Research Highlight

Red seaweed polymer helps make antimicrobial coating

doi:10.1038/nindia.2018.154 Published online 26 November 2018

Researchers have synthesised a polymer-coated nanocomposite that can prevent specific bacteria from forming biofilms on medical devices and in packaged food, making it potentially useful for blocking disease transmission through the biofilms1.

Microorganisms such as bacteria and fungi form biofilms that form on medical devices and contaminate packaged food. Such biofilms trigger infectious diseases that are difficult to treat with conventional antibiotics.

In their search for an alternative way to inhibit the growth of biofilm-forming pathogenic bacteria, scientists from the Indian Institute of Technology in Roorkee, India, synthesised the nanocomposite by capping the silver nanoparticles with carrageenan, a red-seaweed-derived polymer, using microwave radiation. They then tested the efficiency of the nanocomposite in blocking the growth of biofilm-forming pathogenic bacteria.   

The team, led by Krishna Mohan Poluri, found that the nanocomposite showed excellent antimicrobial activity against Staphylococcus aureus and Pseudomonus aeruginosa – two pathogenic bacteria that can form biofilms. Since the polymer has antifungal, antiviral and anticancer properties, the nanocomposite can be used to develop antimicrobial wound-healing ointments, and anticancer and antiviral agents. 

Unlike previously made silver nanocomposites that are only stable for two months, the polymer-coated nanocomposite remained stable for up to six months. Besides being biocompatible, the edible polymer can easily form gels, suggesting its potential as antimicrobial food-packaging and coating materials. 

The nanocomposite is also a potential cheap agent for treating chronic wounds such as pressure sores and diabetic ulcers caused by biofilms, says Poluri.


1. Goel, A. et al. Microwave assisted κ-carrageenan capped silver nanocomposites for eradication of bacterial biofilms. Carbohydr. Polymer. (2018) doi:10.1016/j.carbpol.2018.11.033