Context-Researchers at the Indian Association for the Cultivation of Science (IACS) Kolkata have used a using naturally occurring nucleoside molecule cytidine to self-assemble into a hydrogel in the presence of silver acetate and phenyl boronic acid

Antibacterial activity

• The hydrogel possessing i-motif DNA-like structure was found to exhibit antibacterial activity against Gram-negative bacterial strains such as E. coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and multidrug-resistant Morganella morganii
• While silver is known to have antibacterial property, it may not be used due to its toxicity. But when silver acetate was incorporated in the hydrogel the toxicity was reduced and thus suitable for treating bacterial infections. The hydrogel containing silver acetate was found to be non-toxic to normal kidney epithelial cells and red blood cells.

How it works

• silver-containing hydrogel was capable of killing E. coli. The hydrogel reduced the cell size of the E. coli and disrupted its cell membrane, leading to leakage of cellular contents

Physical properties

Thixotropic property

• Hydrogel exhibits thixotropic property — changes from a gel to a sol phase when subjected to mechanical shaking or stirring. When allowed to stand, it returns to its original gel phase. The hydrogel is also pH responsive. While being stable between pH 3 and 6, it becomes unstable at more acidic or alkaline pH.

Drug delivery

• The hydrogel can be used for drug delivery applications by using external stimuli such as mechanical stress or by changing the pH . The low pH of the gel is also another contributing factor for its intrinsic antibacterial activities.
• The researchers loaded the hydrogel with cancer drug doxorubicin and made the gel release the drug by subjecting it to mechanical shearing and changing the pH. 

The Indian Association for the Cultivation of Science (IACS)

• It is a society registered under Act XXI of 1860 and the corresponding State Act viz. the West Bengal State Registration Act 1961,
• The Institute is run by the Governing Council, which is the apex policy making body. The Director is the chief executive officer of the Institute and runs the business of the Association under the supervision of the Council.

The Governing Council plays the following important role.

• The Council is the executive authority of the Association and would constitute the apex body responsible for smooth running of the organization. The Council will ensure that the transactions in the Association are in accordance to the Regulations and Bye-Laws contained herein. 
•  The Council submits to the Annual General Meeting the report on the progress of the Association
• It is the apex policy making and decision making authority of the Association. It has the complete power to run the affairs of the institute component of the Association.
•  It also governs the functioning of the societal part of the Association. The Management Committee would however, have a significant autonomy in running the societal functions subject to reporting to the Council. 
• The Council is empowered to create posts in any category including supernumerary positions and or new departments/divisions/units subject to concurrence from the Department of Science & Technology, Government of India.