Cardiovascular biomaterials polymers

Biomaterials for Cardiovascular Devices. Perhaps the most advanced field of biomaterials is that for cardiovascular devices. For several decades bodily parts have been replaced or repaired by direct substitution using natural tissue or selected synthetic materials. The development of implantable-grade synthetic polymers, such as siHcones and polyurethanes, has made possible the development of advanced cardiac assist devices (see... 

ASD Report (2013) Biomaterials Market by Products (Polymers, Metals, Ceramics, Natural Biomaterials) and Applications (Cardiovascular, Orthopedic, Dental,... 

Marketsandmarkets (2012) Bio-Implants Cardiovascular, Spine, Orthopedics, Trauma, Dental Ceramics, Biomaterial, Alloys, Polymers, Allo/Auto/Xenografts, Synthetic. Report code MD-1190, Press release, September 2012. 

This chapter addresses the application of polymeric biomaterials in the context of implantable devices intended for long-term functionality and permanent existence in the recipients. Basic concepts of biocompatibility as well as mechanical and structural compatibility are discussed to provide appropriate background for the understanding of polymer usage in cardiovascular, orthopedic, ophthalmologic, and dental prostheses. Furthermore, emerging classes... 

C.M. Yakacki, R. Shandas, C. I anning, B. Rech, A. Eckstein, K. Gall, Unconstrained recovery characterization of shape-memory polymer networks for cardiovascular appheations. Biomaterials 28 (2007) 2255. 

Yakacki, C.M., Shandas, R., Lanning, C., Rech, B., Eckstein, A., and Gall, K. (2007) Unconstrained recovery characterization of shape-memory polymer networks for cardiovascular applications. Biomaterials, 28, 2255-2263. 

Biomaterials that have been used in the cardiovascular system include processed biological substances, metals, and polymers (see Table 14.1 for typical materials and applications). Materials of biologic origin include structures such as pericardia, arteries and veins, and heart valves. Devices can also include biological substances, e.g., as coatings, such as collagen and heparin. 

Shen, X., Su, F., Dong, J., Fan, Z., Duan, Y., Li, S., 2015. In vitro biocompatibility evaluation of bioresorbable copolymers prepared from L-lactide, 1, 3-trimethylene carbonate, and gly-cobde for cardiovascular appbcations. Journal of Biomaterials Science Polymer Edition 26, 497-514. 

A wide range of polyphosphazenes have been used for a number of biomedical applications. Examples are inert biomaterials for cardiovascular and dental uses, bioerodible and water soluble polymers for controlled drug delivery applications (Allcock et al, 1990). 

Silvestri, A., Seraflni, P.M., Sartori, S., Ferrando, R, Boccafoschi, F., Milione, S., Conzatti, L., Ciardelli, G., 2011. Polyurethane-based biomaterials for shape-adjustable cardiovascular devices. Journal of Applied Polymer Science 122, 3661-3671. 

Brown, P.W. and Constantz, B. 1994. Hydroxyapatite and Related Materials, CRC Press, Boca Raton, FL. Bruck, S.D. 1974. Blood Compatible Synthetic Polymers An Introduction, C.C. Thomas, Springfield, IL. Bruck, S.D. 1980. Properties of Biomaterials in the Physiological Environment, CRC Press, Boca Raton, FL. Chandran, K.B. 1992. Cardiovascular Biomechanics, New York University Press, New York. 

Biomaterials have played a vital role in the treatment of cardiovascular diseases, examples of applications including heart valve prostheses, vascular grafts, stents, indwelling catheters, ventricular assist devices, total implantable artificial heart, pacemakers, automatic internal cardioverter defibrillator, intraaortic balloon pump, and more. A key requirement for materials in cardiovascular applications, particularly blood-contacting devices, is blood compatibility, that is, nonthrombogenic. Additional requirements include mechanical and surface properties that are application specific. Surveying the field of polymers used in cardiovascular applications reveals that PUs, polyethylene terephthalate (PET), and expanded PTFE (ePTFE) are the most commonly used. This section will review each of the three polymers followed by a brief introduction of other emerging polymers for use in the cardiovascular area. 

Diagnostic and therapeutical treatments implicate the contact between tissue, blood and the implanted material. In the cardiovascular field, a variety of biomaterial is implanted in heart and vessels, such as catheters, stents, heart valves and sondes for pacemakers and defibrillators. Using polymers for new technologies has been a revolutionary advance in the therapy of cardiovascular disease [47]. Nevertheless, there is increasing evidence that the polymer coating could be responsible for adverse effects (e.g. in-stent-restenosis, stent thrombosis, chronicle foreign body reactions). Therefore, a feasible biocompatible material should provide a complete re-endothelialisation of the surface, less thrombogenicity as well as anti-inflammatory properties in order to improve clinical outcomes. 

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