Hydrogel to aid wounds heal

Materials World magazine
19 Dec 2018

A cheap, injectable hydrogel has the potential to heal wounds quickly. Idha Valeur reports.

A newly developed hydrogel could aid wound healing by injecting it into the affected area. The gel will be particularly helpful for patients who already have compromised health. Currently, hydrogels tend to be used to mend skin tissue and encourage healing in irregularly shaped wounds, such as ulcers caused by diabetes.

However, the challenge has been that existing versions of injectable hydrogels are not porous enough, blocking neighbouring tissue from reaching the wound to assist with repair. But recently, researchers at the University of New Hampshire (UNH), USA, created a cheap and easy way to produce a more porous hydrogel using gelatine microgels.

Kyung Jae Jeong, Assistant Professor of Chemical Engineering at UNH, told Materials World that a porous network is important for interaction between the hydrogel and the neighbouring cells, saying, ‘Our work provides a very simple and cost-effective means to achieve that. Unlike other published approaches, our work does not require any chemical modifications. In addition, the starting materials of gelatine and microbial transglutaminase (mTG) are all edible and readily available at low costs’.

As Jeong says, gelatine use is beneficial due to it being available and economical, but also, the substance well known for its bioactivity. According to Jeong, gelatine possesses inherent cell-adhesive ligands, which human cells can use for adhesion, migration and proliferation. ‘Most synthetic polymers, like polyethylene glycol, require chemical modifications with such ligands,’ he said.

In the study, Injectable macroporous hydrogel formed by enzymatic cross-linking of gelatin microgels, published in ACS Applied Bio Materials, Jeong’s team detail how they compared common, non-porous gel with the new macroporous hydrogel, concluding that results show a significant increase in tissue cell migration inside the more porous hydrogel.

As well as being macroporous, the injectable hydrogel allows for the slow release of protein drugs, such as a platelet-derived growth factor. According to Jeong, the drugs are embedded within the polymer mesh of the hydrogel. ‘Proteins are slowly released by diffusion. Potentially, degradation of gelatine hydrogel can accelerate the process,’ he said.

Healing in the future

The researchers believe this new hydrogel may be able to aid other types of healing, such as of the skin, cornea and internal organs, for instance, following surgery.

‘This formulation can be applied to enhance wound healing [and] an animal study is underway,’ Jeong said. ‘We are also exploring the possibility of encapsulating stem cells in this porous hydrogel for tissue engineering and the manuscripts are in preparation.’

Jeong continued by explaining that faster curing is an obstacle they need to tackle before the hydrogel will be ready for real-world applications. He said an animal study to prove the in vivo efficacy will be needed, while clinical studies are a potential.

The researchers are now preparing for studies to be carried out on skin and corneas to determine their clinical applications. But progress is moving forward, as Jeong said, the technology has already obtained ‘many exciting results, from tissue engineering relating to bone and cardiac applications’.