Novel Drugs: Cancer Chemotherapy Using Nanoparticles developed with Nanotechnology May Reduce Harmful Side Effects of Antineoplastic Agents.

Chemotherapy for cancer is most of the time associated with one or the other harmful side effect of antineoplastic drugs as these chemotherapeutic drugs themselves are very cytotoxic, i.e. they damage normal cells too.
Antineoplastic drugs bring about their anticancer action by inhibiting cancerour cells growth by virtue of alkylation of nucleotides in cancerous cells or by inhibition of folic acid uptake by cancerous cells or by inhibiting cell division by binding with tubulin and microtubulin in a cancerous cells, it is likely that these drug are also absorbed in to normal tissues, leading to untoward serious cytotoxic effects , like kidney damage and nerve damage in chemotherapy with cisplatin, a drug of choice in most of anticancer chemotherapies.

A new drug delivery technique is being studied which uses Nanotechnology to deliver a cytotoxic drugs specifically directly in to the cancer cells , such drug delivery technique will be able to provide an efficient cancer chemotherapy that do not have much side effects as they pose today , it was observed that with nanoparticle drug delivery system the concentration of drug required to kill the cancerous cell is lesser than required in conventional chemotherapy therapy. As the drug is absorbed efficiently in to targeted cells and also drug is protected from degradation in blood stream , certain class of the anticancerdrugs are very unstable and stay in plasma for a very little time, therefor to achieve the required effect a higher concentration of drug may be required to be administrated.

Nanotechnology drug delivery system involves placing an anticancer drug in to a tiny particles known as nanoparticles which recognize cancerous cells and deliver the drug only to cancerous cells , as nanoparticles are very minute particles (1 nm to 100 nanometer) , the dose of drug required to kill the cancerous cells were also found to be very low as compared to conventional therapy . As the required effective dose it self gets reduced than conventional therapy , the harmful effect of anticancer drug are also likely to be reduced.

A team of scientists from the Massachusetts Institute of Technology and Brigham and Women's Hospital conducted study. They stored an prodrug of cisplatin (which is used in most of cancer chemotherapies) within nanoparticles which they developed to target a specific protein in cancerous cells in prostate gland.
After these prodrug loaded nanoparticles were absorbed by cancerous cells the prodrug was released in to the cancerous cells and was converted in to an active form . The team demonstrated that these prodrug carrying nanoparticles were able to kill cancer cells in culture more efficiently than the drug alone.

Study was conducted by researchers, led by Dr. Omid Farokhzad and Dr. Stephen Lippard, to study nanoparticle drug delivery system for an effective and safer option for chemotherapy in living animals. Their research work is published in Proceedings of the National Academy of Sciences, in Jan 2011 issue of the journal, the study was funded in part by NIH’s National Cancer Institute (NCI) and National Institute for Biomedical Imaging and Bioengineering (NIBIB).

By applying this drug delivery by nanoparticles they were able to shrink tumors in mice with smaller doses of the drug to reduce harmful side effects. Only 30% of the dose of prodrug of cisplatin was required to diminish the tumor by using the drug carrying nanoparticles, than that of standard dose of cisplatin as such.
Researchers initially studied different doses of nanoparticle bound drug in rats and mice, both the types of animals maintained their body weight and survived at higher doses of the drug when drug was delivered using nanoparticles than when injected without nanoparticles. It was also found that the kidney damage was less in rats which received the nanoparticle bound drug.

Also it was found that binding nanoparticles provided greater stability of cisplatin prodrug in blood stream than that of injected alone , after one hour about 77 % of prodrug was found in blood stream when it was delivered using nanoparticles compared to only 16% available drug in case of drug delivered without nanoparticles, cispaltin is very unstable drug and remains in blood for very short time , which calls for more dose to get the desired effect.

Rajarshi Patel