Effects of block length on the enzymatic degradation and erosion of oxazoline linked poly--caprolactone

详细信息    查看全文

• 作者：Mika Pulkkinen ; Minna Malin ; Tommy Tarvainen ; Tiina Saarimä ; ki ; Jukka Seppä ; lä ; ; Kristiina Jä ; rvinen
• 关键词：Biodegradation ; Surface erosion ; Degradation ; Enzyme ; Polycaprolactone
• 刊名：European Journal of Pharmaceutical Sciences
• 出版年：2007
• 出版时间：June 2007
• 年：2007
• 卷：31
• 期：2
• 页码：119-128
• 全文大小：1470 K

文摘

The aim of the study was to develop enzyme sensitive polymers for pharmaceutical applications. Thus, 2,2′-bis(2-oxazoline)-linked poly--caprolactone (PCL-O) polymers were synthesized by using -caprolactone precursors with different molecular weights (M_n: 1500, 3900, 7500 and 12,000 g/mol), and the effects of PCL block length on enzymatic degradation and erosion (weight loss) of PCL-O films were studied. Solvent cast PCL and PCL-O films were incubated (22 days) in the presence of pancreatin (1 % , pH 7.5), with and without enzyme inhibitors. In the absence of enzyme inhibitors, surface erosion of the PCL-O films occurred during incubation, and the erosion of the PCL-O films increased in parallel with a decrease in the PCL block length. The presence of the lipase inhibitors, paraoxon-ethyl and tetrahydrolipstatin delayed the weight loss of the PCL-O films. These results indicate that lipase was mainly responsible for the enzymatic erosion of the PCL-O films. In comparison, practically no weight loss of the PCL or the PCL-O films was observed in phosphate buffer (pH 7.4) (28 days incubation). The results demonstrate that the studied -caprolactone based poly(ester-amide)s are enzyme sensitive polymers whose erosion rate can be controlled by the PCL block length.