Nguyen Van Phuc, Park Suhyun, Oh Junghwan, Wook Kang Hyun
Interdisciplinary Program of Biomedical Mechanical & Electrical Engineering, Pukyong National University, Busan, 48513, South Korea.
Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
J Biophotonics. 2017 Aug;10(8):1053-1061. doi: 10.1002/jbio.201600159. Epub 2016 Sep 12.
Photoacoustic imaging (PAI) is a hybrid imaging modality with high resolution and sensitivity that can be beneficial for cancer staging. Due to insufficient endogenous photoacoustic (PA) contrast, the development of exogenous agents is critical in targeting cancerous tumors. The current study demonstrates the feasibility of marine-oriented material, astaxanthin, as a biocompatible PA contrast agent. Both silicon tubing phantoms and ex vivo bladder tissues are tested at various concentrations (up to 5 mg/ml) of astaxanthin to quantitatively explore variations in PA responses. A Q-switched Nd : YAG laser (λ = 532 nm) in conjunction with a 5 MHz ultrasound transducer is employed to generate and acquire PA signals from the samples. The phantom results presented that the PA signal amplitudes increase linearly with the astaxanthin concentrations (threshold detection = 0.31 mg/ml). The tissue injected with astaxanthin yields up to 16-fold higher PA signals, compared with that with saline. Due to distribution of the injected astaxanthin, PAI can image the margin of astaxanthin boles as well as quantify their volume in 3D reconstruction. Further investigations on selective tumor targeting are required to validate astaxanthin as a potential biocompatible contrast agent for PAI-assisted bladder cancer detection.
光声成像（PAI）是一种具有高分辨率和高灵敏度的混合成像模式，对癌症分期可能有益。由于内源性光声（PA）对比度不足，开发外源性试剂对于靶向癌性肿瘤至关重要。当前研究证明了海洋来源的物质虾青素作为一种生物相容性PA造影剂的可行性。在虾青素的各种浓度（高达5mg/ml）下对硅管模型和离体膀胱组织进行测试，以定量探索PA反应的变化。使用调Q Nd:YAG激光（λ = 532nm）结合5MHz超声换能器从样品中产生并采集PA信号。模型结果表明，PA信号幅度随虾青素浓度呈线性增加（阈值检测 = 0.31mg/ml）。与注射生理盐水相比，注射虾青素的组织产生的PA信号高出多达16倍。由于注入的虾青素的分布，PAI可以在3D重建中对虾青素团块的边缘进行成像并量化其体积。需要对选择性肿瘤靶向进行进一步研究，以验证虾青素作为PAI辅助膀胱癌检测的潜在生物相容性造影剂。
