Elucidation of generation mechanism and propagation behavior of femtosecond laser-induced underwater shock wave, and development of microcapsules including gas bubbles for regenerative medicine

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01252
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 19010:Fluid engineering-related
• Research Institution: Kyushu Institute of Technology
• Principal Investigator: Tamagawa Masaaki 九州工業大学, 大学院生命体工学研究科, 教授 (80227264)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: マイクロ衝撃波 / 再生医工学 / フェムト秒レーザ / 衝撃波生成機序 / 気泡内包カプセル

Outline of Final Research Achievements

In this study, as one application of shock waves to regenerative medicine, we propose a system that applies micro-shock waves from the outside to tissue structures assembled from microcapsules containing gas bubbles and cells. For this application, to elucidate the generation and propagation mechanism of femtosecond pulsed laser-induced shock waves, there are three objectives: (1) to generate micro-shock waves by focusing a laser in water, (2) to find out the optimal conditions for rupturing capsule, and (3) to investigate the propagation and attenuation mechanisms of shock waves in a bubble-encapsulated capsule. As results, (1) two-dimensionally the shock wave front and its propagation after the micro-shock wave was captured by using high-speed images, (2) the pseudo-thickness of the micro-shock wave in water and silicone oil can be suggested, and (3) it is necessary to take into account the law of conservation of energy and the effects of air bubbles for CFD analysis.

Free Research Field

流体工学，生体医工学

Academic Significance and Societal Importance of the Research Achievements

本研究課題の学術的独自性として，フェムト秒レーザー誘起水中マイクロ衝撃波生成や伝播などの高速現象を顕微鏡下で可視化し，理論的足がかりをつけて，医療に応用することを目的としており，時間の長いナノ秒レーザー誘起衝撃波のものとは予測の異なる結果が期待できることである．一方，学術的創造性としては，カプセル内部細胞への“力学的刺激”と“カプセル破壊”の切り替えができる医用工学技術の創造によって，再生医療工学として国内外でも報告されていない新しい方法，すなわち細胞の増殖刺激とカプセル破壊を同時に行うことが可能となることである．