내피 세포 캡처 및 유지에 대한 강자성 베어 메탈 스텐트
Summary
우리의 목표는 설계, 제조 및 내피 세포 캡처를위한 강자성 스텐트를 테스트했다. 열 스텐트 파괴에 대해 시험하고, 10 이상이 유지 자성 스텐트에 대해 시험 하였다. 마지막으로, 10 스텐트는 시험관 시험하고 8 개의 스텐트는 세포 캡처 및 보존을 보여 4 돼지에 이식했다.
Abstract
심혈관 스텐트에 내피 세포가 급속 스텐트 혈전증을 감소시키고 출혈 위험을 줄일 수있는 항 혈소판 요법을 피하기 위해 필요하다. 초 상자성 산화철 나노 입자 (SPION)로 표지 내피 세포 생장 (EOC)를 캡쳐하고 유지하기 위해 자력을 이용의 가능성은 이미 밝혀졌다. 그러나이 기술은 빠른에 내피 증명 시험관 내 및 생체 내 시험 하였다 자기 및 생체 물질로부터 기계적 작용 성 스텐트의 개발이 필요하다. 우리는 컴퓨터 이용 설계 (CAD)를 이용하여 2,205 듀플렉스 스테인레스 약하게 강자성 스텐트를 개발하고 설계는 또한 유한 요소 해석 (FEA)을 사용하여 정제 하였다. 스텐트의 최종 설계는 기계적 권축과 팽창시에 재료의 파단 한계 이하 주 변형률을 나타냈다. 백 스텐트를 제작하고, 그 중 일부는 기계적 시험, RET에 사용 된ained 자기장 측정 시험관 세포 캡처 연구 및 생체 내 주입 연구. 텐 스텐트은 실패없이 사이클을 압착 및 확장 입었 있는지 확인하기 위해 배포를 테스트 하였다. 다른 스텐트 (10)는 강한 네오디뮴 자석을 이용하고, 그들의 자화 유지 자기장을 측정 하였다. 스텐트는 유지 자기가 우리의 시험관 연구에서 SPION 표지 EOC를 캡처하기에 충분한 것으로 나타났다. SPION 표지 EOC 캡처 및 보유 1 자화 스텐트 4 돼지의 각 1 비 자화 제어 스텐트를 주입하여 큰 동물 모델에서 확인되었다. 스텐트 동맥 7 일 이후 외식 및 조직 학적으로 분석 하였다. 본 연구에서 개발 된 약하게 자기 스텐트 유치와 빠른 치유를 촉진 할 수 SPION 표지 내피 세포를 보유 할 수 있었다.
Introduction
Patients implanted with vascular stents manufactured from thrombogenic materials like stainless steel, cobalt chromium, and platinum chromium – both bare metal stents (BMS) and drug eluting stents (DES) – need anti-platelet therapy to prevent thrombus formation. BMS heal rapidly, but are subject to late stage restenosis due to incomplete healing. DES require long term anti-platelet therapy due to delayed healing. Anti-platelet therapy administered to avoid thrombosis as a result of incomplete or delayed healing leads to increased bleeding risk and may not be suitable for certain patients1,2. An ideal stent will heal completely and quickly thus avoiding long-term anti-platelet therapy and late stage restenosis. This complete healing can only be achieved if the stent is rapidly coated with a monolayer of endothelial cells after implantation. Coating the stents with biocompatible materials such as gold or other biopolymers has been shown to improve thrombo-resistance, but none of these techniques achieved ideal blood compatibility as may be possible by coating with endothelial cells3,4.
A stent can be coated with endothelial cells post implantation by attracting circulating progenitor cells. This self-seeding technique can be achieved by utilizing ligands and antibodies. But this technique is limited by the low number of circulating endothelial progenitor cells. A promising strategy is to deliver cells directly to the stent immediately following implantation during a short period of blood flow occlusion3,5. This strategy requires a technique for rapidly capturing cells and retaining them on the stent even after restoring blood flow. We have developed a technique in which a magnetic stent is used to attract and retain magnetically-labeled endothelial cells delivered post implantation. To achieve this, a functional BMS with sufficient magnetic properties to capture and retain magnetically-labeled endothelial cells is required6.
