Hydrolytic and enzymatic degradation of a poly(ε-caprolactone) network

Abstract

Long-term hydrolytic and enzymatic degradation profiles of poly(ε-caprolactone) (PCL) networks were obtained. The hydrolytic degradation studies were performed in water and phosphate buffer solution (PBS) for 65 weeks. In this case, the degradation rate of PCL networks was faster than previous results in the literature on linear PCL, reaching a weight loss of around 20% in 60 weeks after immersing the samples either in water or PBS conditions. The enzymatic degradation rate in Pseudomonas Lipase for 14 weeks was also studied, with the conclusion being that the degradation profile of PCL networks is lower than for linear PCL, also reaching a 20% weight loss. The weight lost, degree of swelling, and calorimetric and mechanical properties as a function of degradation time were obtained. Furthermore, the morphological changes in the samples were studied carefully through electron microscopy and crystal size through X-ray diffraction. The changes in some properties over the degradation period such as crystallinity, crystal size and Young's modulus were smaller in the case of enzymatic studies, highlighting differences in the degradation mechanism in the two studies, hydrolytic and enzymatic.

Effects of hydroxyapatite filler on long-term hydrolytic degradation of PLLA/PCL porous scaffolds

“…In the degradation studies, phosphate buffer was used instead of phosphate saline buffer in order to avoid salt precipitation onto the samples. In a previous study it was proved that the degradation rate of polyesters was very similar using either water or buffer [38,39], as long as pH is kept constant. The degradation study was conducted using phosphate buffer (3,12g NaH 2 PO 4 and 28.66g de Na 2 HPO 4 per liter, pH=7.4) and 0.02% NaN 3 as an antibacterial and antimicrobial agent.…”

Processing and Properties of PCL/Cotton Linter Compounds

“…PCL is a linear aliphatic semicrystalline polyester, synthesized by ring-opening polymerization of the cyclic lactone in presence of a catalyst. PCL is a polymer with good ductility because of its low glass transition temperature of -60 o C. Due to its biodegradability, biocompatibility and environmental friendliness PCL has been used for packaging, agriculture and medical devices, as well as a substitute of non-biodegradable commodity polymers [7][8][9] . Cotton linter is a widely available, renewable, low cost, and biodegradable reinforcement.…”

Characterization and osteogenic activity of a silicatein/biosilica-coated chitosan-graft-polycaprolactone

“…The diffraction pattern showed the characteristic PCL peaks at 2h of 21.46°and 23.74° (Fig. 1A) that correspond to the (110) and (200) crystallographic planes, respectively [23]. Furthermore, for the CHS sample a broad peak at 2h of 20.15°was observed (Fig.…”

“…The strong reflections presented at 20.23°and 22.01°can be assigned to hydrated crystalline chitosan and those at 21.41°and 23.74°to PCL [30,23]. Consequently, treatment of CHS-g-PCL for 4 weeks with the enzyme lipase, which is known to cause hydrolysis of PCL ester bonds [23], resulted in decreased intensities of the latter peaks (Fig. 1D).…”

“…Crystallinity was also determined of samples that had been incubated for 4 weeks with Pseudomonas sp. lipase (1 mg ml À1 phosphate-buffered saline (PBS), with 0.05 wt.% NaN 3 ; pH 7.4; 37°C) to enzymatically hydrolyze PCL ester bonds [23]. The chemical structure of the CHS-g-PCL sample surfaces was characterized by Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR; Varian 660 spectrometer with Golden Gate ATR accessory; ThermoFisher Scientific, Schwerte, Germany).…”