I wish you all happy and prosperous new year

Hoping to come up with great research updates in Nanotechnology to all

in this New Year 2014

Cancer Immunotherapy - Breakthrough of the year

"This year marks a turning point in cancer, as long-sought efforts to unleash the immune system against tumors are paying off - even if the future remains a question mark" stated by Jennifer Couzin-Frankel in the article published in Science on 20th December, 2013. With the ending of this year the Science magazine has surveyed the outstanding works done in the whole year. Out of many speculations and expectations, the panel chose Cancer Immunotherapy as the breakthrough of this year. Is it really worth to mention as breakthrough? Let’s see.

"Cancer", one word that kill the patient psychologically than the actual unwanted mass of cells in his/her body. The patients have in mind that day by day they are reaching to the end of their life. May be this can be avoided in the developed countries but it is prevalent in developing and underdeveloped countries. Novel therapeutic ways, targeting sites, therapeutic materials are being explored from a long time by researchers around the world with the millions of dollars as funding from the governments. Still for the researchers’ the disease is a mystery.

The panel has found some light in this deep dark unsolved puzzle for decades or say centuries! So, the breakthrough of this year "Cancer Immunotherapy" is the new field where the immune system is treated to kill cancer cells. Up to now the cancer cells are treated directly without affecting the immune system. This is a strategy where, say, ‘x’ is treated to kill y.  ‘x’ will signal a cascade of changes that result in the killing of ‘y’ rather than directly giving a molecule to kill ‘y’. Though this kind of treatment strategy is new, it is working. In this article, published in science, the author pointed some potential antibodies that target different sites on the T-Cells. They are Cytotoxic T-lymphocyte antigen 4 (CTLA-4), Programmed death 1 (PD 1) and Chimeric antigen receptor (CAR) therapy. 

The pink color antibodies are binding to the blue color receptors

signalling a cascade of events killing the cancer cells

(J Couzin-Frankel Science 2013;342:1432-1433)

Courtesy: Science magazine (AAAS)

The basic working principle of all these therapies is to target the T-cells with the antibodies to specific receptor marker on the T-cells. These antibodies block the targeted receptors and then signal a cascade of events that result in the killing of cancer cells. The clinical trials done on these strategic treatment modalities showed successful development in the patient’s survival rate and decrease in the tumor size. The recurrence of the disease is also decreased significantly. The peculiarity of these treatment modalities is that they can be used in any kind of tumors either benign or metastasis without potential side effects. The researchers are trying to decipher the mechanism of activity, the role of various molecules in killing the cancer cells.

Hoping for a cancer free society, the Cancer Immunotherapy, breakthrough of the year (agreeing worth to mention as breakthrough) should be materialized and also available to millions of cancer patients around the world. 

I wish you all Happy New Year.

Layer by Layer nanocarriers for Drug Delivery

     The Erlich's "Silver Bullet" is the final goal for any drug delivery researcher to accomplish. The development of various engineered nanocarrier systems for the delivery of drugs to the specific diseased locations in the body possess fresh challenges every time. The stability of the nanocarrier is very important inside the body. The carrier when injected into the blood stream it should not be degraded or dissolved immediately. At the same time it should not elicit any immune response. Most importantly, the carrier should not leak the drug until it reach the target site. To attain these basic but important things, researchers mostly chose the systems that have the stable charge distributed all over the carrier system. Research showed that the positive charged systems elicit immune response at a faster rate compared to negative and neural charged carriers.

     While designing a carrier for a particular drug the architecture of the carrier are very important. The shape and nature of the carrier plays an important role. Spherical carrier of different chemical nature like polymers, liposomes, nanoparticles are widely exploited. The polymer drug carriers are mainly used in the cases where the drug has to be released for a long time. For the case of liposomes, it is burst release or quick release and their life time at the targeted site is less. These carrier choices, to achieve specific duties, helps in enhancing the effectiveness of the carrier and also decrease the number of drug dosage times for the patient.

     Though these carriers seems to be promising, still there is room to increase their efficiency of drug loading and drug targeting particularly DNA or si-RNA targeting. The polymers such as Poly-L-Lysine, Polyethyleneimine etc are widely used to deliver these genetic material. These polymers are positive charged polymers that form tight complexes with the negatively charged DNA or si-RNA. A more protection is needed for this genetic material from the surrounding molecules and enzymes that degrade these once injected into the blood stream. A new approach of designing the delivery carriers to overcome these problems is reported recently. The layer-by-layer approach for the delivery of genetic material is reported by Deng et al.,  published in ACS Nano. 

                                                                         The cartoon showing the Layer-by-Layer designed drug delivery carrier system

Such engineered carrier systems are the future for a sustained, stable and effective delivery of the load to the targeted site.

Reference:

Zhou J. Deng, Stephen W. Morton, Elana Ben-Akiva, Erik C. Dreaden, Kevin E. Shopsowitz, Paula T. Hammond†, Layer-by-Layer Nanoparticles for Systemic Codelivery of an Anticancer Drug and siRNA for Potential Triple-Negative Breast Cancer Treatment. ACS Nano 7 (2013) 9571-9584.