In this paper, we discuss the methods for designing, manufacturing, and testing a 2205 stainless steel stent. The stents were designed using CAD and FEA. The manufactured stents were magnetized using a neodymium magnet and the retained magnetic field was measured using a magneto-resistance microsensor probe. We then tested the stents for magnetically-labeled cell capture in a culture dish during our in-vitro experiments. Finally, the stents were tested in-vivo by implanting magnetic and non-magnetic stents in 4 pigs and histologically analyzing the stented arteries.
Protocol
Representative Results
Discussion
우리는 베어 메탈 스텐트의 기능을 할 수 있으며 SPION 표지 내피 세포를 유치 할 수있는 자기 스텐트를 개발했다. 자기 스텐트와 관련된 이전 연구에서 연구팀은 (는) 강자성 스텐트 5,10-14의 불가능에 자성 재료로 만든 니켈 코팅 된 상업 스텐트 및 코일 또는 메쉬를 사용했습니다. 다른 그룹은 나노 입자로드 내피 세포 3을 대상으로 시판 304 등급의 스테인레스 스틸 스텐트의 상자?…
Divulgazioni
The authors have nothing to disclose.
Acknowledgements
The authors thank Tyra Witt, Cheri Mueske, Brant Newman and Dr. Peter J. Psaltis, MBBS, PhD for their valuable contributions. This study was financially supported by European Regional Development Fund – FNUSA-ICRC (No. CZ.1.05/1.100/02.0123), American Heart Association Scientist Development Grant (AHA #06-35185N), National Institutes of Health (T32HL007111) and The Grainger Innovation Fund – Grainger Foundation.
Materials
| 2205 Stainless steel | Carpenter Technology Corporation | N/A | Round bar stock material |
| Abaqus | Dassault systems | N/A | Software |
| Atropine | Prescription drug. | ||
| Clopidogrel | Commercial name: Plavix. Prescription drug. | ||
| CM-DiI | Life Technologies | V-22888 | Molecular Probes, Eugene, OR |
| Endothelial growth medium-2 | Lonza | CC-3162 | |
| Hand Held Crimping tool | Blockwise engineering | M1-RMC | |
| Hydrochloric acid (HCl) | Sigma Aldrich | MFCD00011324 | CAUTION: wear proptective equipment and handle under fume hood |
| Isoflurane anesthesia | Piramal Critical Care, Inc. | ||
| Isopropyl alcohol | Sigma Aldrich | MFCD00011674 | |
| NdFeB magnet 2" Dia x 1" thick | Amazing magnets | D1000P | Axially magnetized disc magnet with poles on flat faces |
| Over-The-Wire trifold balloon | N/A | N/A | Any commercially available OTW trifold balloon can be used |
| Phosphate buffered saline | Life Technologies | 10010-023 | Commonly known as PBS |
| Sodium Bicarbonate (NaHCO3) | Sigma Aldrich | MFCD00003528 | |
| Sodium pentobarbital | Zoetis | Commercial Name: Sleepaway (26%), FatalPlus, Beuthanasi. Controlled substance to be ordered only by licensed veternarian | |
| SolidWorks | Dassault systems | N/A | Software |
| SpinTJ-020 micro sensor | MicroMagneitcs Sensible Solutions | N/A | Long probe STJ-020 microsensor |
| SPION | Mayo Clinic | N/A | Nanoparticles synthesized internally (Ref: Lee, S. J. et al. Nanoparticles of magnetic ferric oxides encapsulated with poly(D,L latide-co-glycolide) and their applications to magnetic resonance imaging contrast agent. J Magn Magn Mater 272, 2432-2433, doi:DOI 10.1016/j.jmmm.2003.12.416 (2004)) |
| Telazol | Zoetis | Controlled substance to be ordered only by licensed veternarian | |
| Trypsin EDTA | Life Technologies | 25200-056 | Gibco, Grand Island, NY |
| Xylazine | Bayer Animal Health | Commercial name: Rompun. Controlled sunstance to be ordered only by a licensed veternarian |
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