Bio-mimetic study of novel materials for joint replacements
- PDF / 439,363 Bytes
- 8 Pages / 612 x 792 pts (letter) Page_size
- 89 Downloads / 304 Views
0898-L05-19.1
Bio-mimetic study of novel materials for joint replacements
R. Ribeiro1, P. Ganguly2, D. Darensbourg2, M. Usta3, A.H. Ucisik4 and H. Liang1 1 Mechanical Engineering Department, MS 3123, Texas A&M University, College Station, TX77843 2 Department of Chemistry, Texas A&M University, PO Box 30012, College Station, TX 778423012 3 Gebze Institute of Technology, Department of Materials Science and Engineering, 41400 Gebze/Kocaeli-Turkey 4 Bogazici University, Institute of Biomedical Engineering, Department of Prostheses, Materials and Artificial Organs, 80815, Bebek/Istanbul-Turkey
ABSTRACT Polytrimethylene carbonate (PTMC) and poly ε-caprolactone are conventional biodegradable, biocompatible polymers. Their friction response against cartilage and surface attraction forces were studied toward using them as artificial cartilage materials. Their behavior was compared to that of natural cartilage and a conventional joint replacement material, ultrahigh molecular weight polyethylene. It was possible to polymerize these materials using a calcium based catalyst. Simulated body fluid (SBF) was used as lubricant between surfaces in the friction tests. It was found that higher surface attractive forces on a silicon tip AFM related to lower friction coefficients. This confirs the fact that hydrophilic surfaces enhance the effectiveness of boundary lubrication of simulated body fluid. PTMC and PTMC-ε-caprolactone co-polymer showed lower hydrophilicity and higher friction coefficients and need to be modified in order to bring them closer in behavior to natural cartilage.
INTRODUCTION Total joint replacement (TJR) has for long been the most successful method of treating an arthritic joint. TJR’s however don’t last more than 10 – 15 years [1]. The cartilage, being avascular, does not have an inherent healing capacity. In a TJR part of the joint on either side (which includes the cartilage and subchondral bone) are removed by surgery. In their place, an artificial prosthesis is implanted into the bone. The articulating surfaces are subject to friction forces which lead to the formation of wear debris. Over a period of time, this wear debris tends to cause loosening of the prosthesis by interfering with the bone-prostheses interface and also causes a negative immune response from the body leading to osteolysis [2]. The widely used materials in joint replacement are ultrahigh molecular weight polyethylene (UHMWPE, which usually forms a bearing surface) and polished metal or ceramic which forms the part that is subject to greater mechanical loading [3]. It is the wear particles from UHMWPE which are the major cause of joint replacement failure [4]. Oka et al. [5] have attempted to develop an artificial articular cartilage material using polyvinyl alcohol hydrogel (PVA-H). The PVA-H was attached to the underlying bone using a titanium fiber mesh (TFM) that acted as an artificial porous bone [6]. There was bone ingrowth
0898-L05-19.2
into the TFM onto which the PVA-H was injected forming a composite osteochondral device.
Data Loading...
