Enhanced degradability of bioabsorbable small-caliber artificial vessels to promote autologous vascular regeneration

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20938
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0905:Surgery of the organs maintaining homeostasis and related fields
• Research Institution: Asahikawa Medical College
• Principal Investigator: Masahiro Tsutsui 旭川医科大学, 医学部, 助教 (00910267)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: 生体吸収性人工血管 / ナノファイバー

Outline of Final Research Achievements

Although we could not reach the point of creating polycaprolactone (PCL) grafts with improved degradability, it is necessary to improve the patency of the artificial vessels in order to evaluate their degradability. In this study, we attempted to improve patency by coating the PCL grafts with polyvinyl alcohol (PVA). In vitro, PVA inhibited platelet adsorption, but caused thrombus formation under whole blood conditions. Here, we focused on the hydrophilic nature of PVA, and suggested the possibility of improving the coating function by exposing the hydrophilic coating to whole blood with the hydrophilic coating activated in advance with ultrapure water. In addition, for the purpose of long-term evaluation of degradability, a shift from the rat model to the rabbit model was examined. With the rabbit model, it was possible to evaluate relatively long-term patency and establish a long-term degradability evaluation model.

Free Research Field

生体吸収性人工血管

Academic Significance and Societal Importance of the Research Achievements

心臓外科領域において、即時利用可能な小口径人工血管の開発は必要不可欠である一方で、現状、一般に臨床応用されている小口径人工血管は存在しない。本研究はその開発において、特に問題となりやすい人工血管のコーティングに関する知見に関して、一定の知見を得られたと考える。親水性コーティングに関しては、一度超純水に晒すことで水の膜を形成し、親水コーティングの性能を発揮する可能性を示唆したが、今後の研究で親水性コーティングのさらなる改良が必要と思われる。
また、分解性を長期的に評価する動物モデルを作成したことで、今後作成する新たなナノファイバーグラフトを長期に評価し、分解性を検証、改良することが可能と考える。