TY - JOUR
T1 - Effects of plasma treatments on the controlled drug release from poly(ethylene-co-vinyl acetate)
AU - Hagiwara, K.
AU - Hasebe, T.
AU - Hotta, A.
N1 - Funding Information:
This work was supported in part by a Grant-in-Aid for the Global Center of Excellence Program for the “Center for Education and Research of Symbiotic, Safe and Secure System Design” from the Ministry of Education, Culture, Sport, and Technology in Japan (A.H.), a Grant-in-Aid for Scientific Research (B) from the Japan Society for the Promotion of Science (JSPS: “KAKENHI”) (no. 23360294 to A.H.), a Grant-in-Aid for Scientific Research (S) (no. 21226006 to A.H.), and a Grant-in-Aid for Scientific Research for Challenging Exploratory Research (no. 24656395 to A.H.). We are deeply grateful to Prof. Tetsuya Suzuki in Keio University for the CVD equipment.
PY - 2013/2/15
Y1 - 2013/2/15
N2 - Plasma surface treatment was investigated as a surface modification method for a drug-eluting stent (DES) coated with polymers. Currently, the implantation of the DES is the most efficient way to treat a coronary artery disease. DES elutes anti-proliferative drugs that suppress proliferation of smooth muscle cells in the stented segment of the artery. Despite the impressive reduction in restenosis by DES, it still occasionally has a major disadvantage for not preventing restenosis at an implant site due to the relatively vast drug release from the stent surface in the early stages of the drug release. To solve the problem, we studied plasma treatments on the polymer surface because there would not be a substantial risk of damaging the bulk properties of the polymer and the stent by plasma surface treatments. In this study, argon, oxygen, and nitrogen were selected as working gases and poly(ethylene-co-vinyl acetate) (EVA), a hydrophobic biomedical polymer, was selected as a base drug-reservoir material for DES. Structural analyses were carried out by water contact angle measurements, X-ray photon spectroscopy (XPS), and the evaluation of the crosslinking degree of EVA polymer. It was found that the initial burst-release and the cumulative released amount of the drug were both effectively suppressed by controlling the plasma processing time. Furthermore, less effective control of the drug release was obtained by using nitrogen or oxygen plasma as a processing gas instead of argon plasma. According to the evaluation of the crosslinking degree, it was found that argon plasma could most effectively induce the crosslinking in EVA, while nitrogen and oxygen plasmas came in second and third, respectively, which corresponded to the results of the drug release experiments. It was expected that the experimental results of the plasma treatments could provide a new and alternative approach to a controllable and sustainable drug release system.
AB - Plasma surface treatment was investigated as a surface modification method for a drug-eluting stent (DES) coated with polymers. Currently, the implantation of the DES is the most efficient way to treat a coronary artery disease. DES elutes anti-proliferative drugs that suppress proliferation of smooth muscle cells in the stented segment of the artery. Despite the impressive reduction in restenosis by DES, it still occasionally has a major disadvantage for not preventing restenosis at an implant site due to the relatively vast drug release from the stent surface in the early stages of the drug release. To solve the problem, we studied plasma treatments on the polymer surface because there would not be a substantial risk of damaging the bulk properties of the polymer and the stent by plasma surface treatments. In this study, argon, oxygen, and nitrogen were selected as working gases and poly(ethylene-co-vinyl acetate) (EVA), a hydrophobic biomedical polymer, was selected as a base drug-reservoir material for DES. Structural analyses were carried out by water contact angle measurements, X-ray photon spectroscopy (XPS), and the evaluation of the crosslinking degree of EVA polymer. It was found that the initial burst-release and the cumulative released amount of the drug were both effectively suppressed by controlling the plasma processing time. Furthermore, less effective control of the drug release was obtained by using nitrogen or oxygen plasma as a processing gas instead of argon plasma. According to the evaluation of the crosslinking degree, it was found that argon plasma could most effectively induce the crosslinking in EVA, while nitrogen and oxygen plasmas came in second and third, respectively, which corresponded to the results of the drug release experiments. It was expected that the experimental results of the plasma treatments could provide a new and alternative approach to a controllable and sustainable drug release system.
KW - Drug release
KW - Plasma treatment
KW - Polymer
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U2 - 10.1016/j.surfcoat.2012.11.064
DO - 10.1016/j.surfcoat.2012.11.064
M3 - Article
AN - SCOPUS:84872965013
SN - 0257-8972
VL - 216
SP - 318
EP - 323
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
ER -