A novel ultra high molecular weight polyethylene–hyaluronan microcomposite for use in total joint replacements. II. Mechanical and tribological property evaluation

Abstract

The mechanical and tribological properties of a new biomaterial, an ultra high molecular weight polyethylene-hyaluronan (UHMWPE-HA) microcomposite, were investigated in this article, which is Part II of a two-part study. Part I presented the synthesis and physical/chemical characterization of the novel microcomposites. The microcomposite was developed for bearing surfaces of total joint replacements and was designed to enhance lubrication and improve wear resistance compared to noncrosslinked UHMWPE. Pin-on-flat wear tests with cross-path motion demonstrated significant decreases for both the wear and wear rate of UHMWPE with the presence of hyaluronan (HA) within and on the microcomposite. Compared to noncrosslinked UHMWPE, a maximum decrease of 56% in wear and a maximum decrease of 31% in wear rate were observed at 1.0 million cycles. Inferior tensile properties were observed for the microcomposites when compared to noncrosslinked UHMWPE, which resulted from poor intermolecular entanglement of the UHMWPE caused by low remolding temperature throughout microcomposite manufacturing. Similar results were observed for the sham control, which was processed in the same way as the microcomposite, except for the addition of HA.

Hemocompatibility and Hemodynamics of Novel Hyaluronan–Polyethylene Materials for Flexible Heart Valve Leaflets

“…The details of hydrolysis are described in detail elsewhere. 44 Briefly, hydrolysis was performed by three successive 60 min ultrasonic baths in 0.2 M NaCl solution (H 2 O:ethyl alcohol, 1:1) at 45 °C, followed by 60 min of additional ultrasonication in pure 0.2 M NaCl aqueous solution without ethyl alcohol, then washed twice in 3:2 H 2 O:ethyl alcohol solutions (first 2 h, then 30 min), then dehydrated in acetone for 60 min, and finally dried under vacuum at 50 °C until no change in weight was observed.…”

“…21,43 This enhanced polymer is highly hydrophilic, with the strength and durability of UHMWPE. 42,44 In vitro hip simulator tests to 5 million cycles and in vivo (goat knee) studies to 12 months have shown BioPoly implants to be very durable—with no signs of wear, mechanical deterioration, calcification or HA loss. 21 …”

Improved wear resistance of orthopaedic UHMWPE by reinforcement with zirconium particles

“…Much of this research has looked into using fillers in UHMWPE specifically for improving its performance in artificial joints. This includes the addition of naturally found biomaterials for increased biocompatibility [11,12], and the inclusion of polydimethylsiloxane for increased ductility [13]. The recent interest in nanotechnology has led to the addition of many different nanoparticles such as carbon nanotubes [14][15][16], and nanoclay platelets, both for increased strength and stiffness [17].…”

Surface modification of ultrahigh molecular weight polyethylene by plasma‐induced in‐situ grafting with vinyl triethoxysilane

“…However, its low surface energy and chemical inertness make it hard to wet sufficiently or react with other materials, which is disadvantageous to its application in some cases . For example, the joint replacements based on UHMWPE do not enjoy the low friction and wear of natural joints due to the extreme hydrophobicity of UHMWPE, and the blood compatibility of UHMWPE is not satisfying owing to its inert and hydrophobic surface when used as blood‐contacting material . Thus, it has been a hot topic to improve the surface property of UHMWPE to enhance its interaction with the biological environment …”