Suture materials mechanical properties

Artificial Soft Biologies. In addition to sutures, polymers are used for a number of biomedical applications, as illustrated in Figure 5.128. Polymers used for hard structural applications such as dentures and bones are presented in this figure, but will be described in the next section. In this section, we will concentrate on polymers for soft biological material applications and will limit the description to mechanical properties as much as possible. 

Biodegradable materials were initially used in medical applications such as sutures, prostheses, controlled drug-release systems, and vascular grafts. These applications are enabled by their biocompatibility, their ability to be absorbed by the body, and because of their mechanical properties appropriate for such applications [6]. 

This chapter contains three case studies. The first one on climbing rope illustrates the technology of fibre production and rope construction to meet specific mechanical property targets. There are some similarities between rope and the much smaller scale braided sutures used in surgery. Further sport case studies, on polymer foam protective gear and materials in running shoes, are mentioned in the Further Reading section. 

Poly(vinyl alcohol) (PVA) is one of the hydrogels most often used in biomaterial applications. Because of the presence of excessive hydroxyl groups, PVA contained a significant amount of water. PVA was also claimed to have good mechanical strength. Another hydrogel, poly(2-hydroxyethyl methacrylate) (poly-HEMA), is well known for its excellent biocompatibility. xhe versatile biomedical applications of poly-HEMA are demonstrated by its uses in contact lenses, vitreous humor replacements and suture materials. To explore a new formulation and other usages of these two pol ers, we have copolymerized HEMA with PVA-MA (PVA esterified with maleic anhydride), the preparation and properties of this copolymer are discussed in this article. 

Because textile materials are lightweight, flexible and strong polymers and biological tissues are themselves fibrous polymers, with very similar dimensional, physical and mechanical properties, they have found numerous applications as bioimplants. From their use as sutures and ligatures many thousands of years ago, to hernia repair meshes and vascular grafts in the present century, textiles continue to be explored for use in newer and better performing medical products. The currently available implants can be categorized as one-, two- or three-dimensional structures. 

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