Mechanical properties and biocompatibility of melt processed, self-reinforced ultrahigh molecular weight polyethylene

Yan-Fei Huang; Jia-Zhuang Xu; Jian-Shu Li; Ben-Xiang He; Ling Xu; Zhong-Ming Li

doi:10.1016/j.biomaterials.2014.04.077

Mechanical properties and biocompatibility of melt processed, self-reinforced ultrahigh molecular weight polyethylene

Biomaterials. 2014 Aug;35(25):6687-97. doi: 10.1016/j.biomaterials.2014.04.077. Epub 2014 May 15.

Authors

Yan-Fei Huang¹, Jia-Zhuang Xu¹, Jian-Shu Li², Ben-Xiang He³, Ling Xu⁴, Zhong-Ming Li⁵

Affiliations

¹ State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering and, Sichuan University, Chengdu 610065, People's Republic of China.
² Department of Biomedical Engineering, College of Polymer Science and Engineering and, Sichuan University, Chengdu 610065, People's Republic of China.
³ Rehabilitation Centre, Sport Hospital Attached to Chengdu Sport University, 251 Wuhou Temple Street, Chengdu 610041, People's Republic of China.
⁴ State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering and, Sichuan University, Chengdu 610065, People's Republic of China. Electronic address: xulingshannon@gmail.com.
⁵ State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering and, Sichuan University, Chengdu 610065, People's Republic of China. Electronic address: zmli@scu.edu.cn.

PMID: 24835044
DOI: 10.1016/j.biomaterials.2014.04.077

Abstract

The low efficiency of fabrication of ultrahigh molecular weight polyethylene (UHMWPE)-based artificial knee joint implants is a bottleneck problem because of its extremely high melt viscosity. We prepared melt processable UHMWPE (MP-UHMWPE) by addition of 9.8 wt% ultralow molecular weight polyethylene (ULMWPE) as a flow accelerator. More importantly, an intense shear flow was applied during injection molding of MP-UHMWPE, which on one hand, promoted the self-diffusion of UHMWPE chains, thus effectively reducing the structural defects; on the other hand, increased the overall crystallinity and induced the formation of self-reinforcing superstructure, i.e., interlocked shish-kebabs and oriented lamellae. Aside from the good biocompatibility, and the superior fatigue and wear resistance to the compression-molded UHMWPE, the injection-molded MP-UHMWPE exhibits a noteworthy enhancement in tensile properties and impact strength, where the yield strength increases to 46.3 ± 4.4 MPa with an increment of 128.0%, the ultimate tensile strength and Young's modulus rise remarkably up to 65.5 ± 5.0 MPa and 1248.7 ± 45.3 MPa, respectively, and the impact strength reaches 90.6 kJ/m(2). These results suggested such melt processed and self-reinforced UHMWPE parts hold a great application promise for use of knee joint implants, particularly for younger and more active patients. Our work sets up a new method to fabricate high-performance UHMWPE implants by tailoring the superstructure during thermoplastic processing.

Keywords: Artificial joints; Flow accelerator; Melt processing; Self-reinforcement; Ultrahigh molecular weight polyethylene.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Biocompatible Materials / chemistry*
Calorimetry, Differential Scanning
Cell Line
Cell Survival / drug effects
Knee Prosthesis*
Mechanical Phenomena
Mice
Polyethylenes / chemistry*
Surface Properties
Tensile Strength / physiology
X-Ray Diffraction

Substances

Biocompatible Materials
Polyethylenes
ultra-high molecular weight polyethylene