Photoacoustic (PA) theranostics is a new emerging field that uniquely combines diagnosis and treatment in one modality. However, its current status is compromised by the indispensable dependence on nonreversible phase-change nanoprobes that provides one-time-only action. Here, we demonstrate a picosecond-laser-pumped ultrafast PA cavitation technique for highly efficient shockwave theranostics, guaranteeing sustained PA cavitation by using non-phase-change nanoprobes. Theoretical simulations validate that, when compressing the excitation laser pulse width to hundred-picosecond, the thermal confinement effects of a conventional nanoprobe will induce transient heating of the extremely thin surrounding liquid layer of the nanoprobes beyond its cavitation point in a localized area at nanoscale, resulting in intense cavitation and PA shockwaves by the environment rather than the nanoprobes. Both cellular and mouse model experiments have demonstrated the highly effective anti-tumor effects. This method provides a sustainable, reproducible, and highly effective strategy for PA theranostics, prefiguring great potential for the clinical applications.

中文翻译：

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皮秒激光泵浦的超快光声空化可实现高效、长期的冲击波治疗诊断

光声（PA）治疗诊断学是一个新兴领域，将诊断和治疗独特地结合在一种模式中。然而，其目前的地位受到了对不可逆相变纳米探针不可逆的依赖性的影响，这种纳米探针只能提供一次性作用。在这里，我们展示了一种用于高效冲击波治疗诊断的皮秒激光泵浦超快 PA 空化技术，通过使用非相变纳米探针保证持续的 PA 空化。理论模拟验证，当将激发激光脉冲宽度压缩到百皮秒时，传统纳米探针的热约束效应将导致纳米探针周围极薄液体层瞬态加热，超出纳米尺度局部区域的空化点，导致强烈的空化和 PA 冲击波是由环境而不是纳米探针产生的。细胞和小鼠模型实验均证明了其高效的抗肿瘤作用。该方法为 PA 治疗诊断提供了一种可持续、可重复且高效的策略，预示着临床应用的巨大潜力。