Researchers at IIT-Guwahati have developed a new strategy to deliver chemotherapeutic drugs directly to the infected cells of a cancer patient, thereby significantly reducing side effects.

Explaining it, professor Debasis Manna of the Department of Chemistry said the researchers had two needs in the development of chemotherapy drugs — it must be targeted at the cancer cells and must be released by an external trigger whenever it is required.

“The problem with existing chemotherapeutic drugs is that they kill healthy cells of the body in addition to cancerous cells, leading to numerous undesirable side effects,” IIT-Guwahati said in a statement on Monday.

In fact, it is believed that cancer deaths are as much due to the side effects of chemotherapy as the disease itself, it added.

“There is worldwide research to overcome the drawbacks of secondary toxicity of chemotherapeutic drugs. Some strategies that are being explored include target-specific delivery of the drugs and on-demand delivery of appropriate drug doses to cancerous cells and tissues,” it said.

The molecules developed by the IIT-Guwahati researchers self-assemble as capsules to hold the drug, which then attaches only to cancer cells, the statement said.

“When infrared light is shone on it, the shell breaks and releases the encapsulated drug into the cancerous cell. The IIT-G scientists rightly believe that their approach would allow the development of drug carriers for chemotherapy with enhanced efficacy and negligible side effects,” it added.

The research papers have been co-authored by Manna, along with his research scholars Subhasis Dey, Anjali Patel, and Biswa Mohan Prusty among others.

Anti-cancer activities were carried out in collaboration with professors Siddhartha Sankar Ghosh and Plaboni Sen of IIT-Guwahati, and professors Arindam Bhattacharyya and Soumya Chatterjee of Calcutta University.

“The path-breaking results of this research have been published in prestigious journals of The Royal Society of Chemistry, including ‘Chemical Communications’ and ‘Organic and Biomolecular Chemistry’,” the statement said.

The premier technical institute said that the societal impacts of this work cannot be overstated given the number of cancer patients in India anticipated to be 30 million by 2025.

source/content: newindianexpress.com (headline edited)

The spherical vesicles, which can be delivered to immune cells, are expected to potentially trigger an immune response.

To combat tuberculosis, researchers at the Indian Institute of Science (IISc) have designed a new method under which a vaccine candidate for the disease can be delivered by making use of Outer Membrane Vesicles (OMVs). These spherical vesicles, which can be delivered to immune cells, are secreted by bacteria coated on gold nanoparticles. The deliverance is expected to potentially trigger an immune response to offer protection against TB.

Across the world, TB, which is caused by a bacterium called Mycobacterium tuberculosis, claims the lives of over a million people every year. Currently, BCG is the only effective vaccine against TB. It contains a weakened form of the disease-causing bacterium, which when injected into the bloodstream, produces antibodies which can help fight the disease.

However, the scientists have said that the BCG vaccine does not protect adolescents and adults as effectively as it does children. Prompted by this, Rachit Agarwal, Assistant Professor at the Centre for BioSystems Science and Engineering (BSSE), IISc, and his group worked on developing a potential subunit vaccine candidate that contains only parts of the infectious bacterium to stimulate an immune response.

Although other scientists had developed subunit vaccines based on a handful of proteins from the disease-causing bacteria earlier, they had not been effective in the treatment. Agarwal’s group decided to take a slightly varied approach and made use of OMVs — which are spherical membrane-bound particles released by some bacteria, and contain an assortment of proteins and lipids which could induce an immune response against the pathogen.

“They’re safer compared to a live bacterium, and since they are membrane-derived, they contain all kinds of antigens,” explained Agarwal, the senior author of the paper published in  Biomaterials Advances. The researchers further explained that while subunit vaccines typically only contain a limited number of antigens — bacterial proteins that can elicit an immune response in the host, the OMVs contain a variety of antigens, which can induce a better immune response.

“Mycobacterium-derived OMVs are usually unstable and come in different sizes, making them unsuitable for vaccine applications. But the OMVs coated on gold nanoparticles (OMV-AuNPs) by the IISc team were found to be uniform in size and stable. The researchers also found that human immune cells showed a higher uptake of OMV-AuNPs (gold nanoparticles) than of OMVs or gold nanoparticles alone”, said an IISc press release. 

According to Avijit Goswami, a former postdoctoral fellow at BSSE and one of the first authors of the study, the most challenging part was the production and scaling up of OMVs as it was a complex process. “To synthesise OMV-AuNPs, the OMVs and the gold nanoparticles are forced together through a 100 nm filter. The OMVs break up in the process and encapsulate the gold nanoparticles,” explained Edna George, a former postdoctoral fellow at BSSE, and co-first author of the study.

During this study, the immune cells, which were cultured in the lab, were treated with OMVs derived from a related bacterial species which does not cause disease in humans, called as Mycobacterium smegmatis. Furthering their research, the team plans to develop gold-coated OMVs derived directly from Mycobacterium tuberculosis. They will then test the same on animal models and carry the results forward for clinical applications.

“Such efforts could open up new avenues for the development of vaccines for other bacterial diseases as well”, the release said.

source/content: thehindu.com (headline edited)