RECENT ADVANCEMENT IN DEVELOPMENT OF DRUG ELUTING STENTS DELIVERY SYSTEM

MUKUND LATA BHARTI

ABSTRACT
Cardiovascular diseases are one of the major causes of death in industrially developed countries.  In particular occlusive pathologies of coronary and peripheral arteries are the third cause of  death in these countries. The recent introduction of drug eluting stents (DES) technology  contributes a major advancement in the treatment of obstructive coronary – artery  diseases.  A  DES is a peripheral or coronary stent ( scaffold ) which slowly elutes a drug locally, design to  limit the growth of neointimal scar tissue;  thus reducing the likelihood of stent restenosis.  In  DES  designing  the   Stent  platform  (metallic platform),  Coating  (a  drug  carrier  vehicle  which holds and elutes the drug in a controlled manner), Active therapeutic agent (reduces  neointimal growth) are three major parts are used; for stent platform different type of  metallic  can be used like stainless steel, nitinol, cobalt, chromium, platinum, gold, magnesium  alloy etc,  and polymers which are generally used in DES are  may be Biodegradable polymers (like  poly  lacticacid (PLA), poly glycolic acid (PLGA), poly caprolactone (PCL) etc. or Non  biodegradable polymers (like polybutylmethacrylate (PBMA), polymethyl-methacrylate  (PMMA), phosphorylcholine, polyethyleneterphthalate (PET) and the drug incorporated in the  stent is basically Immunosuppressive and Antiproliferative drugs like Sirolimus, Everolimus, Zotarolimus, Paclitaxel etc. to inhibit neointimal growth which would cause restenosis. The success of DES in a long term clinical outcome basically depends upon Stent configuration, Strut Thickness, Stent coating, and Drug elution. Therefore, the introduction of DES in percutaneous coronary intervention (PCI) is a major innovative advancement in interventional cardiology. DES dramatically reduces the ISR rate in all subgroups of patients. Continuing improvement in drug delivery stent technologies and gradual reduction in cost makes DES an effective mainstay of therapy for CAD.
Key  Words:  Stent,  Coating,  Restenosis,  Drug loading,  Coronary  artery  disease  (CAD).

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