Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Block EA #03-12, 9 Engineering Drive 1, 117576, Singapore.
Chem Soc Rev. 2015 Mar 21;44(6):1449-78. doi: 10.1039/c4cs00158c.
Remote activation of photoactivable therapeutic compounds by light provides a high spatial and temporal control for activating the therapeutic agent. However, photoactivable compounds are mostly responsive towards ultraviolet (UV) or visible light radiation that has poor tissue penetration depth besides being unsafe to the body in the case of UV light. Nanoparticles with energy upconversion hold potential in overcoming this limit by using safe and deeply penetrating near-infrared (NIR) light. These upconversion nanoparticles (UCNs) act as versatile nanotransducers as they convert NIR light to light of shorter wavelengths that can be tuned to the NIR, visible or UV colors to suit different activation wavelengths. Their highly unusual optical properties to fluoresce with near-zero photobleaching, photoblinking and background autofluorescence are unique and an added benefit when used simultaneously as optional imaging agents. This article reviews recent advancements in the use of UCNs for photoactivation of therapeutic agents. Specifically, we discuss the use of these UCNs for activation of light-sensitive/photocaged molecules or photosensitizers for photocontrolled-delivery and photodynamic therapy.
远程激活光激活治疗化合物通过光为激活治疗剂提供了高空间和时间控制。然而，光激活化合物大多对紫外线 (UV) 或可见光辐射有反应，除了紫外线对身体不安全之外，这种辐射的组织穿透深度也很差。具有能量上转换的纳米粒子具有利用安全且深穿透近红外 (NIR) 光克服这一限制的潜力。这些上转换纳米粒子 (UCNs) 作为多功能纳米换能器发挥作用，因为它们将 NIR 光转换为较短波长的光，这些光可以调谐到 NIR、可见光或 UV 颜色，以适应不同的激活波长。当它们同时用作可选成像剂时，它们具有独特的、额外的益处，即近零光漂白、光闪烁和背景自发荧光的高度异常光学特性。本文综述了 UCN 在光激活治疗剂方面的最新进展。具体来说，我们讨论了这些 UCN 在激活光敏感/光笼分子或光增敏剂以进行光控递药和光动力治疗方面的用途。
