Effect of different γ‐irradiation doses on cytotoxicity and material properties of porous polyether‐urethane polymer

Abstract

Biomaterials respond to sterilization methods differently. Steam sterilization might decrease the performance of thermoplastic polyether-urethane (TPU); however, the effect of different gamma-radiation doses on this polymer is contradictory in present literature. The purpose of this study was to investigate the differences between irradiative doses in comparison with steam sterilization on a porous TPU scaffold produced by a new processing method. No significant differences in the surface chemical structure were found with attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis when comparing with the sterilization methods. The molecular weight (M(w)) had a net increase from 11.5 +/- 0.039 to 13.2 +/- 0.072 kDa by gamma-sterilization from 10 to 60 kGy. The samples that were irradiated (>60 kGy) had also an increase in polydispersity index (PDI; 1.45 +/- 0.007) in comparison with the nonsterile ones (1.31 +/- 0.017), which indicate branching. Liquid chromatography/mass spectroscopy (LC/MS) analysis showed that there was a correlation between the concentration of the breakdown product, methyl dianiline, and cytotoxicity. The concentration of this compound was found to be four times higher in steam-sterilized sample (1.3 +/- 0.01 ppb) compared with that of the polymer sample gamma-sterilized at 10 kGy (0.3 +/- 0.01 ppb). The cytotoxicity of TPU was found to decrease with higher radiation doses, and was significantly higher for the steam-sterilized samples. It is recommended that TPU produced with the described foaming method should be sterilized by gamma-irradiation at 25 kGy or higher doses.

γ-Irradiation of PEGd,lPLA and PEG-PLGA Multiblock Copolymers: I. Effect of Irradiation Doses

“…The influence of radiations on the properties and performances of a polymer differs according to the polymer behaviour in terms of degradation or cross linking, and these phenomena are finally dependent on the specific sensitivity of the material to gamma radiations (9)(10). In order to maintain its desirable properties, each polymer presents a fixed maximum dose of irradiation which is mainly dependent on its own chemical structure (11).…”

The influence of Ag+, Zn2+ and Cu2+ exchanged zeolite on antimicrobial and long term in vitro stability of medical grade polyether polyurethane

“…Furthermore the effect of zeolite content on physical and thermal properties of the polymer was also examined [26,27]. By increasing the silver-zeolite content in the polymer an increased antimicrobial activity was observed (due to the higher silver ion concentration) [22,28] but, depending on the application the zeolite content may influence physical, thermal and/or chemical properties. There are two main reasons to exchange silver as filler in any kind of antimicrobial agent or composite.…”

Prevention of Biofilm Associated Infections and Degradation of Polymeric Materials Used in Biomedical Applications

“…Gamma irradiation has similar influence on the material. Due to the gamma sterilization, branching on polyurethanes (Haugen et al, 2007) and an extremely high rate of oxidation was observed on UHMWPE implants (Bracco et al, 2006, Goldman et al, 1998. During the irradiation, oxygen penetrates into the amorphous region of the polymer where misfit strain is developed.…”