Nanotechnology delivers lethal dose of drug to prostate cancer cells

Nanotechnology delivers lethal dose of drug to prostate cancer cells

Using a nanotech drug delivery method to target cancer cells is much more effective than using the drug by itself. In laboratory tests, nanoparticles that include a small molecule of nucleic acid that binds to a target molecule on prostate cancer cells were used to carry a lethal dose of the drug into the cancer cells without affecting cells lacking the cancer-specific target. From the National Cancer Institute’s Alliance for Nanotechnology in Cancer “Targeted Nanoparticles Boost Platinum-Based Anticancer Therapy“:

A research team from the Massachusetts Institute of Technology (MIT)-Harvard Center for Nanotechnology Excellence has custom-designed nanoparticles that can deliver the anticancer drug cisplatin specifically to prostate cancer cells. The nanoparticles are composed of two different polymers and are decorated with a nucleic acid aptamer that binds to the tumor marker prostate-specific membrane antigen. This aptamer ensures that the nanoparticles deliver their payload only to prostate cancer cells.

Stephen Lippard, Ph.D., and Robert Langer, Ph.D., MIT, and Omid Farokhzad, M.D., Harvard Medical School, led the team that developed this new formation of cisplatin. The investigators published their results in the Proceedings of the National Academy of Sciences of the United States of America [abstract].

To construct a stable nanoparticle that would only release its toxic cargo inside tumor cells, the investigators synthesized a modified version of cisplatin that includes a long hydrocarbon chain. As the nanoparticle forms, the hydrocarbon chain associates strongly with the hydrophobic chains of the polymer that forms the nanoparticle’s core. The researchers note that the hydrocarbon chain they chose optimizes both drug encapsulation and drug release inside tumor cells. Once the nanoparticle enters the cell, the modified drug is converted into its active form as a result of chemical conditions inside the cell.

Tests with human cancer cells growing in culture showed that these nanoparticles were taken up specifically by tumor cells and not by healthy cells. Nanoparticles lacking the targeting aptamer were not taken up either. These tests also demonstrated that the nanoparticles release their cargo over the course of 60 hours, providing a sustained lethal level of the drug inside the targeted cells. In addition, the nanoparticle formulation was approximately 100 times more effective at killing tumor cells than was cisplatin by itself.


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  1. Harry L. Cook December 4, 2008 at 10:08 am - Reply

    When will this be generally available?

  2. Jim Lewis December 5, 2008 at 2:21 am - Reply

    I don’t know, but experiments with cells in the laboratory are generally rather early in the drug development process, so I would guess this is more than a couple years away from becoming available.

  3. Gregory Bloom December 8, 2008 at 7:56 pm - Reply

    Pre-clinical testing on animals takes 1-3 years. Then, assuming it shows promise in animals, anywhere from 2-10+ years for phase I, II and III testing in humans. If all goes well, the drug manufacturer can then apply to the FDA. The FDA can camp on it for 6 months, and can require additional testing if there is some part of the results of the human trials that they don’t like. All in all, it takes anywhere from 3 to 13+ years for a drug to trudge through the pipeline.

    Personally, I wish the FDA would open a category of unapproved drugs with a big fat skull and crossbones on the label that warns the user that this stuff could kill you, or worse! The users would be allowed access to these unapproved drugs on condition that their situation is closely monitored, and that their results are communicated back to a central database which is available to the public. Also, such unapproved drugs would have to be made available free of cost. (That way the manufacturer has to continue getting formal approval before they can turn a profit). There are many people whose circumstances make it a no-brainer for them to be the first to gulp down some promising drug. Those that saw benefit would make it easier for others to follow in their choice, long before formal approval is completed. Sick people would have immediate access to possible cures, fresh from the lab. Drug manufacturers would gain an early ‘litmus test’ for whether their drugs are dramatically good or bad and could thus be more nimble in their pursuit of approval for winners.

  4. Anonymous December 25, 2008 at 12:48 am - Reply

    Seriously? Prostate cancer? Why not glioblastoma or something more worthwhile. And yeah, before you start, I know there are patients who are hormone-refractory or those that failed conventional surgery/radiotherapy. But survival benefits are notoriously difficult to prove in prostate cancer. Platinum compounds have been used very frequently in other cancers with much poorer survival. Why not try a model that will improve your chance of showing survival benefit? I think it’s time we helped out patients with lung cancer – small cell or non-small cell. They’ve been getting the shaft ever since cancer research began! I guess it’s about the stigma of “causing your illness”

  5. Anonymous April 2, 2009 at 5:43 am - Reply

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