Wei Chen talks with
ScienceWatch.com and answers a few questions about
this month's Fast Breaking Paper in the field of Materials
Article Title: Nanoparticle fluorescence based
technology for biological applications
Journal: J NANOSCI NANOTECHNOL
Year: MAR 2008
* Univ Texas Arlington, Dept Phys, POB 19059, Arlington, TX
* Univ Texas Arlington, Dept Phys, Arlington, TX 76019 USA.
Why do you think your paper is highly
This is a review article that summarized the research projects undertaken
in my lab. It also introduced several related activities from among other
groups. Several of our projects have been of interest to public readers.
This paper contains much new information and I think this may have been why
it has been highly cited.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
It describes new concepts and methodologies, particularly the concept of
nanoparticle self-lighting photodynamic therapy for cancer treatment, the
concept of combining photodynamic therapy and radiation therapy for deep
cancer treatment, and the applications of nanoparticle photosensitizers for
cancer treatment. These are brand new approaches in nanotechnology.
Would you summarize the significance of your paper in
In this paper, we introduced several new developments in nanotechnology for
biological applications. For example, nanoparticle-based photodynamic
therapy is one of the most exciting approaches described in this article.
The goal is to find an efficient cancer therapy by developing X-ray
luminescence nanoparticles as a light source for photodynamic therapy.
Photodynamic therapy has been designated as a "promising new modality in
the treatment of cancer" since the early 1980s. Light must be delivered in
order to activate photodynamic therapy. Most drugs used for photodynamic
therapy require ultraviolet or blue light for activation. Unfortunately,
ultraviolet and blue light have minimal penetration into tissue and their
application for deep cancer therapy is a problem.
"...the slowing economy in the USA
has really affected the funding of many new
To solve this problem and also to enhance the treatment for deep cancers,
we proposed a new photodynamic therapy system in which the light is
generated by X-ray luminescence nanoparticles. The X-ray luminescence
nanoparticles and afterglow nanoparticles are attached to photoactive drugs
and, when the nanoparticle-drug systems are targeted to the tumor and are
stimulated by an X-ray during radiotherapy, these nanoparticles will
generate light (energy) which activate the drugs for photodynamic therapy.
In this case, no direct light delivery to the tumor is necessary and very
low doses of radiation are needed. In this modality, the radiation and
photodynamic therapies are combined and occur simultaneously, so that the
tumor destruction will be more efficient. More importantly, it can be used
for deep tumor treatment, as X-rays can penetrate deeply into the tissue.
Once demonstrated, this will provide a simple but more efficient modality
for breast cancer treatment.
How did you become involved in this research, and were
there any problems along the way?
I have been working on nanotechnologies for the past 15 years. My original
work concentrated on trying to use quantum dots for in vivo
imaging, with a concentration on the challenge of light penetration. I also
have experience with the design and synthesis scintillation measurement for
I knew light delivery was also a challenging issue for photodynamic
therapy, just like in vivo optical imaging. I then arrived at the
idea to combine photodynamic therapy with radiation therapy through
scintillation nanoparticles for deep cancer treatment.
Photodynamic therapy is not new, nor is radiation therapy, but the
combination of both through scintillation nanoparticles is new and
potentially important for deep cancer treatment. I introduced the concept
in a paper published in the Journal of Nanoscience and
Nanotechnology in 2006. (Wei Chen and Jun Zhang, "Using Nanoparticles
to Enable Simultaneous Radiation and Photodynamic Therapies for Cancer
Treatment," Journal of Nanoscience and Nanotechnology 6:
1159-66, April, 2006).
Initial results of the studies have been promising. But before
"nanoparticle self-lighting photodynamic therapy" becomes a clinical
reality, researchers must overcome two main challenges: 1) they need to
develop a class of water-soluble scintillation nanoparticles with very high
quantum efficiencies of X-ray luminescence, and 2) they need to improve the
targeting capabilities of the nanoparticle-photosensitizer
compound—but this is a challenge for all drug-based cancer
Most recently, we've used afterglow nanoparticles for photodynamic therapy
activation. This is a good solution for improving efficiency since
afterglow nanoparticles will maintain their luminescence for a certain
period of time after activation. In this case, the radiation dose will be
reduced exponentially. This new concept is also introduced in a recent
publication: Chen, W. "Nanoparticle self-Lighting photodynamic therapy for
cancer treatment," J. Biomed. Nanotechnol 4: 369-76, 2008.
Where do you see your research leading in the
This concept is getting more popular and has become intriguing to many
investigators. I think this will become quite a hot area during the next
decade and that products for practical applications will, sooner or later,
One of our recent review papers has appeared on the ScienceDirect
"25 Hottest Articles" list for October—December, 2008: (Juzenas, P.,
et al.,"Quantum dots and nanoparticles for photodynamic and
radiation therapies of cancer," Advanced Drug Delivery Reviews
15: 1600-14, December 2008).
By the way, many cancer patients and/or their families have contacted me
directly and enquired as to the timing for this new modality to become
available for patient treatment. I have sensed this urgent need and that is
the key motivation for my research.
Do you foresee any social or political implications for
Although there are no obvious political implications for my research, the
slowing economy in the USA has really affected the funding of many new
Wei Chen, Ph.D.
Department of Physics
The University of Texas at Arlington
Arlington, TX, USA