23
Oct 11

Scientist proves potential of new nanoparticle design for cancer therapy

Drug delivering Nanoparticle

A new type of nanoparticle developed in the laboratories at the University of North Carolina has shown potential for more effective delivery of chemotherapy to treat cancer. Wenbin Lin, PhD, Kenan Distinguished Professor of Chemistry and Pharmacy, and colleagues report their finding in the Sept. 14, 2011 issue of Angewandte Chemie.

In laboratory studies, Lin and colleagues developed and tested a new type of nanoparticle that can deliver larger amounts of a drug and will not leak the drug as the particle circulates through the blood stream on its way to the target.

In the proof-of-concept experiments, they tested the nanoparticle’s ability to deliver therapeutic doses of the chemotherapy drug oxaliplatin to colon and pancreatic tumors. The oxaliplatin-based particles showed significant growth inhibition of pancreatic tumors that are extremely difficult to treat. The nanoparticle has two to three times therapeutic efficacy over oxaliplatin.

The nanoparticle is different from other nanoparticles in its very high drug loading and in the ability to release in the chemotherapeutics in a controlled fashion. The release of therapeutic cargoes depends on the naturally occurring molecules that are more abundant in many tumors.

Lin explains, “The polysilsesquioxane (PSQ) particle we have developed carries extremely high loadings of oxaliplatin-based chemotherapeutics. The particles are stable under normal physiological conditions, but can be readily reduced to release the platin cargoes in highly reducing tumor microenvironments that have high concentrations of reducing agents. As a result, they have very little background release and are more easily targeted to tumors than most existing particles. We need to thoroughly determine the pharmacokinetics and other important properties of the PSQparticle in order to translate this particle platform to the clinic.”

Via PsyOrg.com


08
Oct 11

Tumours grow their own blood vessels

For some tumours at least, a lack of host blood supply is not a problem.

Finding explains failure of drugs that target host vasculature.

Alla Katsnelson

Tumours don’t just rely on their host’s blood vessels for nourishment — they can make their own vasculature, according to two independent studies from the United States and Italy. The findings offer an explanation for why a class of drug once heralded as a game-changer in cancer treatment is proving less effective than had been hoped.

Almost four decades ago, Judah Folkman, a cell biologist at Harvard Medical School in Boston, Massachusetts, proposed that tumours were dependent on the blood vessels surrounding them, and that choking off that blood supply would kill the cancer1. Bevacizumab (Avastin), the first drug to block blood-vessel growth, was approved in 2004, but it and other ‘angiogenesis inhibitors’ have proved disappointing in the clinic, extending patients’ lives for at best a few months.

Continue reading →


08
Oct 11

This Is the Future of the Fight Against Cancer

Those tiny black dots are nanobots delivering a lethal blow to a cancerous cell, effectively killing it.

Look close. You may be staring at the end of cancer.

Those tiny black dots are nanobots delivering a lethal blow to a cancerous cell, effectively killing it. The first trial on humans has been a success, with no side-effects:

It sneaks in, evades the immune system, delivers the siRNA, and the disassembled components exit out.

Those are the words of Mark Davis, head of the research team that created the nanobot anti-cancer army at the California Institute of Technology. According to a study to be published in Nature, Davis’ team has discovered a clean, safe way to deliver RNAi sequences to cancerous cells. RNAi (Ribonucleic acid interference) is a technique that attacks specific genes in malign cells, disabling functions inside and killing them.

The 70-nanometer attack bots—made with two polymers and a protein that attaches to the cancerous cell’s surface—carry a piece of RNA called small-interfering RNA (siRNA), which deactivates the production of a protein, starving the malign cell to death. Once it has delivered its lethal blow, the nanoparticle breaks down into tiny pieces that get eliminated by the body in the urine.

The most amazing thing is that you can send as many of these soldiers as you want, and they will keep attaching to the bad guys, killing them left, right, and center, and stopping tumors. According to Davis, “the more [they] put in, the more ends up where they are supposed to be, in tumour cells.” While they will have to finish the trials to make sure that there are no side-effects whatsoever, the team is very happy with the successful results and it’s excited about what’s coming:

What’s so exciting is that virtually any gene can be targeted now. Every protein now is druggable. My hope is to make tumours melt away while maintaining a high quality of life for the patients. We’re moving another step closer to being able to do that now.

Hopefully, they will be right.

via…

 


03
Oct 11

Nanoparticles seek and destroy glioblastoma in mice

Scientists have combined a tumor-homing peptide, a cell-killing peptide, and a nanoparticle. When administered to mice with glioblastoma that could not otherwise be treated, this new nanosystem eradicated most tumors in one model and significantly delayed tumor development in another.

Read the full article…  Nanoparticles seek and destroy glioblastoma in mice.