Degradation long-term study

Marois, Y., Zhang, Z., Vert, M., Deng, X., Lenz, R. and Guidoin, R., 1999, Mechanism and rate of degradation of polyhydroxyoctanoate films in aqueous media a long term study, J. Biomed. Mater. Res. 49 216-224... 

To overcome these medium- to long term substrate degradation issues, the surface of the structured material has to be properly prepared and protected during the phase of assembly and catalyst coating. This feature is so important that, as mentioned before, almost no relevant and detailed long-term studies have been reported yet on the corrosion effects on stainless-steel microstructured platelets. 

Figure 8.14 Long-term study for degradation of 2,2 -dichlorobiphenyl (DCB) under pressure-...

Considering the high hydrophobicity of the palmitoyl side chain and the rigidity of the polymer backbone, we assumed that poly(N-palmitoylhydroxyproline ester) would degrade somewhat more slowly than poly (lactic acid) or polycaprolactone. In order to confirm this hypothesis, a series of long-term stability and degradation studies have been performed over the last 2 years at MIT (22). 

Based on these studies, it is obvious that poly(N-acylhydroxy-proline esters) are very slowly degrading polymers. These materials may therefore be useful for long-term applications, such as implantable, multiyear contraceptive formulations. For such applications the degradation rates of poly (lactic acid)/poly (glycolic acid) devices would probably be too rapid. 

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