| Shaun Bainbridge of CSMA discusses the role of surface analysis in the development of drug delivery systems for cardiovascular stents
The topic of drug eluting stents (DESs), and their importance to the medical world, is frequently debated at present. What was once hailed as a medical breakthrough set to revolutionise the treatment of blocked arteries is now under criticism (by some parties at least) for failing to achieve what arguably was promised by earlier indicators. To understand how this situation has arisen, it is crucial to have some knowledge of the background to drug delivering stent coatings – a background which has been heavily influenced by surface analysis techniques.
IN THE BEGINNING
Stents (metal mesh tubes inserted post angioplasty to treat blocked/restricted coronary arteries) have been in common usage for around 10 years. Initially, the metal structures featured no special pharmaceutical coatings or treatments and simply performed a ‘scaffold’ function to prevent blockage. However, it soon became apparent that reclosure (restenosis), due to the host’s reaction to the foreign metal insert, was an issue – the situation occurring in around 30 per cent of cases. It was decided that an appropriate solution to this problem would be to treat stents with specially developed coatings that would facilitate drug delivery over a specific period in order to prevent restenosis from occurring – a simple solution in theory, a difficult one in practice. |
