• The role of metal nanoparticles in photodynamic cancer therapy
  • Roxan Jafari,1 Mahnaz Hadizadeh,2,*
    1. The Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
    2. Department of Biotechnology, Iranian Research Organization for Science and Technology (IROST), P.O. Box 3353-5111, Tehran 3313193685, Iran, P. O. Box 3353-5111., Iran.


  • Introduction: Photodynamic therapy (PDT) is a non-invasive and selective form of light therapy that applies a photosensitizer, molecular oxygen, and visible light to destroy malignant cells. Recently, metal-based nanoparticles have attracted attention as photosensitizers, nanocarriers, and up-conversion tools. Metal nanocarriers play an important role in enhancing photodynamic therapy (PDT) for cancer treatment by increasing the delivery, targeting, and efficacy of photosensitizers (PSs). They can overcome limitations of traditional PDT, including insufficient tumor accumulation, poor solubility, and off-target effects. The Adequate delivery and proper therapeutic efficacy of many PSs are difficult due to their poor water solubility. Some nanomaterials, such as gold and silver nanoparticles, can be used to conjugate or encapsulate with these PSs, thereby enhancing their solubility, stability, and bioavailability.
  • Methods: In this review article, the current state-of-the-art of the importance of metal nanocarriers in cancer photodynamic therapy is discussed
  • Results: Metal nanoparticles can be functionalized with targeting molecules, such as peptides and antibodies. These ligands can selectively bind to cancer cells or tumor blood vessels, thereby minimizing damage to healthy tissues. On the other hand, metal nanoparticles can be designed to increase their penetration into solid tumors, addressing the challenge of limited tissue penetration of some PSs. This is possible by optimizing the size of the nanoparticles and their surface characteristics. Metal nanocarriers can be used to release the PSs in a controlled manner, improving the therapeutic window. In addition, some metal nanoparticles can act as photosensitizers themselves or enhance the activity of PSs in generating reactive oxygen species (ROS), upon light irradiation. It has been reported that MnO2 nanoparticles catalyze the decomposition of endogenous H2O2 into O2, decreasing tumor hypoxia and enhancing the efficacy of PDT. Among the various metal nanoparticles, gold nanoparticles (AuNPs) and silver nanoparticles (AuNPs), due to their unique optical properties and ease of functionalization, are widely used in PDT applications.
  • Conclusion: Metal nanoparticles have unique properties that allow high PS loading, increase PS absorption into the tumor site, and thereby promote the efficacy of PDT
  • Keywords: Photodynamic therapy, metal nanoparticle, cancer, nano drug delivery