Photo: Siddharth Kankaria / Research Matters
Over the last several decades, antibiotics have played a critical role in fighting infectious diseases caused by bacteria and other microbes. However, blatant misuse and overuse of these drugs has resulted in the bacteria becoming resistant to a wide range of antibiotics where it changes itself to eliminate the action of the antibiotics and thus renders the drug useless. A recent work by researchers at the Indian Institute of Science, Bangalore and the Bose Institute, Kolkata, has addressed the challenge of antibiotic resistance using nanotechnology.
The study, led by Prof. Hanudatta Atreya at the NMR Research Center, IISc, in collaboration with Prof. Anirban Bhuniya’s research group at the Bose Institute, Kolkata, used nanoparticles made of silver, and attached it chemically with an antimicrobial molecule. Usually, the nanoparticles degrade within a few hours to few days in solution. However, this combination of the nanoparticles with a peptide drug was found to enhance the stability of the nanoparticle beyond two months, was safe to use and also showed enhanced efficiency against bugs.
The team unearthed the nature of interaction between the nanoparticle and the antibiotic in the nano-drug combination at the atomic level for the first time. This was done using sophisticated Nuclear Magnetic Resonance technique that helps in drawing a detailed 3-D picture of the combination. “The peptide and the nanoparticle act in a touch-and-go kind of mechanism. The antimicrobial molecules come close to the relatively large spherical nanoparticle, touch it momentarily and then move away like bees swarming around a bee-hive”, explains Prof. Atreya.
“The activity of the nanoparticle-peptide combination was found to be higher than the action of the individual components (nanoparticle and the peptide) alone, implying a synergistic action”, he adds. Interestingly, one can also pack a large number of antimicrobial drug molecules with one nanoparticle, achieving high density of these molecules that can be delivered at particular location acting as an antimicrobial “bomb”. These targeted bombs damage the bacterial membrane with increased potency as compared to the free non-conjugated drugs, thus resulting in better efficiency.
“It is difficult for the bacteria to develop resistance to these types of drugs because the mechanism of the combo-drug is different from the way the conventional antibiotics work. Thus, these types of drugs will be more effective”, opines Prof. Atreya. This research is likely to open up new avenues in the field of nanomedicine.