Controlled bacteriostasis of tea polyphenol loaded ultrahigh molecular weight polyethylene with high crosslink density and oxidation resistance for total joint replacement

Novel Synthesis Approach for Natural Tea Polyphenol-Integrated Hydroxyapatite

Hydroxyapatite (HAP) has garnered considerable interest in biomedical engineering for its diverse applications. Yet, the synthesis of HAP integrated with functional natural organic components remains an area ripe for exploration. This study innovatively utilizes the versatile properties of tea polyphenol (TP) to synthesize HAP nanomaterials with superior crystallinity and distinct morphologies, notably rod-like structures, via a chemical deposition process in a nitrogen atmosphere. This method ensures an enhanced integration of TP, as confirmed by thermogravimetric (TGA) analysis and a variety of microscopy techniques, which also reveal the dependence of TP content and crystallinity on the synthesis method employed. The research significantly impacts the field by demonstrating how synthesis conditions can alter material properties. It leads the way in employing TP-modified nano-HAP particles for biomedical applications. The findings of this study are crucial as they open avenues for the future development of tailored HAP nanomaterials, aiming at specific medical applications and advancements in nanotechnology.

Improved oxidation stability and crosslink density of chemically crosslinked ultrahigh molecular weight polyethylene using the antioxidant synergy for artificial joints

Vitamin E (VE) is currently an approved antioxidant to improve the oxidation stability of highly crosslinked ultrahigh molecular weight polyethylene (UHMWPE) insert used commercially in total joint arthroplasty. However, the decrease in crosslink density caused by VE reduces wear resistance of UHMWPE, showing an uncoordinated challenge. In this work, we hypothesized that D-sorbitol (DS) as a secondary antioxidant can improve the antioxidant efficacy of VE on chemically crosslinked UHMWPE. The combined effect of VE and DS on oxidation stability of UHMWPE was investigated at a set of controlled hybrid antioxidant content. The hybrid antioxidant strategy showed significantly synergistic enhancement on the oxidation stability of chemically crosslinked UHMWPE compared with the single VE strategy. More strikingly, the crosslink density of the blends with hybrid antioxidants stayed at a high level since DS is not sensitive to crosslinking. The relationships between oxidation stability, mechanical properties, crosslink density, and crystallinity were investigated, by which the clinically relevant overall performance of UHMWPE was optimized. This work provides a leading-edge design mean for the development of joint bearings.

A super-hydrophilic partially reduced graphene oxide membrane with improved stability and antibacterial properties

In order to improve stability and antibacterial property, a novel super-hydrophilic partially reduced graphene oxide membrane was prepared by interfacial polymerization of piperazine and partially reduced graphene oxide as aqueous solution and trimesoyl chloride as organic solution. Fourier transform infrared spectroscopy, scanning electron microscope, and contact angle measurement were conducted to probe the morphology and properties of the membranes. The modified membrane possessed super-hydrophilicity, improved durability and swelling resistance. The optimized membrane had a molecular weight cut off of about 674 Da and possessed a pure water permeability of 49.86 L·m^-2·h^-1·MPa^-1. The retention order of salts was Na₂SO₄ > MgSO₄ > MgCl₂ > Na₂CO₃ > CaCl₂ > NaCl, while the rejection for four kinds of pharmaceuticals followed the order of ibuprofen (92%) > carbamazepine (87%) > amlodipine (80%) > atenolol (76%), indicating that the negatively charged membrane could improve the retention performance by the electrostatic repulsive effect. Moreover, the enhanced antibacterial performance of membrane attributed to the dual effects of the super-hydrophilicity and the tea polyphenols antibacterial material loading, which may alter the charge distribution on and within the membrane, leading to loss of cell viability.