Zhou Aiguo, Wei Yanchun, Chen Qun, Xing Da
J Biomed Nanotechnol. 2015 Nov;11(11):2003-10. doi: 10.1166/jbn.2015.2150.
Upconversion nanoparticles have shown to be a promising prospect for biological detection and photodynamic therapy (PDT). The focus of this study was to develop an upconversion nanoparticle modified with a targeting peptide and photosensitizer for near-infrared photodynamic therapy. To produce a tumor-targeting nanophotosensitizer with near-infrared excitation, NaYF4:Yb/Er upconversion nanoparticles were first wrapped with O-carboxymethyl chitosan to develop an upconversion rianoplatform and then chemically conjugated with the photosensitizer pyropheophorbide-a (Ppa) and RGD peptide c(RGDyK). The nanoparticle exhibited low dark toxicity and high biocompatibility. When injected into the tail vein of tumor-bearing U87-MG mice, UCNP-Ppa-RGD revealed an enhanced tumor-specific biodistribution and successful therapeutic effect following near-infrared laser irradiation. It possessed a significantly deeper therapeutic depth compared with conventional visible light triggered PDT using Ppa. The results suggest that the nanoplatform has advantages in the spectral application, and the constructed tumor-specific nanoparticle shows high clinical potential to serve not only as a photodynamic imaging reagent but also as a therapeutic agent for the treatment of large or deeply seated tumors.
上转换纳米颗粒已显示出在生物检测和光动力疗法（PDT）方面具有广阔的前景。本研究的重点是开发一种用靶向肽和光敏剂修饰的上转换纳米颗粒，用于近红外光动力疗法。为了制备具有近红外激发的肿瘤靶向纳米光敏剂，首先用O-羧甲基壳聚糖包裹NaYF4:Yb/Er上转换纳米颗粒以构建上转换纳米平台，然后将其与光敏剂焦脱镁叶绿酸-a（Ppa）和RGD肽c(RGDyK)进行化学偶联。该纳米颗粒表现出低暗毒性和高生物相容性。当将UCNP-Ppa-RGD注入荷瘤U87-MG小鼠的尾静脉后，在近红外激光照射下显示出增强的肿瘤特异性生物分布和成功的治疗效果。与使用Ppa的传统可见光触发的光动力疗法相比，它具有明显更深的治疗深度。结果表明，该纳米平台在光谱应用方面具有优势，构建的肿瘤特异性纳米颗粒不仅作为光动力成像试剂，而且作为治疗大肿瘤或深部肿瘤的治疗剂具有很高的临床潜力。
