Biodegradation research need

Despite the universal use of sutures for wound closure, there is a need to utilize adhesives instead, because of their ease of use and the reduced risk of infection. Alkyl cyanoacrylate adhesives have been studied extensively for this use, and a significant amount of research has been performed to evaluate their interaction with living tissue [40,41 J. They have been approved for external use only, because of concerns with the fact that the polymers do not readily biodegrade and can cause inflammation around the area to which it was applied. However, these concerns are reduced for -butyl cyanoacrylate, as compared to the ethyl cyanoacrylate. There is even some evidence that their use as liquid sutures actually reduces the rate of infection around the healing wound or surgical incision [42J. 

These environmental issues, created a dire need for the development of green polymeric materials, which would not involve the use of toxic and noxious component in their manufacture and could be degradable in nature. For these reasons, through the world today, the development of biodegradable materials with controlled properties has been a subject of great research challenge for the community of material scientists and engineers. 

The fungal treatment showed a high efficiency, by completely removing the estrogens (El, E2, and E3), either in biopile or slurry reactors. On the contrary the removal of BFRs in both systems shows differences. Removal after the fungal slurry treatment was rather low compared to the removal obtained in solid-phase system. These results need more research because they are in contradiction with those stated by some researchers that point to the low solubility of these compounds as the limiting factor in its biodegradation. 

Though extensive research has been recently reported in the open literature concerning biodegradation of azo-dyes, there is still a need for additional research. The close link between dye structure and reaction pathways and rates makes it difficult to extrapolate results obtained with one dye to that with others, even belonging to the same class. Dye-specific assessment of process rates and yields is therefore required. Also, the degradation potential of several bacteria or consortia active toward xenobiotics in dye degradation is far from being fully assessed. 

Biodegradable polyester-based nanoparticles have also been studied, especially in the biomedical domain. Like microelectronics, biomedical research follows the rule smaller is better . A typical example of nanoparticles based on the aliphatic polyester engineering by living ROP is provided by the poly(CL-h-GA) copolymers which form stable colloidal dispersions in organic solvents such as toluene and THF without the need of any additional surfactant [27]. The poly(CL-h-GA) particles form a new class of stable non-aqueous dispersions in... 

Environmental Fate. It is not known if 3,3 -dichlorobenzidine, like benzidine, is oxidized by clay minerals or if cations in water ean have the same oxidizing effect. 3,3 -Dichlorobenzidine does not appear to biodegrade easily, but the few studies in this area did not state the type(s) or concentrations of mieroorganisms used in eaeh study. More systematic studies with other organisms may prove useful. A reeent study (Nyman et al. 1997) provides evidence that in the span of a year up to 80% of 3,3 -dichloro-benzidine can degrade to benzidine in anaerobic mixtures of sediment/water. Further research to identify the pathways and produets of deeomposition of 3,3 -dichlorobenzidine in various soils is needed. The toxieologieal profile for benzidine eontains information on the environmental fate of that compound (ATSDR 1995). 

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