Medical implants structures

The ability to synthesize carbon nanostmctures, such as fullerenes, carbon nanotubes, nanodiamond, and mesoporous carbon functionalize their surface or assemble them into three-dimensional networks has opened new avenues for material design. Carbon nanostructures possess tunable optical, electrical, or mechanical properties, making them ideal candidates for numerous applications ranging from composite structures and chemical sensors to electronic devices and medical implants. 

Biofilms can form on just about any imaginable surface metals, plastics, natural materials (such as rocks), medical implants, kitchen coimters, contact lenses, the walls of a hot tub or swimming pool, hmnan and animal tissue, etc. Indeed, wherever the combination of moisture, nutrients, and a surface exists, biofilms will likely be foimd as well. Biofilms are characterized by structural heterogeneity, genetic diversity, complex community interactions, and an extracellular matrix of pol)uneric substances. Biofilms are an important link in the energy budget of many natural commimities. Both types of cells produce a pol)uneric extracellular slime layer which encloses the cells. This complex aggregate of cells and polysaccharide is the biofilm community. 

J. Lahann, D. Klee, and H. HOcker. CVD-polymerization of a functionalized poly(p-xylylene). a generally applicable method for the immobilization of drugs on medical implants Materialwiss. Werkstofflech., 30 763-766,1999. S. Y. Park, J. Blackwell, S. N. Chvalun, A. A. Nikolaev, K. A. MaUyan, A. V. Pebalk, and I. E. Kardash. The structure of poly(cyano-p-xylylene). Polymer, 41(8) 2937-2945, April 2000. 

Since USM mills can be used on these multipurpose milling machines, the micro milling process is considered a flexible manufacturing process. In addition, the process is characterized by low setup costs, unlimited part materials, and a high material removal rate (Ozel et al. 2011). It is, for example, used to machine small features in molds used for mass production (e.g., microfluidic devices), to structure medical implants for better biocompatibility, to generate deep x-ray lithography masks, and to manufacture prototypes rapidly as well as efficiently (Aurich et al. 2012). 

Huang Z M, Zhang Y Z, Kotaki M and Ramakrishna S (2003), A review on polymer nanoflbers by electrospinning applications in nanocomposites . Compos Sci Tech, 63(15), 2223-2253. DOI 10.1016/80266-3538(03)00178-7. ZUberman M (2007), Novel composite fiber structures to provide drug/pro-tein dehvery for medical implants and tissue regeneration , Acfa Biomater, 3(1), 51-57 DOI 10.1016/j.actbio.2006.06.008. 

Polyhydroxyalkanoates (PHA) is a family of structurally diverse biopolyesters accumulated by many bacteria as carbon and energy source (Figure 16.1)d PHA have been exploited with a series of applications including environmentally friendly biodegradable plastics for packaging purposes, biofuels, medical implants, and recently, smart materials. PHA monomers are also produced as chiral intermediates for medical or fine chemical applications. ... 

However, not only the choice of material has to be considered for medical implants. Also the architecture of the textile structure plays a crucial role not only determining mechanical properties and how successful the implant is from a mechanical, load-bearing point of view but also the durability and long-term properties acting as a replacement tissue and successfully fulfilling the physiological function in the body. 

Zilberman, M., 2007. Novel composite fiber structures to provide drug/protein delivery for medical implants and tissue regeneration. Acta Biomaterialia 3, 51—57. 

This example of vascular grafts devices points out the evolution of fibrous implantable medical devices and highlights the great potential offered by each scale level of fibrous structures for biocompatibility improvements. Fibers as well as whole fibrous stmctures should be considered as implantable devices that have inherent abilities to interact with the biological environment at each of the three predetermined scale levels. Study of characteristics and specificities of fibers, fibrous siuface, and fibrous volume should then provide a more forward-looking approach in the textile substitute s area for design and achievement of smart medical implantable textile devices. 

Tyrosine is the only major, natural nutrient containing an aromatic hydroxyl group. Derivatives of tyrosine dipeptide can be regarded as diphenols and may be employed as replacements for the industrially used diphenols such as Bisphenol A in the design of medical implant materials (Kigime 1). The observation that aromatic backbone structures can significantly increase the stiffness and mechanical strength of polymers prowded the rationale for the use of tyrosine dipeptides as monomers. 

Tyrosine-derived polyarylates offer the ability to alter wdely the polymeric properties by changes in either the backbone or the pendent chain structure. These polymers appear most adept at addressing medical implant needs where a slowly degrading, relatively flexible and soft polymer is required. 

Silver, F.H., Kato, Y.P., Ohno, M. and Wasserman, A.J. (1992) Analysis of inannnalion connective tissue Relationship between hierarchical structures and mechanical properties./. Long-Term Effects of Medical Implants, 2, 165-198. 

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