Nanoparticles Yield Safer Light-Activated Cancer Therapy

Sep 27, 2007

Photodynamic therapy, in which light activates a chemical known as a photosensitizer, triggering the production of cell-killing reactive oxygen, has proven itself as an effective therapy for a limited number of cancers.

Oncologists have long suspected that photodynamic therapy could find broader use if only there was some way to limit the accumulation of photosensitizer molecules to tumors, sparing healthy tissue from unintended damage. Now, using modified silica nanoparticles, a team of investigators at the State University of New York, Buffalo, has developed a photosensitizer delivery method that has the potential to target tumor cells specifically.

Paras Prasad, Ph.D., principal investigator of one of the National Cancer Institute's Cancer Nanotechnology Platform Partnerships, heads the research effort that is aiming to use nanotechnology to make photodynamic therapy safer and more effective. His group has approached this problem by using porous silica nanoparticles modified in such a way as to form a strong chemical bond between the nanoparticles and the photosensitizer molecules. When exposed to light, the permanently entrapped photosensitizer still produces reactive oxygen molecules that can diffuse out of the nanoparticles through their porous silica shells.

The investigators found, too, that human colon cancer cells readily take up the photosensitizer-loaded nanoparticles. More importantly, shining light on these cells resulted in their death. In contrast, cells that were not exposed first to these nanoparticles suffered no ill effects from exposure to light. The investigators, who published their results in the journal Nano Letters, note that they are now developing a second-generation nanoparticle-photosensitizer construct that also includes tumor-targeting and imaging molecules.

This work, which was supported by the National Cancer Institute's Alliance for Nanotechnology in Cancer, is detailed in the paper, "Organically modified silica nanoparticles with covalently incorporated photosensitizer for photodynamic therapy of cancer." Investigators from the Roswell Park Cancer Institute also participated in this study.

This paper was published online in advance of print publication. An abstract is available through PubMed.

Source: National Cancer Institute

Explore further: Nano engineering advances bone-forming material

add to favorites email to friend print save as pdf

Related Stories

Introducing the multi-tasking nanoparticle

Aug 26, 2014

Kit Lam and colleagues from UC Davis and other institutions have created dynamic nanoparticles (NPs) that could provide an arsenal of applications to diagnose and treat cancer. Built on an easy-to-make polymer, these particles ...

Physicists create new nanoparticle for cancer therapy

Apr 16, 2014

A University of Texas at Arlington physicist working to create a luminescent nanoparticle to use in security-related radiation detection may have instead happened upon an advance in photodynamic cancer therapy.

Taking the fight into the enemy's territory

May 29, 2013

(Phys.org) —German researchers have developed a scheme for the preparation of nanoparticles that offer a highly versatile system for targeted drug delivery directly into diverse types of tumor cells.

Photo-immunotherapy boosts nanoparticle delivery to tumors

Feb 22, 2013

(Phys.org)—One of the main reasons that nanoparticles can boost the effectiveness of an anticancer drug while decreasing its toxicity is that they are able to accumulate at cancerous sites in the body through the abnormally ...

Nanoparticles + light = dead tumor cells

Jul 29, 2008

Medical physicists at the University of Virginia have created a novel way to kill tumor cells using nanoparticles and light. The technique, devised by Wensha Yang, an instructor in radiation oncology at the University of ...

Recommended for you

Making quantum dots glow brighter

53 minutes ago

Researchers from the University of Alabama in Huntsville and the University of Oklahoma have found a new way to control the properties of quantum dots, those tiny chunks of semiconductor material that glow ...

The future face of molecular electronics

1 hour ago

The emerging field of molecular electronics could take our definition of portable to the next level, enabling the construction of tiny circuits from molecular components. In these highly efficient devices, ...

'Small' transformation yields big changes

Sep 15, 2014

An interdisciplinary team of researchers led by Northeastern University has developed a novel method for controllably constructing precise inter-nanotube junctions and a variety of nanocarbon structures in ...

User comments : 0