Surface Modification of Ultra-High Molecular Weight Polyethylene with Crosslinked Hyaluronic Acid and its Antiwear Performance

2015 ◽  
Vol 642 ◽  
pp. 94-98
Author(s):  
Chau Chang Chou ◽  
Yu Hsiang Hao ◽  
Fu Yin Hsu

The surface of high-pressure crystallized ultra-high molecular weight polyethylene (UHMWPE) was modified for application as an artificial cartilage material. A UHMWPE surface pretreated by a series of processes, including treatment with O2-plasma and ethylenediamine solution, was coated with hyaluronic acid (HA). After that, adipic acid dihydrazide (AAD) was added to partially crosslink the HA coating in order to enhance its durability. The modified samples were verified by water contact angle measurement and Fourier transform infrared spectrometry. Both HA layers, original and crosslinked, were also quantitatively evaluated by carbohydrate chemistry assay according to the absorbance of the incident light. The tribological performance of the samples was evaluated by a pin-on-disk test rig lubricated by normal saline under an average pressure of 18 MPa and at a sliding speed of 0.03 m/s for 45 h. The wear resistance of the HA-coated UHMWPE specimens promoted by the crosslink process was superior to that of the original HA-coated sample, and that resistance was maintained after immersion in saline solution for one month.

2008 ◽  
Vol 62 (6) ◽  
Author(s):  
Jindřiška Bočková ◽  
Lucy Vojtová ◽  
Radek Přikryl ◽  
Jan Čechal ◽  
Josef Jančář

AbstractA novel material for hard tissue implants has been prepared. The ultra-high molecular weight polyethylene (UHMWPE) was grafted with collagen I, to improve its biocompatibility with soft tissue in case of its usage in bone engineering. Before collagen immobilization, commercial grade UHMWPE was treated with air plasma to introduce hydroperoxides onto the surface and subsequently grafted with carboxylic acid to functionalize the surface. Acrylic acid and itaconic acid were used for surface functionalization. After graft polymerization of carboxylic acids, collagen was immobilized covalently through the amide bonds between residual amino and carboxyl groups in the presence of water-soluble carbodiimide/hydroxysuccinimide cross-linking system. Each step of modification was characterized using spectroscopic (EPR, ATR-FTIR, and XPS), microscopic (SEM and CLSM), and contact angle measurement methods. The experimental results showed that plasma treatment led to a generation of free radicals on the UHMWPE surface resulting in the formation of unstable hydroperoxides. These reactive species were used to graft unsaturated carboxylic acids onto UHMWPE. Consequently, collagen was grafted via the-NH2 and-COOH reaction. The obtained experimental data along with microscopic observations confirmed the success of graft poly-merization of itaconic as well as of acrylic acid and collagen immobilization onto the UHMWPE surface.


2021 ◽  
Vol 11 (4) ◽  
pp. 1703
Author(s):  
Jack Turicek ◽  
Nicole Ratts ◽  
Matey Kaltchev ◽  
Nazieh Masoud

Ultra-high molecular weight polyethylene (UHMWPE) is one of the most commonly used polymers in joint replacements because of its biologically inert properties and low friction coefficient. However, it has downfalls relating to its wear, adhesion, and lubrication. In this study, UHMWPE samples were treated with a tubular helium cold atmospheric pressure (CAP) plasma source in order to improve three properties of the polymer: (1) its wear resistance, which was characterized by durometer hardness, (2) its lubrication characterized by water contact angle, and (3) its adhesion characterized by both root mean square surface roughness (Rq) and water contact angle. The polymer was treated by two different parts of the plasma plume (the base and the tip) at two different helium flow rates (1 L/min and 2.5 L/min), for different treatment times. Results of the plasma treatment showed a decrease in the contact angle of between 32 and 54 degrees, a significant increase in the roughness by up to 10 times the pristine surface, and no substantial change in the hardness. These improvements to the adhesion and lubrication properties of the polymer examined suggest that the treated surface could be more suitable for use in artificial joints.


1998 ◽  
Vol 550 ◽  
Author(s):  
C.M. Klapperich ◽  
K. Komvopoulos ◽  
L. Pruitt

AbstractUltra-high molecular weight polyethylene (UHMWPE) is the principal material used to replace damaged cartilage in total joint replacement surgeries. This publication presents preliminary results from a new class of surface treatments to modify the surface chemistry and microstructure of UHMWPE under controlled processing conditions. Radio frequency plasmas were used to lightly crosslink the subsurface of UHMWPE and to modify the surface chemical state through the attachment of low-surface-energy fluorocarbon groups. A pin-on-disk apparatus was used to slide CoCrWNi pins with spherical tips on polished disks of plasma- treated and untreated UHMWPE immersed in a bath of preserved bovine serum. The wear resistance and surface chemical composition of tested specimens were characterized by surface profilometry and X-ray photoelectron spectroscopy (XPS), respectively. Changes in the surface hydrophobicity due to plasma treatment were evaluated using contact angle measurements. The prospect of surface plasma treatment in orthopedic applications is elucidated in the context of the obtained friction, wear, distilled water contact angle, and XPS results.


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