Study on the hydrolytic degradation of the segmented GL-b-[GL-co-TMC-co-CL]-b-GL copolymer with application as monofilar surgical suture

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• 作者：Yol ; a M谩rquez ; Lourdes Franco ; Pau Turon ; Alfonso Rodr铆guez-Gal谩n ; Jordi Puiggal铆
• 关键词：Polyglycolide ; Poly(trimethylene carbonate) ; Bioabsorbable surgical sutures ; Hydrolytic degradation ; Polymer microstructure
• 刊名：Polymer Degradation and Stability
• 出版年：December, 2013
• 年：2013
• 卷：98
• 期：12
• 页码：2709-2721
• 全文大小：3757 K

文摘

The hydrolytic degradation of Monosyn鈩? a segmented copolymer derived from glycolide, trimethylene carbonate and 蔚-caprolactone, has been evaluated in buffered aqueous media at different pH and temperature. Degradation processes have been followed by considering mass loss and molecular weight profiles as well as the changes on ¹H NMR and FTIR spectra, morphology and both calorimetric and mechanical properties during exposure to the selected media and temperature.

In all cases, the mass and molecular weight evolutions fitted with first order kinetic processes which were indicative of a random chain scission mechanism. Rate constants were found to strongly depend on temperature and pH. A slight deviation towards a backbiting mechanism was only found in the acid medium at long exposure times when degradation progresses through crystalline domains and recombination of ester groups were probable.

Amorphous and glycolide rich domains were more susceptible to the hydrolytic attack as revealed from mechanical assays and both spectroscopic and calorimetric data. Morphological changes occurring during degradation were highly dependent on pH and indeed different steps affecting the outer (longitudinal cracks) and inner (transversal cracks) parts of sutures could be distinguished. The high content on amorphous soft segments gave rise to well-defined circumferential cracks that affected the inner part of exposed sutures and were interpreted as a consequence of the hydrolytic attack to intralamellar regions.