Research Highlight

Hydrogel delivers drugs to the colon

doi:10.1038/nindia.2016.135 Published online 19 October 2016

Researchers have synthesized a biocompatible hydrogel that can ferry drugs to the colon, alleviating infections and inflammation1.

Among various approaches, pH- and temperature-sensitive hydrogels had gained significant attention for their efficiencies to carry and deliver drugs to target organs.

To prepare these, the researchers chemically crosslinked biopolymer glycogen with a polymer N-isopropyl acrylamide in the presence of ethylene glycol dimethacrylate through a process known as free radical polymerization. They then tested the hydrogel’s efficiency to deliver drugs by loading it separately with two drugs — ornidazole and 5-amino salicylic acid. Both these drugs are widely used to treat colonic infections and inflammation. 

A sophisticated imaging technique showed that the hydrogel is porous and could slowly release the loaded drugs in a controlled fashion in solutions.

The hydrogel was non-toxic to human mesenchymal stem cells, suggesting that it is biocompatible. Since it could be degraded by an animal enzyme, it could be safely degraded and removed from the body after delivering its cargo.  

The hydrogel even retained its ability to release drugs after two months, indicating its stability. “The pH- and temperature-sensitive hydrogel could potentially be used for delivering other colon-targeted drugs,” says lead researcher, Sagar Pal from the Indian Institute of Technology, Dhanbad.  

The authors of this work are from: Polymer Chemistry Laboratory, Department of Applied Chemistry, Indian Institute of Technology (Indian School of Mines), Dhanbad; Biomaterials and Tissue Engineering Laboratory, School of Medical Science and Technology, Indian Institute of Technology, Kharagpur; and Discipline of Inorganic Materials and Catalysis, Central Salt and Marine Chemicals Research Institute (CSIR), Bhavnagar, Gujarat, India.


1. Patra, P. et al. Stimuli-responsive, biocompatible hydrogel derived from glycogen and poly (N-isopropylacrylamide) for colon targeted delivery of ornidazole and 5-amino salicylic acid. Polym. Chem. 7, 5426 (2016)