Commercial polyurethanes: The potential influence of auxiliary chemicals on the biodegradation process

Abstract

This investigation elucidates some aspects of auxiliary chemicals on the biodegradation of two commercial polyurethanes (Pellethane and Corethane). The materials were incubated for 28 days with cholesterol esterase and/or with phosphatidylcholine. Extraction studies were carried out on the two materials, using different solvents, chosen on the basis of solvent polarity. FT-IR spectra for the extracted materials indicated the presence of poly(methylene)n oxide moities, silicone oil, bis-ethylene-stearamide, aromatic moities, and alkyd-urea compounds in Pellethane. Corethane materials were shown to contain some fatty acids, hydrocarbon waxes, ester-based species, and chlorinated compounds. Analysis of incubation solutions by high performance liquid chromatography failed to isolate methylene dianiline (MDA) or any of its derivatives from the various polymer incubation solutions. However, a methanol extract of Corethane samples that were incubated for 28 days in cholesterol esterase did show the presence of MDA. The absence of MDA in the Pellethane methanol extracted samples may reflect the differences in surface additives found for this material versus the Corethane. FT-IR/ATR analysis of polymer surfaces exposed to cholesterol esterase/phospholipids mixture showed that there was an increase in the uptake of phospholipids over samples that were incubated in phospholipid dispersion alone. The results of this study show that some of the auxiliary chemicals found in commercial polyurethanes may hinder the specific release of hydrolytic degradation products and delay polymer degradation. However, it should be recognized that the surface layer containing these compounds is susceptible to change following the interaction between the polyurethane-based devices and elements of the host environment (i.e. lipids, enzymes, etc.). Hence, recognition and identification of these changes will ultimately be important in assessing a commercial polymer's blood compatibility characteristics.

Enzyme-induced biodegradation of polycarbonate-polyurethanes: Dependence on hard-segment chemistry

“…There have been very few studies that have investigated the hydrolytic degradation of polycarbonate‐based polyurethanes. In one study by Vermette et al,25 it was found that MDA was released from Corethane after treatment with CE.…”

Enzymatic Synthesis and Chemical Recycling of Poly(carbonate‐urethane)

“…[10] A new class of polycarbonate-based polyurethanes has attracted interest in the field of biomaterials due in part to their mechanical properties similar to those of conventional polyurethanes and to a relatively enhanced hydrolytic stability and oxidative stability. [11][12][13][14][15][16] Recently, it was reported that polycarbonate-based polyurethane materials have a strong sensitivity towards hydrolysis when changes are made to their hard segment content or chemistry or both. [17] In this report, a biodegradable low-molecular weight diurethanediol was combined with the carbonate linkage Summary: Novel enzymatically recyclable poly(carbonateurethane) consisting of a diurethane moiety as a hard segment and a carbonate linkage as an enzymatically cleavable unit was prepared by the polycondensation of biodegradable diurethanediol and diethyl carbonate using lipase.…”

Effect of the content of rigid segments on the properties of polycarbonate urethanes for use in intervertebral disc implants

“…Du¿e znaczenie ma te¿ mo¿liwooeae sterowania w³aoeciwooeciami materia³ów PUR na drodze dobierania substratów oraz parametrów procesu wytwarzania [2]. Unikatowe cechy fizyczne i mechaniczne oraz du¿a biozgodnooeae powoduj¹, ¿e s¹ to jedne z najbardziej atrakcyjnych materia³ów stosowanych w biomedycynie jako: zastawki serca, przewody rozruszników, cewniki, protezy twarzy oraz nooeniki genów [3]. Poliuretany cechuj¹ siê ponadto ma³¹ trombogennooeci¹ oraz korzystn¹ porêcznooeci¹ chirurgiczn¹.…”