Related Experiment Video
Updated: Oct 13, 2025
Fluorescence-quenching of a Liposomal-encapsulated Near-infrared Fluorophore as a Tool for In Vivo Optical Imaging
Published on: January 5, 2015
A lipid droplet specific fluorescent probe for image-guided photodynamic therapy under hypoxia
Weihua Zhuang1,2, Ping Tan3, Shufen Li1
1Laboratory of Heart Valve Disease, West China Hospital, Sichuan University, 37 Guoxue Road, Chengdu 610041, P. R. China. hmaochen@vip.sina.com.
Abstract:
Photodynamic therapy (PDT) is a potential strategy for many superficial, esophageal, intestinal, and bronchial cancer treatments, but its therapeutic effect is limited by a lack of specificity and the hypoxic tumor environment. It is necessary to develop novel photosensitizers (Ps) with organelles targeting and the ability to generate cytotoxic species under light irradiation without the presence of oxygen. Herein, we designed and synthesized a biocompatible fluorescent Ps CPNBD for lipid droplets (LDs) fluorescence (FL) image-guided PDT. CPNBD showed FL quenching in water but FL was significantly turned on by oil with a remarkable FL enhancement compared to that in aqueous solution. Due to its strong lipophilicity (Clog P of 7.96), CPNBD could specifically stain the LDs of human clear cell renal cell carcinoma (ccRCC) tumor cells and tissues with good photostability. Meanwhile, CPNBD could efficiently generate cytotoxic reactive oxygen species under low-power white-light irradiation, which could efficiently damage DNA via a PDT process with great tumor suppression ability in vitro and in vivo. Thus, this work provides a novel strategy for designing LD-targeting Ps with efficient image-guided PDT under the tumor hypoxic environment.
Insights
Researchers developed a novel photosensitizer (CPNBD) that targets lipid droplets for fluorescence-guided photodynamic therapy (PDT). This approach overcomes tumor hypoxia and enhances cancer treatment efficacy both in vitro and in vivo.
Area of Science:
- Biochemistry
- Nanotechnology
- Oncology
Background:
- Photodynamic therapy (PDT) shows promise for various cancers but faces limitations due to poor specificity and hypoxic tumor microenvironments.
- Developing novel photosensitizers (Ps) that target specific organelles and generate cytotoxic species independent of oxygen is crucial for improving PDT efficacy.
Purpose of the Study:
- To design and synthesize a biocompatible, lipid droplet-targeting fluorescent photosensitizer (CPNBD) for image-guided photodynamic therapy.
- To evaluate CPNBD's ability to generate reactive oxygen species under light irradiation and its efficacy in cancer treatment under hypoxic conditions.
Main Methods:
- Synthesis of a novel fluorescent photosensitizer, CPNBD, with high lipophilicity (ClogP = 7.96).
- Evaluation of CPNBD's fluorescence properties in aqueous and oil environments, and its photostability.
- Assessment of CPNBD's ability to specifically stain lipid droplets in clear cell renal cell carcinoma (ccRCC) cells and tissues.
- Investigation of CPNBD's capacity to generate reactive oxygen species (ROS) under white-light irradiation and its efficacy in vitro and in vivo cancer models.
Main Results:
- CPNBD exhibits fluorescence quenching in water but significant fluorescence enhancement in oil, enabling effective lipid droplet staining.
- CPNBD specifically targets and stains lipid droplets in ccRCC cells and tissues with good photostability.
- CPNBD efficiently generates cytotoxic ROS under low-power white-light irradiation, leading to DNA damage and significant tumor suppression in vitro and in vivo.
- The developed photosensitizer functions effectively even in hypoxic tumor environments.
Conclusions:
- CPNBD is a novel, biocompatible photosensitizer capable of targeting lipid droplets for fluorescence-guided photodynamic therapy.
- This approach offers a promising strategy for overcoming the limitations of tumor hypoxia and enhancing PDT efficacy.
- CPNBD demonstrates significant potential for image-guided cancer treatment with high tumor suppression ability.
