Carbon Na**tubes Purified/Modified to Deliver Chemo to Pancreatic Cancer Cells
 

Carbon Na**tubes Purified/Modified to Deliver Chemo to Pancreatic Cancer Cells
[IMG]http://cdn.medgadget.com/wp-content/uploads/2014/06/na**particles-for-pancreatic-cancer.jpg[/IMG]Rice researchers found that chemotherapy agents attached to na**tubes are too large to go through the pores of **rmal blood vessels (left), but small e**ugh to pass through the pores of cancer-related vessels. Once through, the customized na**tubes can be taken up by cancer cells to deliver their therapeutic cargoes. Courtesy of Rei Suzuki/University of Texas MD Anderson Cancer Center)


Pancreatic cancer is a vicious disease that attacks its victims with great speed, is hard to detect, and for which meaningful therapies are nearly***nexistent. Getting chemo ***** to reach pancreatic tumor cells with precision is a challenge. To overcome this, researchers at Rice University and MD Anderson Cancer Center have been testing a method that relies on carbon na**tubes to deliver chemo precisely into cancer cells, and then onward into the cells’ nuclei.

[IMG]http://cdn.medgadget.com/wp-content/uploads/2014/06/na**-side-2.jpg[/IMG]Laser confocal microscopy images show na**tubes combined with polyethyleneimine and fluorescent tags can be taken up by pancreatic cancer cells. The top image shows na**tubes with rhodamine B dye in the cells; the center image shows a DAPI-stained cell and the bottom image combines the two. Courtesy of Enrico Andreoli/Barron Group


The scientists used a technique called functionalization, which allows chemo agents to be attached to the na**tubes. Scientists also did a good deal of experimentation to discover what size tubes are best for the job. Turns out that 50 na**meters in length was ideal.

The tubes were flushed with chlorine to get rid of oxidizing iron particles that are used as a catalyst during the tubes’ creation. Additionally, the na**tubes had a polyethyleneimine (PEI) coating added to their surface, helping the tubes disperse and pass through cells walls and into the nucleus.*Shaking up the tubes, presumably using ultrasound, forces them to release their cargo and finally hit their target with a deadly strike from within. The researchers plan to begin testing the new tech**logy on mice who will have allografts of human tumors transplanted into them.

Some details from the study abstract:

High quality single-walled carbon na**tubes (SWNTs) were obtained following a new purification procedure, based on using Cl2 gas at high temperature. Cl2-treated SWNTs were fluorinated and modified with branched polyethyleneimine (PEI) to afford covalently functionalised PEI-SWNTs, which were then tested for cytotoxicity both in vitro (HPNE and BxPC3 pancreatic cell lines) and in vivo (BxPC3 xe**grafts from nude mice) to establish that functionalization with lower molecular weight PEI (600 and 1800 Da) achieved higher cell viability in MTT assay. A shortened version of the na**tubes, PEI(1800)-cut-SWNT (1800 Da branched PEI), was also prepared and tested for cellular internalization in BxPC3 ade**carci**ma cell line. Laser confocal imaging of the cells after incubation in the presence of RhoB-PEI(1800)-cut-SWNT (covalently labelled with rhodamine B) indicates that the PEI(1800)-cut-SWNTs can reach both the cytoplasm and nucleus of pancreatic cancer cells.

Study in Journal of Material Chemistry B: Preparation and evaluation of polyethyleneimine-single walled carbon na**tube conjugates as vectors for pancreatic cancer treatment…

More from Rice: Short na**tubes target pancreatic cancer…

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