Multifunctional gold nanorod composite for NIR imaging and photodynamic therapy treatment of tumor

The preparation of an effective functional nanomaterial that combines near-infrared imaging and photodynamic therapy functions remains a highly challenging task. The unique tunable optical properties of gold nanorods in the near-infrared region compensate for the limitations of traditional fluorescent dyes and other metal nanoparticles in biological imaging applications. Gold nanorods play a crucial role in biological tissue imaging, early cancer diagnosis and therapy. In this paper, we got gold nanorods in different aspect ratio by adjusting the content of AgNO3 in the growth solution. Subsequently, we developed a novel multi-functional delivery system (5-ALA-loaded GNRs@SiO2@PHIS) using GNRs as cores. The nanocomposite was loaded with a photosensitizer called 5-Aminolevulinic acid (ALA) and conjugated with a pH-sensitive polymer called poly-histidine (PHIS). The PHIS can induce pH-triggered drug release and facilitate endo/lysosome escape, thereby enhancing drug efficacy. The current study on in vitro experiments indicated that the multifunctional gold nanorod composite exhibit strong light scattering in the near-infrared region and effectively induced cancer cell through photodynamic therapy treatment. Overall, this study presents an innovative strategy for the development of versatile photodynamic therapy for cancer theranostics.