Biomaterials specific conductance

Biocompatibility is an essential property of new biomaterials for drug delivery. Biocompatibility is always assessed with respect to specific applications and may be assessed with respect to cytotoxicity, allergic responses, irritation, inflammation, mutagenicity, teratogenicity, and carcinogenicity (Katti el al., 2002). The reviews by Katti et al. (2002) and Domb et al. (1997) provide good discussions on the biocompatibility studies that have been conducted with polyanhydrides over the past two decades. 

In dentistry, silicones are primarily used as dental-impression materials where chemical- and bioinertness are critical, and, thus, thoroughly evaluated.546 The development of a method for the detection of antibodies to silicones has been reviewed,547 as the search for novel silicone biomaterials continues. Thus, aromatic polyamide-silicone resins have been reviewed as a new class of biomaterials.548 In a short review, the comparison of silicones with their major competitor in biomaterials, polyurethanes, has been conducted.549 But silicones are also used in the modification of polyurethanes and other polymers via co-polymerization, formation of IPNs, blending, or functionalization by grafting, affecting both bulk and surface characteristics of the materials, as discussed in the recent reviews.550-552 A number of papers deal specifically with surface modification of silicones for medical applications, as described in a recent reference.555 The role of silicones in biodegradable polyurethane co-polymers,554 and in other hydrolytically degradable co-polymers,555 was recently studied. 

The problems that occur with in vivo experiments are not completely solved. The points where the implanted electrodes cause tissue damage are rapidly regenerated and covered by conjunctive tissue or even by antibodies from electrode rejection. The formation and growth of conjunctive tissue is influenced by the form and nature of the electrode material. A material s biocompatibility is defined as its ability to perform with an appropriate host response in a specific application51. Therefore it is important to develop biomaterials for in vivo sensor applications, since neither the conjunctive tissue nor the antibody layer on the electrode is conducting, and a large decrease in electrode response after implantation is observed. 

The testing conducted on biomaterials intended for use in medical devices must address safety and effectiveness criteria that depend on the intended use as described above as discussed in depth the literature (18, 19). The specific tests required vary with the type of device and application however, some general testing is usually recommended. Normally, animal testing is conducted to demonstrate that a medical device is safe, and when implanted in humans that the device will reduce, alleviate, or eliminate the possibility of adverse medical reactions or conditions (17). 

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