Development of medical materials for soft tissue reconstruction using new highly elastic and biodegradable polymers

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K23603
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0403:Biomedical engineering and related fields
• Research Institution: Nagoya University
• Principal Investigator: MURAYAMA Atsuhiko 名古屋大学, 医学部附属病院, 病院助教 (90844457)
• Project Period (FY): 2019-08-30 – 2023-03-31
• Keywords: 生分解性プラスチック / PHA / 伸縮性 / 柔軟性 / 生体適合性

Outline of Final Research Achievements

Fibrous samples, utilizing a novel PHA sterilized by EO gas, were implanted in the dorsal subcutaneous tissue of rats for a specific duration before being removed. The study encompassed the following observations: 1) macroscopic and microscopic examination of the sample structure, 2) histological evaluation of inflammation in the surrounding implanted tissue, and 3) confirmation of the residual tensile strength. The findings were as follows: 1) At one year post-implantation, all samples exhibited partial degradation without any evident signs of infection. Scanning electron microscopy revealed the progression of fine cracks and crater-like changes, indicating slow bioabsorbability. 2) The results suggest that the degree of inflammation is relatively low compared to existing absorbable medical materials. 3) The in vivo half-life of tensile strength was approximately 26 weeks, indicating the maintenance of strength over the medium to long term.

Free Research Field

人間医工学及びその関連分野

Academic Significance and Societal Importance of the Research Achievements

現存する医療用吸収性材料は、主にポリ乳酸やポリグリコール酸から成るが柔軟性や生体適合性という点で問題となることがある。人工神経の足場は柔軟性に乏しく関節近傍での適応がなく、吸収過程で炎症を引き起こすことが報告されている。人工靭帯は伸展性や伸展したあとの復元性に乏しく、靭帯の生態学的な機能を正しく補完していない。新たな生分解性プラスチックであるP(3HB-co-4HB)を用いた繊維性サンプルは、生体にとって安全であり、ゆっくりと分解され、高い伸縮性や柔軟性を持っている。これらは現存する生体吸収性医療材料にはない特徴であり、アンメットニーズに応えるポテンシャルを秘めており新規性がある。