Implants and Tissue Engineering

The field of metal-catalyzed copolymerization of oxetanes and C02 will continue to flourish, due not only to the versatility of the reaction but also to the aliphatic polycarbonate products being important components of thermoplastic elastomers that, in turn, have huge potential in medical applications such as sutures, drug-delivery systems, body, and dental implants, and tissue engineering. The exploration of other oxetane monomers (Figure 8.17) such as 3,3-dimethyloxetane and 3-methoxymethyl-3-methyloxetane, will surely provide a multitude of applications... 

Volume 550— Biomedical Materials—Drug Delivery, Implants and Tissue Engineering,... 

Zhou T, Braunhut SJ, Medeiros D, Marx KA (1999) In Mater Res Soc Symp biomedical materials drug delivery, implants and tissue engineering. Materials Research Society Pittsburgh PA 550 177... 

Since PLA is a widely spread material for implants and tissue engineering scaffolds, surface functionalization is an important measure to improve the rather poor device-tissue interaction profile of this material. A few, more or less easy, methods for nonpermanent surface modification of PLA have been developed such as coating with proteins or entrapment of other polymers applying a swelling/entrapment/contraction cycle. However, for... 

Conductive polymer nanocomposites may also be used in different electrical applications such as the electrodes of batteries or display devices. Linseed oil-based poly(urethane amide)/nanostuctured poly(l-naphthylamine) nanocomposites can be used as antistatic and anticorrosive protective coating materials. Castor oil modified polyurethane/ nanohydroxyapatite nanocomposites have the potential for use in biomedical implants and tissue engineering. Mesua ferrea and sunflower seed oil-based HBPU/silver nanocomposites have been found suitable for use as antibacterial catheters, although more thorough work remains to be done in this field. ° Sunflower oil modified HBPU/silver nanocomposites also have considerable potential as heterogeneous catalysts for the reduction of nitro-compounds to amino compounds. Castor oil-based polyurethane/ epoxy/clay nanocomposites can be used as lubricants to reduce friction and wear. HBPU of castor oil and MWCNT nanocomposites possesses good shape memory properties and therefore could be used in smart materials. ... 

Gao, Y., in Biomedical Materials Drug Delivery, Implants and Tissue Engineering, Neenan, T., Marcolongo, M., Valentini, R. F., eds. Wairendale, Pa. Materials Research Society, 1999, pp. 361-366. 

BiomateriaiS. Biomaterials find important application as medical implants and tissue engineering substrates. In each case, clinical or scientific effectiveness strongly depends on the behavior of interfacial biomolecules. Other articles in this encyclopedia discuss various aspects of biomaterials. In this section, important aspects dealing with adsorbed biomolecules are briefly presented. 

This definition was, in 2003, further revised using the subgroups of long-term implants, short-term implants, and tissue engineered products [3]. 

D printing has also been used to produce medical implants and tissue engineering constructs involving biocompatible and bioresorbable scaffolds. Skowyra... 

Laurencin C T, Ambrosio A M A, Borden M D and Cooper Jr J A, Tissue engineering orthop)edrc applications , Ann. Rev. Biomed. Eng., 1999, 1, 19-46. Laurencin C T, Ko F K, Borden M D, Cooper Jr J A, Li W J and Attawia M A, Fiber based tissue engineered scaffolds for musculoskeletal applications in vitro cellular response . In Biomedical Materials - Drug Delivery, Implants and Tissue Engineering, ed. T Neenan, M Marcolongo and R F Valentini, Materials Research Society, Warrendale, USA, 1999, 550, 127-35. 

Principal therapies for bone defects and injuries include bone-tissue transplantation, artificial prosthesis implantation and tissue-engineering treatments. Autologous transplantation of cells and tissue is the gold standard (Healy and Guldberg, 2007). The scarcity of autologous tissue, however, limits its further application (Healy and Guldberg, 2007). Therefore, much effort has been put into the development of other approaches. 

Stock et al. used P4HB scaffolds and tissue engineered the patch with a porosity of 95% and pore sizes in the range of 180-240 p,m by salt-leaching and solvent evaporation. The sheep autologous cells (endothelial, smooth muscle, and fibroblast cells) were seeded on the scaffold before implantation. Results confirmed that the cell-seeded implants induced progressive tissue regeneration with no thrombus formation, stenosis, or dilatation. 

In the future, nanotubes and nanofibers can be administered systemically, if the problem of their toxicity is addressed, for example, by appropriate polymer coating. In this respect, the continuous nanofibers are more likely to be used in implants or tissue engineering applications. 

K. Ito, Y. Yamada, T. NaiM, M. Ueda, Simultaneous implant placement and bone regeneration around dental implants using tissue-engineered bone with fibrin glue, mesenchymal stem cells and platelet-rich plasma, Clin. Oral Implants Res. 17 (2006) 579-586. 

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