The effects on polyetheretherketone and polyethersulfone of electron and γ irradiation

PEEK biomaterials in trauma, orthopedic, and spinal implants

“…Furthermore, even though free radicals are generated during irradiation of PEEK, they rapidly decay, likely due to recombination reactions made possible by the mobility of electrons along the molecular chain [68]. In studies of free radical decay using electron spin resonance (ESR), Li et al [68] found no evidence of residual free radicals in PEEK immediately after exposure with up to 600 kGy of gamma radiation, indicating that any free radicals produced by irradiation of PEEK have a lifetime of less than 20 minutes, which was the time needed to transfer the samples from the irradiation chamber to the ESR instrument in their experiment.…”

Clinical application of triangular parabolic PEEK mesh with hole button produced by combining CAD, FEM and 3DP into cranioplasty

“…Rivard et al implanted PEEK fusion device in the rabbit's intervertebral space for a biocompatibility test, and found out that there no adverse consequences such as tissue necrosis, nerve swelling, fat dissolution, border wear and others in 1, 4, 12 weeks after the operation and inflammation cell responses were absorbed after 12 weeks. His study also supported that fibrous tissue and blood vessels can climb in the PEEK fuse [19]. Torchrick et al porous PEEK mesh cell culture experiments also showed consistent results: porous PEEK mesh can promote cell proliferation, bone growth and angiogenesis, improve bone integration, of which integration effect is better than titanium mesh's [21].…”

“…Due to the attenuation of the rays of titanium repair, it will result in some pseudo shadow in the CT and X-ray image. HM Li and others utilized electron spin resonance to study free radical attenuation of PEEK and discovered that there's no radical 20 min after radiation (600 kGray) on PEEK, so PEEK was not considered a secondary radiation source after gamma-ray sterilization [19,20]. PEEK has outstanding advantages on the biocompatibility, no toxin, no immunity, no allergens.…”

A comparative study of radiation effects in medical-grade polymers: UHMWPE, PCU and PEEK

“…In PEEK, production of short-lived radicals has been reported (Sasuga and Hagiwara, 1987;Vaughan and Sutton, 1994); their rapid decay is likely due to recombination reactions caused by the mobility of electrons along the molecular chain. In studies of free radical decay using electron spin resonance (ESR), Li et al (1993) found no evidence of free radicals in PEEK immediately after exposure with up to 600 kGy of gamma radiation and suggested that any free radicals produced by irradiation had a lifetime of less than 20 min, which was the time needed to transfer the samples from the irradiation chamber to the ESR instrument in their experiment. In a recent study, Awaja et al (2012) detected free radicals in plasma-treated PEEK at room temperature with a lifetime of approximately 24 h. From the viewpoint of molecular structure, it is known that aliphatic polymers, including polyolefins such as UHMWPE, are susceptible to bond cleavage during irradiation, leading to the generation of long-lived macro radicals.…”

“…PEEK is reportedly a radiation resistant polymer and, unlike UHMWPE, can be a good candidate for radiation sterilization (Joyce et al, 2006). A summary of studies providing evidence of PEEK and PCU as joint replacement materials, listed in the references sections, are Joyce et al (2006), Kelsey et al (1997), Khan et al (2005), Kraft et al (2011), Kurtz et al (2010), Li, et al (1993, Quigley (2002), and Toth et al (2006).…”