Navigation Links
Self-assembled nano-sized probes allow Penn researchers to see tumors through flesh and skin

Nano-sized particles embedded with bright, light-emitting molecules have enabled researchers to visualize a tumor more than one centimeter below the skin surface using only infrared light. A team of chemists, bioengineers and medical researchers based at the University of Pennsylvania and the University of Minnesota has lodged fluorescent materials called porphyrins within the surface of a polymersome, a cell-like vesicle, to image a tumor within a living rodent. Their findings, which represent a proof of principle for the use of emissive polymersomes to target and visualize tumors, appear in the Feb. 7 online early edition of the Proceedings of the National Academy of Science.

"We have shown that the dispersion of thousands of brightly emissive multi-porphyrin fluorophores within the polymersome membrane can be used to optically image tissue structures deep below the skin ?with the potential to go even deeper," said Michael J. Therien, a professor of chemistry at Penn. "It should also be possible to use an emissive polymersome vesicle to transport therapeutics directly to a tumor, enabling us to actually see if chemotherapy is really going to its intended target."

This work takes advantage of years of effort in the Therien laboratory focused on the design of highly fluorescent compounds. Polymersomes, which were developed by Penn professors Daniel A. Hammer and Dennis Discher in the mid-1990s, function much like the bilayered membranes of living cells. Whereas cell membranes are created from a double layer of fatty phospholipid chains, a polymersome is comprised of two layers of synthetic co-polymers. Like a living cell, the polymersome membrane has a hydrophobic core. The study shows that the fluorophores evenly disperse within this core, giving rise to a nanometer-sized light-emitting structure.

"These polymers are also larger than phospholipids, so that there is enough space for the fluorophores, which are larger than the average molecule that is found inside cell membranes," said Hammer, professor and chair of the Department of Bioengineering at Penn's School of Engineering and Applied Sciences. " Another feature that makes emissive polymersomes so useful is that they self-assemble. Simply mixing together all component parts gives rise to these functional nanometer-sized, cell-like vesicles."

In their study, the researchers demonstrate how they can use these emissive polymersomes to target markers on the surface of a specific type of tumor cells. When exposed to near-infrared light, which can travel through tissue, the fluorophores within the polymersome respond with a bright near-infrared signal that can then be detected.

"The fluorophores function like reflectors stuck in the spokes of a bicycle tire," Therien said. "When this structure absorbs light, it gives rise to an intense, localized fluorescence signal that is uniquely suited for visualizing living biological systems."

According to Therein, there is keen interest in developing new technology that will enable optical imaging of cancer tissue, as such technology will be less costly and more accessible than MRI-based methods and free of the harmful side effects associated with radioactivity. In this imaging system, the flourophores can also be tuned to respond to different wavelengths of near-infrared light. This sets the stage for using emissive polymersomes to target multiple cancer cell-surface markers in the body simultaneously.

Emissive polymersomes perform much like in vivo imaging systems that use semiconductor-based "quantum dots." These quantum dots, however, are hard matter, which could collect within the circulatory system, potentially causing a stroke. According to the Penn researchers, brightly emissive polymersomes define the first nanotech optical imaging platform based on non-aggregating "soft matter" (polymers and porphyrins) and hence have enormous potential in biomedicine.


'"/>

Source:University of Pennsylvania


Related biology news :

1. Self-assembled DNA buckyballs for drug delivery
2. Products containing specific probes for detecting alternative splice forms protected
3. Smart nanoprobes light up disease
4. UC Davis researchers use heated nanoprobes to destroy breast cancer cells in mice
5. York mathematician probes geometric route to combat viruses
6. Researchers find how protein allows insects to detect and respond to pheromones
7. Enzyme allows B cells to resist death, leading to leukemia
8. Tiny scaffolding allows stem cells to become working fat cells
9. Technique may allow cancer patients to freeze eggs, preserving fertility before starting treatment
10. PET/CT can identify new cancer lesions at early stage, allowing for prompt treatment
11. Looks matter to female barn swallows
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/11/2017)... 2017 No two people are believed ... New York University Tandon School of Engineering and ... that partial similarities between prints are common enough ... phones and other electronic devices can be more ... lies in the fact that fingerprint-based authentication systems ...
(Date:4/5/2017)...  The Allen Institute for Cell Science today announces ... portal and dynamic digital window into the human cell. ... application of deep learning to create predictive models of ... a growing suite of powerful tools. The Allen Cell ... publicly available resources created and shared by the Allen ...
(Date:4/4/2017)... --  EyeLock LLC , a leader of iris-based identity ... and Trademark Office (USPTO) has issued U.S. Patent No. ... iris image with a face image acquired in sequence ... th issued patent. "The issuance ... multi-modal biometric capabilities that have recently come to market ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... October 11, 2017 , ... ... Andi Purple announced Dr. Suneel I. Sheikh, the co-founder, CEO and chief research ... Inc. has been selected for membership in ARCS Alumni Hall of Fame ...
(Date:10/11/2017)... ... 11, 2017 , ... Personal eye wash is a basic first aid supply for any work ... which eye do you rinse first if a dangerous substance enters both eyes? It’s one ... with its unique dual eye piece. , “Whether its dirt and debris, or an ...
(Date:10/11/2017)... ... October 11, 2017 , ... Proscia Inc ... hosting a Webinar titled, “Pathology is going digital. Is your lab ready?” with ... adoption best practices and how Proscia improves lab economics and realizes an increase ...
(Date:10/11/2017)... LAGUNA HILLS, Calif. , Oct. 11, 2017 /PRNewswire/ ... London (ICR) and University of ... tool to risk-stratify patients with multiple myeloma (MM), in a ... . The University of Leeds is ... Myeloma UK, and ICR will perform the testing services to ...
Breaking Biology Technology: