Biomaterials applications

The world of biomaterials is diverse, encompassing ceramics and metals used for orthopedic implants (already discussed in Chapters 2 and 3), to artificial heart valves, blood vessel stents, and contact lenses. This sectiOTi will delve into those biomaterials apphcations that utihze soft polymeric-based materials. 

By definition, biodegradable materials exhibit chemical structures that will decompose under aerobic e.g., composting) and/or anaerobic (e.g., landfill) conditions.Typical degradation byproducts are CO2, CH4, H2O, inorganic compounds e.g., POx, SiOx), or biomass. Whereas degradation refers to the decomposition of a polymer by chemical means e.g., hydrolysis), biodegradation is carried out by the 

Biodegradable polymers should exhibit the following characteristics  

Animal origin Plant origin Microbe origin 

Polyglycolide Poly(s-carpolactone) Acid Polycondensates Poly(L-lactide) Poly(y-butyrolactone) Poly(ethylene succinate) 

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Ratner B D, Chilkoti A and Lopez G P 1990 Plasma deposition and treatment for biomaterial applications... 

An exponential increase of the biomaterials application could be noted in the last years. 

R. Langer and N.A. Peppas reported the main domains of biomaterials application that could be schematically represented in figure 7. 

Figure 7. Repartition of the main domains of biomaterials applications.

Marxer SM, Rothrick AR, Nablo BJ, Robbins ME, Schoenfisch MH. Preparation of nitric oxide (NO)-releasing sol-gels for biomaterial applications. Chemistry of Materials 2003, 15, 4193 1199. 

Because many functional biosystems have mesoscopic dimensions, integration of biocomponents into mesoporous structures should be an interesting research target. Confinement of biomimetic systems in mesoporous media is an important subject when pursued from the view point of biomaterial applications. Incorporation of biomaterials such as proteins,98 99 amino acids,100 and vitamins101 have been investigated... 

Calcium oxide is the main ingredient in conventional portland cements. Since limestone is the most abundant mineral in nature, it has been easy to produce portland cement at a low cost. The high solubility of calcium oxide makes it difficult to produce phosphate-based cements. However, calcium oxide can be converted to compounds such as silicates, aluminates, or even hydrophosphates, which then can be used in an acid-base reaction with phosphate, forming CBPCs. The cost of phosphates and conversion to the correct mineral forms add to the manufacturing cost, and hence calcium phosphate cements are more expensive than conventional cements. For this reason, their use has been largely limited to dental and other biomedical applications. Calcium phosphate cements have found application as structural materials, but only when wollastonite is used as an admixture in magnesium phosphate cements. Because calcium phosphates are also bone minerals, they are indispensable in biomaterial applications and hence form a class of useful CBPCs that cannot be substituted by any other. 

The surface is a crucially important factor of biomaterial, and without an appropriate biocompatibility the biomaterial could not function. On the other hand, the bulk properties of materials are equally important in the use of biomaterials. An opaque material cannot be used in vision correction, and soft flexible materials cannot be used in bone reinforcement. The probability of finding a material that fulfills all requirements in physical and chemical bulk properties for a biomaterial application and whose surface properties are just right for a specific application is very close to zero, if not absolutely zero. From this point of view, all biomaterials should be surface treated to cope with the biocompatibility. However, if the surface treatment alters the bulk properties, it defeats the purpose. In this sense, tunable LCVD nanofilm coating that causes the minimal effect on the bulk material is the best tool available in the domain of biomaterials. 

Ciarkowski AA. Preclinical testing evaluation of biomaterials in vitro and in vivo. In Handbook of Biomaterials Applications, von Recum AP, ed. 1986. Macmillan Publishing Co., New York. Ch. 42. 

These studies provide a base for further development of collagen materials for specific biomaterial applications. Further studies are being directed to the effect of collagen film on blood in terms of platelet and white cell adhesion, protein absorption, and thrombogenicity. 

Figure 1 Structures of polymers commonly used in biomaterials applications PGA (I), PLA (2), PAAs (3), linear PEI (4), PAMAMs (5) and chitosan (6) (see text for abbreviations)...

The threading acrylate-terminated PEO copolymers used in these hydrogels preparation include PCL-PEO-PCL triblock polymer [96], PLA-PEO-PLA triblock polymer [97], 4-arm PEO star polymer [98], and PCL-Pluronic-PCL block polymer [100], Particularly for those formed from biodegradable block copolymers as the threading polymers, the hydrogels may be of interest in biomaterials applications because of their potential biodegradability. 

Vandenberg, E.J. Tian, D. A new, crystalline high melting bis(hydroxymethyl)- polycarbonate and its acetone ketal for biomaterial applications. Macromolecules 1999, 32 (11), 3613-3619. 

Journal of Biomaterials Applications. London Sage Publications. ISSN 0885-3282. Articles emphasize development, manufacture and clinical applications, and compatibility of biomaterials. Peer-reviewed. 

Saito N, Usui Y, Aoki K et al (2009) Carbon nanotubes biomaterial applications. Chem Soc Rev 38 1897-1903... 

Braatz, J.A. 1994. Biocompatible polyurethane-based hydrogels. Journal of Biomaterials Applications 9(1) 71-96. 

Kim, K.H., Narayanan, R., and Rautray, T.R. (2013) Surface Modification of Titanium for Biomaterial Applications, Biomaterials-Properties, Production and Devices, Nova... 

Ratner B D, Chilkoti A and Lopez G P 1990 Plasma deposition and treatment for biomaterial applications Plasma Deposition, Treatment and Etching of Polymers ed R d Agostino (Boston, MA Academic) pp 463-516... 

Acknowledgement Authors would like to acknowledge the Biomaterials Applications of Memphis (BAM) Research Lahoratories at the University of Memphis-University of Tennessee Health Science Center for assistance in preparing work. 

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