Chapter category: BioMaterials
Biomedical Degradation of Polyurethanes
Biomedical Applications of Polyurethanes
Edited by: Patrick VermetteISBN: 1-58706-023-X
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Chapter authors:
Patrick Vermette, Stéphane Lévesque, and Hans J. G
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As discussed in the preceding Chapter, polyurethanes (PUs) generally show relatively acceptable biological responses, which have frequently led to statements that they are biocompatible. However, many researchers have pointed out a need for improved performance in some applications, such as for some cardiovascular products where currently available materials exhibit excessive protein and platelet adsorption. Secondly, initial expectations of long service life of PU–based devices were frustrated, since another major shortcoming is the degradation that has been reported to occur with PUs in a variety of implant situations. There exist many reports of stress cracking and reduction in performance—in some cases even device failure—from various laboratories, and this situation has led to the withdrawal from the market of some PU–based devices. Pacemakers are a well–known example. These reports have led to a large body of work on how this biomedical degradation of PUs is initiated and progressed, and how it might be overcome. Analysis of the causes and mechanisms of biomedical degradation has proved very challenging, which is not surprising given the enormous complexity of biological environments and the finely tuned, multiple defence mechanisms that the human body has evolved to combat the intrusion of foreign materials.
This Chapter reviews reports on the degradation, both in vivo and as studied by in vitro models, of various commercial and experimental PUs. Also included in this Chapter is discussion of some approaches towards mitigating or overcoming the problem, since many studies describe both the problem and attempts towards a cure. Discussion of synthetic routes towards biostable PUs continues in Chapter 6. Since the performance and stability of polymers is influenced not only by the conditions of the end–use application, but also by the way a polymer has been manufactured, the issue of degradation initiation in the course of the manufacturing process is also discussed.
Additional chapters from this book:
The Future of Polyurethanes
Robert Guidoin and Hans J. Griesser
Where would implantology and the biomedical devices industry be today if it were not for synthetic polymeric biomaterials such as polyurethanes? While "natural" biopolymers such as reconstitut...
Biomedical Applications of Polyurethanes
Mylène Bergeron, Stéphane Lévesque, and Robert Guidoin
Polyurethanes (PUs) represent a very broad family of polymers. They have earned an enviable and irreplaceable position within the medical industry. The applications of PUs are limitless. Ho...
Surface Modification of Polyurethanes
Hans J. Griesser
Why perform surface modification of polyurethanes (PUs) when numerous publications and patents claim "biocompatible" and "blood compatible" PUs? The simple answer is that some claims are exagg...
Developments in Design and Synthesis of Biostable Polyurethanes
Pathiraja A. Gunatillake, Gordon F. Meijs, and Simon J. McCarthy
Synthetic elastomers are frequently the materials of choice for the construction ofimplantable medical device componentry. To function effectively, the chemical and mechanical properties of...
Biomedical Degradation of Polyurethanes
Patrick Vermette, Stéphane Lévesque, and Hans J. G
As discussed in the preceding Chapter, polyurethanes (PUs) generally show relatively acceptable biological responses, which have frequently led to statements that they are biocompatible. Ho...
Biocompatibility of Polyurethanes
Yves Marois and Robert Guidoin
In the last 50 years, the development and the conception of biomaterials used for the construction of prostheses and medical devices has expanded very rapidly. A wide variety of biomaterial...
Additives in Biomedical Polyurethanes
Nathalie Dubé, Sahar Al–Malaika, Gaétan Laroche, and Patrick Vermette
In the preceding Chapter, industrial production of polyurethanes (PUs) was covered. The main industrial processes and sterilization techniques that apply to biomedical polyurethanes were discu...
Commercial Production of Polyurethanes
Stéphane Lévesque, Denis Rodrigue, Patrick Vermette, and Pathiraja Gunatillake
As discussed in the preceding Chapter, polyurethanes (PUs) involve relatively complexchemistry and synthesis procedures compared to other conventional polymers used in biomedical applications....
Synthesis, Physicochemical and Surface Characteristics of Polyurethanes
Martin Castonguay, Jeffrey T. Koberstein, Ze Zhang, and Gaétan Laroche
This Chapter constitutes the starting point that will bring the reader to the other subjects discussed in this book as, for example, the biological response and biostability related to polyure...
