Nanocarrier has improved the drug action in pancreatic cancer

Hi all. As I told in my previous blog, this is the second post regarding my work that recently published. Pancreatic cancer is the most aggressive of all cancers. The five year survival rate of a patient is less than 6 %. Out of 100 persons diagnosed with pancreatic cancer 85 persons are mortal. For treating of such an aggressive disease "Gemcitabine" is recommended as the standard chemotherapy with 1000 mg/meter square. The poor bio-availability of the drug inside tumor environment and rapid efflux mechanisms of pancreatic cancer cells are the prime reasons for the pancreatic cancer resistance towards gemcitabine. To over come this drawback, a nanocarrier that is biocompatible and biodegradable with sustained drug release shall be effective in treating pancreatic cancer.

Cartoon depicting the Gemcitabine (Green) loaded PLGA (grey) nanospheres

Our work, published in Materials Science and Engineering: Chemistry, discussed about gemcitabine loaded poly(Lactide-co-glycolide) (PLGA) nanospheres as an effective treatment modality for pancreatic cancer. We have encapsulated the drug into PLGA nanospheres by water-oil-water emulsion method and achieved 15 % of encapsulation which is higher compared to existing literature, as it is tough to load a hydrophilic drug into a hydrophobic polymer. The gemcitabine was proved in the literature to be present in the polymer chain foldings and crevices formed by polymer chains inside the PLGA nanospheres. The drug loaded gemcitabine PLGA nanospheres provided a sustained drug release for 41 days. The nanospheres showed the bulk erosion degradation which enhances the release of drug in a sustained manner. The nanospheres were taken into cells by non-energy dependent mechanism. The specific targeting using an antibody will facilitate specific cancer cell attack by the nanocarrier.

Overall the biodegradable and biocompatible PLGA with gemcitabine loaded inside shall be a promising nanocarrier for pancreatic cancer treatment.

Reference

L.R.Jaidev, Uma Maheswari Krishnan, Swaminathan Sethuraman, (2015)  Gemcitabine loaded biodegradable PLGA nanospheres for in vitro pancreatic cancer therapy Material Science and Engineering:C , 47, 40–47.

http://www.sciencedirect.com/science/article/pii/S0928493114007280 

Nanochains for the treatment of Cancer Micrometastasis

Cancer is the well known diseased state around the world with millions of people suffering from it. For researchers it is a heap of task to combat this disease. From several decades several treatment methods are in practice. Among them, surgery and chemotherapy are the highly recommending treatment methods. Physicians remove the tumor through surgery and then suggest the high dosage of tumor suppressing drugs also called chemotherapy. These methods can be followed when the tumor size is around 100 mm³, provided the tumor is benign and not metastatic.

What is with the metastatic tumor? The cancer cells detach from the solid benign tumors migrate to different organs in the body and grow into tumors. This state is called metastatic state. The cancer at this stage is highly resistant to treatment. It is difficult to remove the numerous tiny tumors by surgery because the size of these metastatic tumors is very less. Normally more lethal cancer like pancreatic cancer will be in metastatic stage by the time the physician detect the presence of cancer. Thus the treatment is very difficult and the chances of survival also very very less. Thus the mortality rate increases.

Researchers are trying different methods and novel materials to treat this kind of metastatic cancer. With the availability of the high end technology like nanotechnology, where the nano (10^-9m) sized materials are synthesized and exploited for different applications, there is scope to find some novel ways of treatment. A recent paper in Journal of controlled release during the january issue showed the new kind of nanomaterials called as nanochains are employed to treat the cancer state. The nanoparticles were loaded with drug and linked to the other nanoparticle by a covalent linkage. The authors found that these materials are highly penetrable to the deep locations of the tumor and releasing the drug will kill the cancer cells. Novel materials like these are crucial to combat diseases like cancer.

Reference: Journal of controlled release, vol. 173, 10 January 2014, Pages 51–58

Microparticles for brain drug delivery

The usage of nanoparticles for the therapeutic applications is in research for quite a long time. The fruits of the research are come out now. The clinical trails for various drug delivery formulations are in progress. The recent studies of the nanoformulations are well discussed in this article. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3260950/


Eventhough we have many liposome formulations, the commercialization of polymer nanodrug formulations hasn't seen light yet. The recent study of pennstate university research group has showed the sustained release of the microparticles for brain drug delivery. The blood brain barrier is the primary limitation step for any drug to enter into brain. The liposomes are widely used for brain drug delivery as they are having the lipid component which can easily enter into the brain than other formulations. But the draw back of liposomes is the burst release of the drug. Most of the drug will be released within the short period of time. This causes the patient has to take more doses at regular periods of time.The pennstate research group led by Dr. Mohammad Reza Abidian, assistant professor of bioengineering, chemical engineering and materials science and engineering has mentioned that "Brain tumors are one of the world's deadliest diseases," which needs to be addressed with a potential carrier system. Their work has been recently reported in Science daily. In their words. "We are trying to develop a new method of drug delivery," said Abidian. "Not intravenous delivery, but localized directly into the tumor site."
Current treatment already includes leaving wafers infused with the anti-tumor agent BCNU in the brain after surgery, but when the drugs in these wafers run out, repeating invasive placement is not generally recommended.
"BCNU has a half life in the body of 15 minutes," said Abidian. "The drug needs protection because of the short half life. Encapsulation inside biodegradable polymers can solve that problem."

The research groups around the world are trying to have a suitable carrier system that can cure the brain cancer. The work done by pennstate university is one of the good work in a new approach. Hope new thinking in new ways provide the solution to the long suffering problem.

Courtesy: www.sciencedaily.com

Drug delivery in Cancer

Cancer is an unanswerable question for researchers around the world from many decades. Exploring wide areas of biology, medicine and interdisciplinary fields like nanotechnology is going on to find a suitable molecule to kill cancer. The prescription of drugs (chemotherapy) to cancer patients by physicians across the globe after tumor removal is the current treatment modality. So the drugs play an important role in the treatment of cancer. The effectiveness of the drugs is limited while the side effects are more. But patients, as there is no other go, are ready to take these drugs.

From the last decade, the advent of nanotechnology in the delivery of medicine has paved the way for a new field called “Drug Delivery”. The main objective of this field is to develop various nanoformulation (a drug loaded nanocarrier) that is targeted to the specific diseased site, stay for a longer time in the body and minimizing side effects. Not every nanoformulation will fulfill all these three, but most of them will.

A recent development from Mc Neil’s Lab, part of the federally funded research and development center operated by SAIC-Frederick for the National Cancer Institute, worked with a drug company to reformulate TNF-alpha by coupling it with gold nanoparticles. Using the nanotechnology-enhanced protein, it appears possible to safely inject up to three times the amount that had been lethal with previous versions. The modified drug has been through a Phase 1 clinical trial and is entering Phase 2[1].

In future we can expect much more will come from many labs around the world and hope for a cancer free society.

[1] courtesy from Science daily, New Delivery for Cancer Drugs,May 7, 2013.