Materials Science and Engineering Program, University of California San Diego, La Jolla, California, 92093, United States.
Department of Nanoengineering, University of California San Diego, La Jolla, California, 92093, United States.
Nanotheranostics. 2022 Jan 1;6(1):79-90. doi: 10.7150/ntno.63634. eCollection 2022.
Gold nanorods (GNRs) have attracted great interest for photo-mediated biomedicines due to their tunable and high optical absorption, high photothermal conversion efficiency and facile surface modifiability. GNRs that have efficient absorption in second near-infrared (NIR-II) window hold further promise in bio-applications due to low background signal from tissue and deep tissue penetration. However, bare GNRs readily undergo shape deformation (termed as 'melting effect') during the laser illumination losing their unique localized surface plasmon resonance (LSPR) properties, which subsequently leads to PA signal attenuation and decreased photothermal efficiency. Polydopamine (PDA) is a robust synthetic melanin that has broad absorption and high photothermal conversion. Herein, we coated GNRs with PDA to prepare photothermally robust GNR@PDA hybrids for enhanced photo-mediated theranostic agents. Ultrasmall GNRs (SGNRs) and conventional large GNRs (LGNRs) that possess similar LSPR characteristics as well as GNR@PDA hybrids were compared side-by-side in terms of the size-dependent photoacoustic (PA) imaging, photothermal therapy (PTT), and structural stability. experiments further demonstrated that SGNR@PDA showed 95% ablation of SKOV3 ovarian cancer cells, which is significantly higher than that of LGNRs (66%) and SGNRs (74%). Collectively, our PDA coating strategy represents a rational design for enhanced PA imaging and efficient PTT via a nanoparticle, i.e., nanotheranostics.
金纳米棒（GNRs）因其可调谐的高光吸收、高光热转换效率和易于表面修饰而在光介导的生物医学中引起了极大的兴趣。由于组织的背景信号低且能深层穿透组织，在近红外二区（NIR-II）窗口中具有高效吸收的 GNRs 在生物应用中具有更大的潜力。然而，裸 GNRs 在激光照射下容易发生形状变形（称为“熔化效应”），从而失去其独特的局域表面等离子体共振（LSPR）特性，这会导致 PA 信号衰减和光热效率降低。聚多巴胺（PDA）是一种强大的合成黑色素，具有广泛的吸收和高光热转换效率。在此，我们用 PDA 包裹 GNRs 来制备光热稳定的 GNR@PDA 杂化材料，以增强光介导的治疗剂。在尺寸依赖性光声（PA）成像、光热治疗（PTT）和结构稳定性方面，我们对具有相似 LSPR 特性的超小 GNRs（SGNRs）和常规大 GNRs（LGNRs）以及 GNR@PDA 杂化物进行了并排比较。实验进一步证明，SGNR@PDA 能实现 SKOV3 卵巢癌细胞 95%的消融，明显高于 LGNRs（66%）和 SGNRs（74%）。总的来说，我们的 PDA 涂层策略代表了一种通过纳米颗粒增强 PA 成像和高效 PTT 的合理设计，即纳米治疗学。
