KINETICS OF DEGRADATION OF ANTIPROLIFERATIVE POLYMER COATING OF STENTS IN VITRO

Lyubchenko Olesya Dmitrievna, Postgraduate student, Penza State University (40 Krasnaya street, Penza, Russia). filology@inbox.ru
Kruchinina Anastasya Dmitrievna, Postgraduate student, assistant, sub-department of general biology and biochemistry, Penza State University (40 Krasnaya street, Penza, Russia), a.d.kruchinina@mail.ru
Shatrov Alexey Nikolaevich, Chief executive officer “NanoMed, Ltd” (1 Tsentralnaya street, Penza, Russia), nanomed_penza@mail.ru

577.033

Background. The study is aimed at investigation of the kinetics of degradation of the polymer coating of sirolimus-eluting stents with thickness of 20 microns on the basis polylactid-co-glicolid with copolymers ratio 50:50.
Materials and methods. When developing of the antiproliferative stent coatings, polylactid-co-glycolid was used as a matrix for the drug and Sirolimus as an active substance. When modeling the process of coating degradation, sirolimus concentration in the solution was determined spectrophotometrically every 48 hours. Evaluation of the degradation rate of the polymer was carried out through a decrease of characteristic viscosity of the material and a content of lactate in the buffer solution weekly.
Results. The experimental results of determination of the lactate concentration in the buffer solution and the characteristic viscosity of the polymer coating solutions are correlated in the dynamics of degradation. It has been discovered that the breakdown rate of the polymer coating corresponds to the required release rate of sirolimus to reduce the risk of restenosis.
Conclusions. Consequently, the results testify to a sufficient level of local drug release to prevent restenosis in the early postimplantation period.

degradation, sirolimus, stent, antiproliferative coating, polylactidco-glycolid, lactate, intrinsic viscosity.

1. Oganov R. G., Maslennikova G. Ya. Kardiovaskulyarnaya terapiya i profilaktika [Cardiovascular therapy and prophylaxis]. 2002, vol. 3, pp. 4–8.
2. Erbel R., Haude M., Hopp H. W., Franzen D., Rupprecht H. J., Heublein B., Fischer K., P. de Jaegere, Serruys P., Rutsch W., Probst P. N. Engl. J. Med. 1998, vol. 339, no. 23, pp. 1672–1678.
3. Bokeriya L. A., Alekyan B. G. Rukovodstvo po rentgenendovaskulyarnoy khirurgii serdtsa i sosudov [Guide on X-ray endovascular surgery of heart and vessels]. 2013, vol. 3, 598 p.
4. Katz G., Harchandani B., Shah B. Curr Atheroscler Rep. 2015, vol. 17, no. 3, pp. 485–488.
5. Claessen B. E., Henriques J. P., Dangas G. D. Curr Pharm Des. 2010, vol. 16, no. 36, pp. 4012–4024.
6. Sevast'yanov V. I., Kirpichnikov M. P. Biosovmestimye materialy [Biocompatible materials]. Moscow: Med. inform. agentstvo, 2011, 544 p.
7. GOST R ISO 10993–2011. Otsenka biologicheskogo deystviya meditsinskikh izdeliy [Standard GOST R ISO 10993–2011. Estimation of biological activity of medical products]. Moscow: Standartinform, 2013, 14 p.
8. GOST R ISO 13781–2011. Smoly i otformovannye elementy na osnove poli (L-laktida) dlya khirurgicheskikh implantatov. Issledovanie degradatsii metodom in vitro [Standard GOST R ISO 13781–2011. Resins and shaped elements poly-L-lactide for surgical implants.Degradation research in vitro]. Moscow: Standartinform, 2011,12p.
9. Xu Q. A., Madden T. L. John Wiley & Sons. 2011, 576 p.
10. GOST 18249–72. Plastmassy. Metod opredeleniya vyazkosti razbavlennykh rastvorov polimerov [Standard GOST 18249–72. Plastics. Method of viscosity determination for solution-diluted polymers]. Moscow: Izd-vo standartov, 2000, 7 p.
11. Tits N. U. Entsiklopediya klinicheskikh laboratornykh testov [Encyclopedia of clinical laboratory tests]. Moscow: Labinform, 1997, 960 p.
12. Lakin G. F. Biometriya [Biometrics]. Moscow: Vyssh. shk., 1990, 350 p.
13. Wei Z., Liu L., Zhang M., Yang F., Qi M. Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2008, vol. 25, no. 1, pp. 122–126.