Theranostics 2018; 8(19):5231-5245. doi:10.7150/thno.25286 This issue

Research Paper

Photodynamic therapy at ultra-low NIR laser power and X-Ray imaging using Cu3BiS3 nanocrystals

Srivani Veeranarayanan1*, M. Sheikh Mohamed1,2*, Aby Cheruvathoor Poulose1*, Masuko Rinya3, Yasushi Sakamoto4, Toru Maekawa1,2, D. Sakthi Kumar1,2 ✉

1. Bio-Nano Electronics Research Centre, Toyo University, Kawagoe, 350-8585, Japan
2. Graduate School of Interdisciplinary New Science, Toyo University, Kawagoe, 350-8585, Japan
3. JEOL Ltd. Otemachi Nomura Bldg.13F, 2-1-1, Otemachi, Chiyoda, Tokyo, 100-0004, Japan
4. Biomedical Research Centre, Division of Analytical Science, Saitama Medical University, Saitama 350-0495, Japan
* Equal contributing Authors

This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) license ( See for full terms and conditions.
Veeranarayanan S, Mohamed MS, Poulose AC, Rinya M, Sakamoto Y, Maekawa T, Kumar DS. Photodynamic therapy at ultra-low NIR laser power and X-Ray imaging using Cu3BiS3 nanocrystals. Theranostics 2018; 8(19):5231-5245. doi:10.7150/thno.25286. Available from

File import instruction


Graphic abstract

Materials with efficient potential in imaging as well as therapy are gaining particular attention in current medical research. Photodynamic therapy (PDT) has been recently recognized as a promising treatment option for solid tumors. Still, most of the nanomaterial-based PDT modules either employ an additional photosensitizer or require high power laser sources. Also, they suffer from a lack of responsiveness in the near-infrared (NIR) region. Nanomaterials that could realize PDT independently (without any photosensitizer), at safe laser dose and in the deep tissue penetrative NIR region would definitely be better solid tumor treatment options.

Methods: Herein, Cu- and Bi-based bimetal chalcogenide (Cu3BiS3), with absorption in the NIR region was developed. High-performance PDT of cancer and high-contrast x-ray imaging of tumor were performed in vivo. Biocompatibility of the NCs was also assessed in vivo.

Results: The highlight of the results was the realization of ultra-low dose NIR laser-mediated PDT, which has not been achieved before, leading to complete tumor regression. This could be a breakthrough in providing a pain- and scar-less treatment option, especially for solid tumors and malignant/benign subcutaneous masses. Though the NCs are active in the photo-thermal therapy (PTT) regime as well, focus is given to the exciting aspect of extremely low power-induced PDT observed here.

Conclusion: Their extended in vivo biodistribution with commendable hemo- and histo-compatibilities, along with imaging and multi-therapeutic capabilities, project these Cu3BiS3 NCs as promising, prospective theranostic candidates.

Keywords: photodynamic therapy, x-ray contrast imaging, reactive oxygen species, near-infrared laser, anticancer therapy