Enhanced oxidation stability of highly cross-linked ultrahigh molecular weight polyethylene by tea polyphenols for total joint implants

et al. 2021

Polymers

Background: the wear of tibial insert is still one of primary factors leading to failure of total knee arthroplasty (TKA). Dodecyl gallate (DG) has shown improvements in the oxidation stability of highly cross-linked polyethylene (HXLPE). This study aimed to assess the application of HXLPE supplemented with DG (HXLPE-DG) on the tibial insert in TKA concerning the wear resistance and the potential impact on implant fixation; Methods: tibial inserts made of HXLPE-DG were subjected to a 3 million loading-cycle wear test following ISO 14243-1:2009. The loss of mass and wear rate of the tibial inserts were calculated. The quantity, size,- and shape of wear particles were recorded; Results: the test specimens lost an average mass of 16.00 mg ± 0.94 mg, and were on an average wear rate of 3.92 mg/million cycles ± 0.19 mg/million cycles. The content of wear particles in the calf serum medium was 3.94 × 108 particles/mL ± 3.93 × 107 particles/mL, 96.66% ± 0.77% of the particles had an equivalent circular diameter less than 0.5 μm. The aspect ratio of wear particles was 1.40 (min: 1.01; max: 6.42). Conclusions: HXLPE-DG displayed advantages over the commonly used materials for tibial inserts and presented the potential of application in TKA.

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Wear Assessment of Tibial Inserts Made of Highly Cross-Linked Polyethylene Supplemented with Dodecyl Gallate in the Total Knee Arthroplasty

Zhang

et al. 2021

Polymers

“…To resist complex biochemical environment, it is imperative to develop UHMWPE implants with initiative antioxidant performance. Stabilizing UHMWPE by antioxidants (such as vitamin E) has been historically proposed and adopted as an alternative method to avoid loss in mechanical properties caused by remelting. , On the basis of the current finding, the clinical significance of using antioxidants also contributes to the lasting protection of UHMWPE implants against humoral attack in vivo. − It is encouraging to find that other types of antioxidants have also been introduced to stabilize UHMWPE such as hindered amine light stabilizers and polyphenols. − More efforts should be directed toward assessing their oxidation stability in vivo.…”

Section: Discussionmentioning

confidence: 99%

Insights into Oxidation of the Ultrahigh Molecular Weight Polyethylene Artificial Joint Related to Lipid Peroxidation

Ren

Wei

et al. 2019

ACS Appl. Bio Mater.

Self Cite

Oxidative degradation of ultrahigh molecular weight polyethylene (UHMWPE) bearings is one of the main factors that deteriorates their mechanical properties and abrasive wear resistance, which further results in the failure of total joint replacements. Absorption and diffusion of synovial fluids have been considered as causes of the oxidation of UHMWPE bearings. However, the role of synovial fluids in oxidation of UHMWPE remains elusive. In this work, we aimed to reveal the oxidation mechanism of UHMWPE joints with respect to squalene (a representative component of the synovial fluid). The UHMWPE doped in squalene showed slight oxidation, while severe oxidation was observed when squalene doped UHMWPE was exposed to oxygen atmosphere. Squalene manifested lipid peroxidation with notable oxidation products and oxygen-derived free radicals during thermo-oxidative aging. Lipid peroxidation was deduced to follow two routes including autoxidation and thermal oxidation. The aggressive free radicals of squalene abstracted hydrogen atoms from the UHMWPE chains, initiating the oxidation of UHMWPE artificial joints. These findings not only provide evidence for comprehending the process of squalene-induced UHMWPE oxidation but also are instructive to develop highly oxidative-resistant UHMWPE.

“…Although remelting can eliminate free radicals, employing antioxidants to stabilize UHMWPE has been receiving increasing levels of attention in recent years. − As the analysis of retrieved implants indicated that UHMWPE oxidized through humoral attack in vivo, antioxidants are strongly backed up to achieve the long-term oxidation stability of highly crosslinked UHMWPE. , The α-tocopherol, also dubbed vitamin E (VE), is an exemplary success to protect UHMWPE implants from oxidation. , As a typical hindered phenol antioxidant, it neutralizes the radical of UHMWPE by donating a proton from the phenolic hydroxyl group. The residual phenoxy radical could isomerize into a tocopherol-benzyl radical and then reacts with another free radical of UHMWPE, forming a grafting structure. , However, it points to the vulnerability that VE attacks the crosslink precursors to hinder the crosslinking of UHMWPE.…”

Section: Introductionmentioning

confidence: 99%

Polyphenol-Assisted Chemical Crosslinking: A New Strategy to Achieve Highly Crosslinked, Antioxidative, and Antibacterial Ultrahigh-Molecular-Weight Polyethylene for Total Joint Replacement

Ren

ACS Biomater. Sci. Eng.

Lan

et al. 2020

Self Cite

Highly crosslinked ultrahigh-molecular-weight polyethylene (UHMWPE) bearings are wear-resistant to reduce aseptic loosening but are susceptible to oxidize in vivo/in vitro, as reported in clinical studies. Despite widespread acceptance of antioxidants in preventing oxidation, the crosslinking efficiency of UHMWPE is severely impacted by antioxidants, the use of which was trapped in a trace amount. Herein, we proposed a new strategy of polyphenol-assisted chemical crosslinking to facilitate the formation of a crosslinking network in high-loaded tea polyphenol/UHMWPE blends. Epigallocatechin gallate (EGCG), a representative of tea polyphenol, was mixed with UHMWPE and peroxide. Multiple reactive phenolic hydroxyl groups of tea polyphenol coupled with the nearby free radicals to form extra crosslinking sites. The crosslinking efficiency was remarkably enhanced with increasing tea polyphenol content, even at a concentration of 8 wt %. Given by the hydrogen donation principle, the high-loaded tea polyphenol also enhanced the oxidation stability of the crosslinked UHMWPE. The antioxidative performance was preserved even after tea polyphenol elution. Moreover, superior antibacterial performance was achieved by the in situ tea polyphenol release from the interconnected pathways in the present design. The strategy of polyphenol-assisted chemical crosslinking is applicable for producing highly crosslinked, antioxidative, and antibacterial UHMWPE, which has promising prospects in clinical applications.