The Indian Institute of Technology at Guwahati has developed nanomaterials derived from nature to deliver drugs inside the human body in a controlled and targetted manner. Such biocompatible vehicles could potentially carry chemotherapy drugs directly to the cancer cells, a statement issued by the Institute said.

A research team led by Dr. Biman B. Mandal, Associate Professor, Department of Biosciences and Bioengineering, along with Dr. Jadi Praveen Kumar, Dr. Rocktotpal Konwarh, Dr. Manishekhar Kumar and Mr. Ankit Gangrade have studied various types of nanomaterials for use as carriers in targeted drug delivery.

 A nanometre is one-millionth of a millimeter and nanomaterials are made of particles that are 100,000 times smaller than the diameter of a human hair. In chemotherapy, nanoparticles loaded with drugs can be targeted at tumor cells, bypassing healthy cells, thus avoiding non-specific biodistribution, drug resistance, and unwanted adverse effects. 

According to Dr. Mandal, IIT Guwahati research team has developed a hydrogel system made of silk and carbon nanotubes loaded with drug molecules for controlled release of drugs.  Hydrogels are polymeric networks that absorb huge volumes of water and swell. The high water content makes hydrogels similar to tissues, enhancing biocompatibility, and also allow easy encapsulation and release of drugs at targeted sites. The researchers combined silk with drug-loaded carbon nanotubes, which offered better mechanical strength to the silk hydrogels, in addition to enabling slow and controlled release of the drug at the target site. 

ÂOur injectable hybrid hydrogel system had pH, temperature, and near-infrared (NIR) light-dependent drug release properties, added Dr. Mandal. The work, the results of which were published recently in ACS Biomaterials Science & Engineering.  The hybrid hydrogel is injectable and designed to serve as a reservoir for anticancer drugs at the local site of the tumour. For technology, the team has applied for a patent. Ankit Gangrade has co-authored this paper with Dr. Mandal.

In an earlier study, Dr. Mandal and his team used bio-derived carbon nanodots as vehicles for drug delivery.  It is attractive to produce such nanodots from biological sources to avoid the use of toxic products, and there have been attempts to produce carbon nanodots from bread, jaggery, banana, and even milk. 

In an Indian twist to these attempts, the research team produced carbon nanodots from lassi, the popular yogurt-based drink.  The researchers heated store-bought lassi in the microwave oven for about six and a half minutes and separated the carbonized portion that contained carbon nanodots. The researchers then loaded the nanodots with a model drug compound called doxorubicin (Dox).  The Dox-loaded carbon nanoparticles released the drug in response to the change in acid content in the surrounding medium.  WhatÂs more, the drug was delivered into the target cell directly. 

Talking about the treatment methods for cancer, Dr. Biman B. Mandal, Associate Professor, Department of Biosciences and Bioengineering, IIT Guwahati, said, ÂAlthough conventional chemotherapy is one of the most widely used treatment methods for cancer, its drawbacks include poor bioavailability at the actual cancerous regions, which necessitates high-dose injections, and serious side effects that arise because the drugs destroy healthy cells along with the cancer cells in the body. Both these problems can be solved by delivering drugs exclusively to the target cancerous zones, and our silk-nanotube and nanodot based vehicles would serve as good carriers of such drugs.Â

The concept of targeted drugs is not new; German Nobel Laureate Paul Ehrlich proposed, in the early 1900s, the concept of ÂMagische Kugel, or magic bullet  a drug that can target the disease like a missile fired towards a target.  While early developments on targeted drugs focused on treating infections, the past two decades have seen a surge in the development of targeted drugs for cancer and other tumors.