not accelerated.