Drug Eluting Stent Key Words: drug eluting stent, polymer,
rapamycin,
paclitaxel Abstract: Drug eluting stent(DES),coated
with drug dissolved in the polymer which serves as matrix and release the drug in a relative low speed and last a long term after the stent is implanted into the patient’s coronary vessel. Compared with the bare metal stent(BMS),it could reduce restenosis more effectively by reducing the occurrence of MACE(main adverse cardiac event),TVR(target vessel revascularization),TLR(target lesion revascularization),etc. The drug used now mainly include two kinds:
Rapamycin and
Paclitaxel. The former is used by CypherTM stent manufactured by Cordis(Johnson and Johnson).The CypherTM stent uses PEVA/PMBA as its carrier.And the polymer PEVA and PMBA have been long used and they have been showed well safty. While the later is used by Taxus ExpressTM manufactured by Boston Scientific. Poly(styrene-b-isobutylene-b-styrene) is the polymer for its drug eluting stent’s matrix. Chinese drug eluting stent called Firebird is also used with rapamycin as its drug. Rapamycin is a sort of immunosuppressant and antifungal antibiotic ,first was separated and purified from link strain. It also shows anti-inflammation,which anti the transfer of the inflame factors.Paclitaxel is anti-tumor chemical substance purified form plants known as Japanese yew branchlet and leaf . It enhances the assembling of microtubule and prevents the disassembling of it, thus hauls the mitosis of human cells .Thus would reduce the restenosis caused by proliferation of cells in the cororary injured by the implanting of DES or the stent itself.