Novel hydrogel jabs to deliver drugs

Harvard researchers, including those of Indian-origin, have developed a new biocompatible hydrogel that can be filled with cells or molecules and injected in the body to deliver drugs or stimulate tissue regeneration.
By tuning their shape, physical properties and chemical composition and infusing them with cells, biomedical engineers have successfully used hydrogels as three-dimensional molecular scaffolds.
Alginate hydrogels - made up of the polysaccharide naturally occurring in brown seaweed - are just such materials.
The rate at which the three-dimensional, internal molecular structure of alginates will degrade over time can be precisely tuned, which enables engineers to rationally design and control the release of drug molecules encapsulated in the gel.

Neel Joshi, from the Wyss Institute for Biologically Inspired Engineering at Harvard University, has developed a novel, truly biocompatible alginate hydrogel that can be synthesised using "click chemistry", which is a methodology for the quick and practical synthesis of substances using just a few reliable, chemoselective reagents.
The biocompatible click alginate gels are formed using chemical crosslinking strategies that allow engineers to entrap cells or molecules inside the gel without damaging them or rendering them inactive.

It presents a practical platform for long-term, stable encapsulation of bioactive materials. And, it is robust enough to be used in a variety of ways, which is exciting due to the variety of therapeutic drugs that are made from chemical and protein molecules, researchers said.

The click alginate hydrogel is robust and resists premature degradation and invasion by surrounding tissues.
"It's injectable, so it can be used to deliver cells or drugs to specific places in the body such as a location that has suffered a wound or has been invaded by a tumour," said Joshi.
Other types of hydrogels are much more cumbersome to synthesise, according to the study's first author, Rajiv Desai.
In contrast, the click alginate hydrogel can be created by a simple and fast combination of two simple solutions - similar to an epoxy.
And once the gel is formed, the click chemistry reactions are irreversible, resulting in a chemoselective hydrogel primed for use as a therapeutic scaffold.

The click alginate hydrogel is easily customised and modified, researchers said.
The research was published in the journal Biomaterials.